US1803688A - Lift truck - Google Patents

Description

May 5, 1931. A. M. BARRETT LIFT TRUCK Filed July 20, 1928 4 Sheets-Sheet l May 5,1931. A. M. BARRETT LIFT TRUCK 4 Sheets-Sheet 2 Filed yJuly 20, 1928 IrLilrLIlllrllLl h um mwN QN mwN @QQ um @N N mf N s @im May 5, 1931. A. M .BARRETT 1,803,688

LIFT TRUCK Filed July 20, 1928 4 Sheets-Sheet 3 gj, m MWL/am l. 1 @M @www fn" y (ifm May5, v1931. A. M. BARRETT LIFT TRUCK Filed July *20. 1928 4 Sheets-Sheet 4 I :Evi

Ziff" .r j fw .m JW., 1/ w m @di @t a .ff M f w W g Y L A @d f y #j j n? ,iff

f# w w J] V f l i@ m.

Patented May 5, 1931` ARTHUR M.

PANY, CF CHCAGO, ELLINOS,

tanins rarest ori-ice BARRETT, OF WINNETKA, ILLINOIS, ASSIGNORVTO IBARRETT-CRAVENS GDM- i CGRPORLTGN. OF ILLINQIS LIFT 'inUcK Appncatioi mea :any ao,

This invention relates to lift trucks comprising a main frame supported on wheels and arranged to be steered by means of a steering handle which also serves as alifting lever to raise a lifting frame mounted on the main frame so as to be capable of being raised or lowered with respect thereto. As is wellknown in the art, when the lifting frame is in its lowered position the truck isl adapted to be backed under a platform on which the load is placed, and then by operating the steering handle lthe lifting frame is raised to lift the platform with its load so that it can be transported and deposited in some other place. The invention has more particularly to do with suoli lift trucks adapted for transporting comparatively heavy loads, in' which the lifting frame is raised by a4 plurality of strokes of the lifting handle, commonly from those in which the platform is raised tothe limit of its upward movement by a single continuous stroke of the handle. f

lt has for its objects to provide a multiple lift truck in which the lifting frame may be raised by a substantially uniform application of power throughout the range of movement of the lifting handle; to provide improved operating connections between the lifting handle and the lifting frame for ap-V plying lifting force to the latter; to provide improved means for holding the lifting frame against descent at all stages of its upward movement, and for controlling its downward movement; to provide improved means for starting the downward movement of the lift- Y ing frame, and to improve the construction and operation of trucks of this description in various other respects which willfbeparticularly pointed out in the course of the description of the embodiment' of my invention illustrated in the drawings.

fn the accompanying drawings I have illustrated a lift truck in which. my improvements are embodied inthe form that l consider preferable, and Iv shall now describe specifically the truck illustrated therein, but it is to be understood that the generic features of my invention may be embodied in various other forms, as will be manifest to 192s. serial No. 294,1?9.

those skilled in the art, and, therefore, the

claims hereinafter made are not intended to p handle in horizontal section;

Fig. is a substantially central longitudinal.v vertical section showing the lifting frame in its lowermost position, the rear portion of the truck being omitted; 'termed multiple lift trucks, as distinguished Fig. 4 is a view similar to Fig. 3 with the lifting frame partly raised, and the lifting devices in the position they occupy at the completion of a full downward strolre of the lifting handle; i Y

Fig. 5 is an enlarged detail illustrating part of the lifting mechanism, being` a vertical cross-section on line 5 5 ofFig. 3;

Fig. 6 is an enlarged detail illustrating part of the lifting mechanism, being va vertical cross section on line 6-6 of Fig. 3;?

Fig. 7 is an enlarged detailA illustrating part of the lifting mechanism, being a substantially horizontal section on line 7 7 of Fig. 3; y

Fig. 8 is an enlarged detail of part of the holding mechanism, being a vertical crosssection on line 8-8 of Fig. 2; i

Fig. 9 is an enlarged detail of part of the holding mechanism, being a horizontal section on line 9-9 ofFig. 8;

Fig. l() is an enlarged detail of part of the holdin@ mechanism, being a Vertical crosssection on lines lO-lO of Figs. 2 and9, and

Figure l1 is a detail in elevation showing kthe pawl releasing mechanism and corresponding to a view taken substantially along the line 11-11 of Figure 2.

inthe present instance I have shown my improvements embodied in a lift truck `in which the wheel supported main frame 13 comprises two parallel side bars 14e, 15, which are firmly held at their forward ends in fixed relation to each other` by securing them to the opposite ends of a transverse cross-head 1G, as best shown in Fig. 2, the end portions 1'?, 18 of which extend downward to the points of their connection with said side bars. ln the illustrated construction these parts are connected together by rivets 19, best shown in Fig. 1. The cross-head 16 is provided with a central downwardly projecting tubular boss 20 which forms a bearing for a vertically disposed king bolt 21 tnat is connected with the steering wheel or wheels. ln the present instance two steering wheels 22 are provided, mounted upon the opposite end portions of a transverse front axle 23 that extends through a hole in trie lower portion of the king bolt 21 and through a horizontally disposed spacing sleeve 211 mounted on said axle between the wheels. This leeve provided with a hole that is alined with the bore of the boss 20, and the lower end of the king bolt 21 fits in said opening, thereby holding the sleeve 24 in place. As shown in Fig. 3, a set screw 25, screwed in the lower end of the king bolt 21 so that it binds against the axle 23, holds the axle against endwise movement. Between the lower end of the boss 2O and the upper surface of the sleeve 24C I preferably provide an anti-friction bearing to reduce friction between these two members and make steering easier. ln the illustrated construction this anti-friction bearing comprises an inner annular raceway 2G supported by the sleeve 24, an outer annular raceway 27 fitted in a pocket in the lower end of the boss 20, and tapered rollers 28 interposed between said raceways, to sustain the downward thrust of the loa-d.

These bearings may if desired be made adliustable in any suitable way. Since the mounting of roller bearings of this kind so that they may be adjusted is not new, it is deemed unnecessary to illustrate means for that purpose.

1t will be apparent from the foregoing description that the front portion of the main frame, with the load imposed thereon, is movably sustained by the front wheels through the boss 20, the sleeve 211 and the axle 23, and that the wheels may be turned to steer the truck by rotating the king bolt 21 about a vertical axis. For steering purposes the kinor bolt 21 is provided with a steering head 29 mounted thereon above and bearing upon the upper surface of 'the cross-head 16, said steering head being non-rotatably secured to the king bolt in any suitable way as by a pin 30, as shown in Figs. 3 and t. A steering handle 31, which also serves as a lifting lever, is pivotally connected at its lower end by a transverse bolt 32 with upwardly and .forwardly projecting ears 33 carried by the steering head, so that said steering handle may swing up and down, and may also be used to rotate the steering head. In the illustrated construction the steering handle 31 comprises two bars 34, best shown in Fig. 2, spaced apart at their lower ends and arranged to lie adjacent to the outer faces of the ears 33, with which, as above stated, they are pivotally connected by the bolt or pin rl`he outer ends of the bars 3a are connected together in any suitable way, and are pro- 7ided with the usual cross-bar 3121 by which the operator swings said handle to raise the lead and to steer the truck.

Also pivoted upon the bolt 32 and located between the ears is a shackle member in the form of a horn 35 that extends rearwardly and upwardly from the pivot 3. back of the handle 31, its upper end beingT adapted to swing toward and from the handle and to be connected therewith by a latch 3G carried by 'the handle, as best shown in Figs. l, 3 and el. This latch is pivoted on the handle between the side bars by means of a pivot 37 so that it rocks about a horizontal axis. At its rear end it is provided with a hook 33 adapted to engage a hook 39 at the upper end of the horn 35, and at its forward end it is provided with an arm 40 that e3:- tends aeross one or both of the bars 3-1 of the steering handle and serves to limit the downwar l movement ot the rear end of the latch. ythe latch is also provided with a counterbalance weight #l1 that is adapted to hold it either in a downwardly and rearwardly iii-- clined position, as shown in Figs. 1 and 3, or in an upwardly and rearwardly incli ied position at approximately ninety degrees from the position shown in Fig. 4. il depending arm 41", also carried by the latch 36, is adapted to strike the horn 35 when the steering handle is moved rearwardly, to posil tively move the hook 33 into position to engage the hook 39. The horn is provided near its lower end, and at a point back of the pivot 32, with a transverse lug or stop l2 that is adapted to engage the upp r surface of the steering head 29 when the horn is in an approximately vertical position, to keep the horn from swinging back further while permitting it to swing forward when actuated by the steering handle during the operation of lifting the load.

It will be apparent that by swinging the steering handle rearwardly the latch 3G will automatically engage over the upper end of the horn 35, thereby operatively connecting the steering handle with said horn. It then the steering handle be swung forward and downward, the horn 35 will swing with it, both parts turning about the pivot 32. The horn 35 will also swing laterally about the vert-ical axis of the steering head when the handle is operated to steer the truck. it serves to transmit power applied to the steering handle to the lifting mechanism by which the lifting frame is raised, as will presently be described. y

The rear ends of the side bars 14, 15 of the mainframe are ypreferably supporte/t` upon and secured to a non-rotating rear axle 43, as best shown in Figs. 1 and 2, whichaxle entends through holes in, and is pinned to the rear end portionsof, said side bars, and carries the rear Wheels 44 of the, truck. l/Vhere a non-rotating rear axle is used 'the rear Wheels preferably are not mounted directly upon the aille, but are carried by suitable anti-friction devices such as those shown and described in my pending application, Serial No. 207 ,451, filed July 21, 192'?. They may, however, be supported in any other suitf able way.

The rear end portions of the side bars 14, 15 are rmly secured together and spaced apart by a transverse angle bar 45, best shown in Figs. 1 and 2, located between said side bars and having its end portions secured to angle brackets 46, 47, respectively fastened to the side bars 14, 15 in any suitn able Way, as by rivets 48, 49, as shown in Fig. 2. This transverse bar also serves to supportr certain other parts of the mechanism, as will. be hereinafter explained.

The lifting frame is rectangular in form and is b-est made of a bar bent to U-shape toV provide parallel side members 50, 51 that overlie the side bars 14, 15, respectively, and a transverse rear end member 52, as best shown in Fig. 2. The side members 50, 51 are connected together near their front ends by a transverse U-shaped cross-head 5S, preferably in the form Vof a casting, which is provided with downturned ends 54, 55 that fit against the inner faces of the side members 50, 51, asbest shown in Fig. 5, and are firmly secured thereto in any suitable way,

by bolts or rivets. Vrlhe cross-head 53 projects upwardly beyond the side members 50, 51, as shown in Fig. 1, and serves to limit the extent to which the truck may be shovedV under a load carrying platform. Vlt also functions as an abutment to sustain the hrting thrust and transmit it to the side bars of the `frame during the-'lifting operation,

will be described later. The rear end portions ofthe side members 50,51, are connected and braced by a transverse anglebar 56, as shown in Fig. 2, which bar serves also as a bearing member for the lifting connections at the rear end ofthe truck.

The lifting frame is supported on the main frame for vertical, or Vup and down, movement with respect thereto by means of swinging links at the front and rear end portions of said frames. The front links, indicated off the reference numerals 57, 58, are pivotally connected at'their lower ends to thel front portions of the side bars 14,15 by bolts 59, 60, as shown in -Figsf1 and 2, the

with the front ends of the side members 50, 51 of the lifting frame by bolts 61, 62, respec-` tively. rlChe links that support the rear portion of the lifting frame on the main frame are indicated by the numerals 63, 64, the lower ends of which links are pivotally supported by the rear axle 43. l

As also shown in Figs. 1 and 2, the upper ends of the links 68, 64 are journaled on studs at the opposite ends of a cylindrical bearing member 65V that is adapted to bear in the inner Vangle of the angle bar 56 that is secured to the rear portion of the lifting frame, as indicated by Vdotted lines in Fig. 1, said bearing member being also pivotally supported upon the rear axle 48 between the roar wheels 44 by arms 66, 67, as best shown in Fig. 2. Preferably, the parts 65, 66, 67 vare in the form of av unitary casting. It will be noted that by this construction the lifting frame is supported on the rear axle by two supporting members at each side of the truck, the supporting members of each pair being located at opposite sides of the corresponding wheel 44, so that the rear portion of the lifting frame is very stably supported.

The several links supporting the lifting frame are arranged to occupyan upwardly and rearwardly inclined position when the lifting frame is in its downV or load receiving position, so that by drawing the lifting?,I frame forward with reference to theinain `frame said links will swing ina clockwise direction as viewed in Fig. 1 to raise the lifting frame and lift the load for transport.

The lifting mechanism for raising the lifting frame, as has been remarked, is operated by the steering handle 31, which constitutes also a lifting lever, and it comprises means for moving the lifting frame endwise to accomplish its vertical movement through the action of the swinging links that support it on the main frame. .ltv should be explained here that the term vertical movement7 is here used to define up and down movement of the Vlifting frame in a vertical plane whether such movement be accompanied by endwise movement of the lifting frame or not.' ln the .construction described the lifting frame and 'operatively connected with the steering handle so that it may be actuated thereby, in connection withv ratchet mechanism also mounted onthe main frame and connected by one or more pitmenrwith the lifting frame through the cross-head 53 so that upward and ss" Y forward end thrust is applied to the lifting frame by the oper tion of said lever, and the lifting frame thereby is swung upward and forward on the links 57, 58 and 63, 6.

Tl e arrangement and organization of this lifting mechanism as a whole is best shown in Figs. 1 to 7. lt comprises a transverse shaft 68 which is supported by the side bars 111, 15 of the main frame, a short distance back of the cross-head 59, by supporting blocks 69, 70 having depending arms 71, 72 that lit against the inner faces of the side bars 11i, 15 of the main frame and are rmly secured thereto, as by rivets 73, as best shown in 1Eig. 6. As there shown, the arms 7l, 72 are offset slightly so that ie outer ends of the blocks 69, 70 do not contact with the inner faces the side ba 50, of the lifting frame. rlhe shaft 68 need not rotate, and, therefore, it may be mounted in the supporting` blocks 69, 70 in any suitable Mounted on the shaft 68 between the inn ur onus of the blocks 69, 70 is a sleeve 7l prov al t 1 opposite ends with cranks 75, 76 and wrist pins 77, 78, respectively, and separately earried by said sleeve between said cranks is a toothed sector 79, the teeth of which are located at the forward side of s d sleeve. The sleeve 7 Ll also is provided with rearwardly extending ears 81, 82 for the attachn'ient thereto of the means for holding the lifting frame in its elevated position, as will be hereinafter described. Between the ears 8l, 82 and thc adjacent cranks 75, 76 are bearings` surfaces 83, 84 to receive the rear ends of a pair of parallel lifting levers 85, 86 which are fulcrumerL on said sleeve and extend forward and downward therefrom at opposite sides of the ratchet sector 79, as best shown in Fig. 7.

ln the construction illustrated these levers are pivotally secured upon the sleeve 74 by clips 87. 88, respectively, that extend around the under sides of the sleeves 74 and are lli ` bolted to the levers 85, 86 at opposite sides of said sleeve by bolts 89, 90, best shown in Figs. 1 and 2. Thus the levers 85, 86 are pivotally mounted upon the sleeve 74e to swing vertically coaxially with said sleeve. lNhile l prefer to use two of the lifting levers 85, 86. as described, it is apparent that a single lever could be used if desired, but the construction shown is more efficient as it provides a better support for the pawl hereinafter described by which the sleeve 74 is rocked to lift the lifting frame, as will be presently described.

The forward ends of the levers 85, 86 are connected together by a cross-pin 91, as best shown in Figs. 5 and 7, which serves also as a part of the connections between said levers and the steering handle. Such connections comprise a three-armed or bell-crank lever 92 having a forwar ly disposed arm 98 that is fulcrumed at 94 between rearwardly projecting ears 95 carried by the steering head 29; an upwardly extending arm 95 that is connected by a link 96 with the horn 35, and a rearwardly extending` arm 97 that is connected by a pivot 98 with the upper end of an extensible rod 99, the lower end of which is connected with thc forward arms of the levers 85, 86 by the pin 91, as best shown in Fig. 1. The link 96 has an eye 100 at its forward end through which is inserted the horn 85, and at its rearen d is provided with an eye 101 which receives a pivot pin 102 mounted in the upper arm 95 of the lever 92.

The latter lever is preferably bifurcated as shown in Fig. 2, and the pin 102 extends through both members thereof, the rearwari end of the link 96 lying between the two members of said lever. Preferably the lever 92 is provided with registering holes 103 adjacent to the holes that receive the pin 102, but lying` nearer the fulcrum point of said lever, so that the connection between the rear end of the lever 96 and the lever 94 may be shifted toward or from said fulcrum point to vary the leverage. The extensible link 99 comprises upper and lower screw-threaded members 104, 105 connected by a right and left hand screw 106, so that by means of said screw the length of the link may be adj usted. The lower member 105 fits between the two levers 85, 86, as best shown in Fig. 5.

1t is obvious that by means of the connections just described the lifting levers 85, 86,

which, as has been suggested may be considered as a single lever, may be swung ver tically about its fulcrum 68 by swinging the steering handle 31 up and down while the latch 36 is in engagement with the hook 35. Assuming the parts to be in the position shown in 1, by swinging the steering handle 81 forward and downward the latch 36 will be drawn forward, thereby rocking the bell-crank lever 92 in a clockwise direction about its fulcrum 94. This through the link 99 will pull the forward ends of the levers 85, 86 upward, swinging' them about the shaft 68 as a fulcrum. rlhis movement of the levers 85, 86 is made effective to rock the ratchet member or notched sector 79 in a counterclockwise direction about the shaft 68 by means of a pawl 107, best shown in Figs. 3 'and l,

which pawl is pivoted between the levers 85, 86 upon a pivot pin 108 in such position that its free end is adapted to engage the teeth 80 of the ratchet member 79.

A spring 109 placed between the pawl 107 and a liXed stop 110 carried by the levers 85, 86 serves to hold the pawl 107 yieldingly in engagement with such teeth. Thus, when the levers 85, 86 swing upward the pawl 107, through its engagement with the ratchet member 79, will rock said ratchet member upwardly about the shaft 68 as an axis. When the steering handle is again moved upward the pawl will ride downwardly over theteeth of the ratchet member to a greater Y or less extent, depending on the length of the `upward stroke of the steering handle.

.'1`lie1efore, the ratchet member may be swung through a greater or less arc for each downward stroke of theV steering handle, depending on the length of such stroke,

Rocking the ratchet member 7 9 in the manner described is made effective to lift the lifting frame by means of pitmen 111, 112 that are journaled at their lower ends upon the wrist 77, 78, respectively, and entend upward and forward Vto the cross-head y53 with which they are connected by pivot pins 113, 114, respectively, asbest shown in Fig. 5, these pins being mounted in pairs of cars 115, 116, at opposite sides of said cross-head as shown in said figure. Swinging of the ratchet member 79 in a countercloclwise direction as viewed in Figs. 3 and 4 will swing the cranks 75, 7G in the same direction, which, through the pitm-en111, 112,' will thrust upward and forward on the cross-head 53, thereby causing the lifting frame to 1ise on the links 57, 58 and 63, 64 which support it on the main frame.

i4s the lifting frame rises it must, of course, be held up during the return or upward strolre of the steering handle, and for this. purpose holding means is provided. This holding means comprises a holding rod 117, the forward portion of which is sorewthreaded as Vshown at 118 in 1*`igs.3 and 4. Said. rod extends longitudinally of the central portion of the main frame, and its forward portion lieswithin a cylinder 119 which is pivotally connected at its forward end by a pivot 120 with the ears 81, 82 that project rearwardly from the sleeve 74, as previously described, so that as the sleeve 7 4 rocks about the shaft G8 as an aXis the cylinder 119 is moved longitudinally of the truck frame in one direction or the other. Mounted in a fixed position in the cylinder 119, about midway of its length, is a. screw-threaded sleeve or nut'121 which is engaged by the Vscrew-threaded portion of the holding rod 117. The pitch of'these screw threads is such that reciprocation of thev cylinder 119-V with respect to the holding rod 117 .causes rotation of said rod in onedirection or the other. A piston 122 .is carried by the rod 117 at its forward end andworks in the forward portionV of the cylinder 119, so that said cylinder and piston function as a dashpot to checl the descent of the lifting frame, as will be hereinafter furtherrexplained. .Y

rlfhe holding .rod4 117` passes Ythrough a stuffing box 123 at the rear end of the cylinder 119, and the rear end of said rod is rotatably connect-ed withthe main frame in such` manner as to hold said rod against endwise movement, sovthat said rod may becaused to rotate hv reciproca-tion of the cylinder 119. To enable the holding rod 117 to function as holding means to prevent descent of the lifting frame it is necessarythat it be normally held against rotation by rearward movement of the cylinder 119, while it remains free to rotate in the opposite direction by forward movenient of said cylinder. To this end a ratchet wheel is mounted upon the rear end of the rod 117 and is keyed thereto, preferably by means of a pin 125 that passes through the hub 126 of .said ratchet .wheel and through the rod 117. having a recess 231to receive it. At the bottoniv of such recess is an end thrust ball bearing that receives the end thrust of the rod 117. This arrangement is best shown in Figs. 4 and 9. ball 129 lies between a bearing block 130 interposed between it and the rearendof the rod 117, and a bearing block 131 interposed between it and a transverse pin 132 by which the bloeit is secured between standards 133, 134 that rise from the angle bar 45. A

bearing plate 135 extends across the front face ofthe bearing block 127 and the front face of the ratchet wheel 124, and is secured to the bloclr 127 by bolts 136, 1,37.

A. series of anti-friction balls 138 are provided betweenV the rear face of the bearing plate 135 and the front face of the ratchet wheel 124, said balls traveling` in raceways provided to receive them, as shown in F ig. 9. 'Fliese balls support the ratchet wheel during roi-ward pull on the holding rod 117 incident to the lifting operation, and the ball 129 taires the rearward end thrust on the holding rod 117 due to the load sustained by the lifting frame. llhe rod 132 provides a pivotal support for the bloclt 127 which permits `such `block to swingup and down to such extent as may be necessary in the operation of the lifting mechanism. y y i llonorm ally hold the ratchet wheel 124 and rod 117 againstrotation in one direction while permittingV them to rotate in the opposite direction pawls 139, 140 are provided at opposite .sides of the ratchet wheel, as best Vshown in Figs. 8 and 9. Said pawls are mountedon pins 141, 142, respectively, supported by the block 127 and plate 135 at opposite sides of the ratchet wheel, as shown in said figures. lhese pawls are provided respectively with downwardly .extending arms 143, 144 that are engaged by a transverse rod 145 on which are mounted springs 146,147 that respectively bear against said arms in the proper direction to move the pawls 139, 140 into engagement with the teeth of the ratchetwheel 124. The outer end of the spring 146 bears against a nut 148 .screwed on'the rod 145, and the corresponding end of the spring 147 bears against a collar 149 held in Vplace on the rod 145 by a pin 150, as shown in Fig. 8.

Nuts 151, 152 screwed on the rod 145 a opposite sides of the arms 143, 144 from the r he hub is journaled in a block 127 l ris shown in the latter ligure, the

pawls 139, under the action of said springs, and also provide for moving said pawls simultaneously out of engagement with the ratchet wheel by endwise movement of the rod toward the right as viewed in Fig. 3. For moving the rod 145 endwise in either' direction to control the position of said pawl it is provided with a projecting end 153 that passes through an eye 154 in an arm 155 that projects rearwardly from a vertical shaft 156 mounted in a sleeve bearing 157 carried by a plate 153 that is secured to the bearing plate 135 by the bolt 137 and another bolt 159, as shown in Figs. 9 and 10. Nuts 160, 161 screwed on the end 153 of the rod 145 at opposite sides of the arm 155, as shown in Figs. 8 and 9, cause the rod 145 to move endwise when the arm is swung in one direction or the other by the rocking of the shaft 156. Said shaft carries a cross-head 162 at its upper end that entends transversely of the truck frame, as shown in Figs. 2 and 10, one end of said cross-head being connected by a connecting` rod 163 with a downwardly projecting arm 164. shown in Figs. 3 and 4, that is connected to a pedal 165 mounted on the front crosshea d 16 of the truck, preferably by means of a pin 166, as shown in Fig. 2. rIhis pin is mounted between ears 167 that rise from the cross-head 16 near one end thereof, as shown in 2. A spring 168 tends to press the pedal 165 upward, and consequently to exert slight forward pull on the rod 163.

Manifestly, by depressing the pedal 165 the rod 163 will be moved rearwardly, thereby rocking the cross-head 162 in a countercloclwise direction as viewed in F 2. This will move the arm 155 to the right as viewed in Fig. 9, thereby moving` the rod 145 in the same direction, which will move the pawls 139, 140 out of I ngagement with the ratchet wheel 124. When this occurs it leaves said ratchet wheel and the holding rod 117 free to rotate in a direction to permit the descent of the lifting' frame.

To permit the lifting frame to descend it is, of course, necessary that the pawl 107 that forms a part of the lifting mechanism be ioved out of engagement with the net-shed sector 79 at the same time that the pawls 139, 140 are out of engagement with the ratchet wheel 124. To accomplish this the crosshead 162 is connected at its opposite, or inner, end with a trip rod 169 that extends forward alongside the cylinder 119, its forward end preferably lying between the lever 86 and the notched sector 79, as shown in Fig. 2, and resting on the upper surface of the sleeve 74, as shown in Figs. 2 and 6. r1`he forward end of this trip rod is adapted to engage a lug 170 at the outer end of the pawl 107 when said trip rod is moved forward, to move said pawl, against the tension of the spring 109, out of engagement with the teeth of the sector 79. This forward movement of the trip rod 169 occurs when the release rod 163 is moved rearwardly to release the ratchet wheel 124, since said rods are connected to opposite ends of the cross-head 162, and when the crosshead 162 rocks in the opposite direction under the action of the spring 168 upon the release of the pedal 165 from pressure, the pawls 139, 140 are permitted again to engage the ratchet wheel 124, and the trip rod 169 is moved rearwardly to permit the pawl 107 to return to operative relation to the sector 79. Thus, whenever the pedal 165 is operated to permit the descent of the lifting fra-me the sector 79 and also the ratchet wheel 124 are simultaneously released to permit reverse movement thereof.

To start the descent of the lifting frame, particularly when it carries no load, springs 171, 172 are provided at opposite sides of the truck, said springs being mounted respectively on rods 173, 174 that are pivotally connected at their lower ends with the side members 14, 15 of the main frame by bolts 175, 176, as shown in F ig. 2. These rods extend upwardly and rearwardly, their rear ends passing through holes in angle plates 177, 178 secured to the inner faces of the side 1nembers 50, 51 of the lifting frame and receiving the end thrust of the springs 171, 172. By this arrangement, when the lifting frame is moved forward and upward, these springs are put under tension, which increases as the lifting frame rises, and, therefore, they tend to move said frame downward aga-inst the resistance offered by the dashpot check.

The operation of my improved truck is as follows Vhen the liftingl f ame is down the parts occupy the position shown in Figs. 1 and 3, except that the lifting handle may or may not be upright. When it is desired to i lift a load the lifting handle is moved to its upright position so that it is latched to the horn 35. By then pulling the handle forward and downward the bell-crank lever 92 is caused to rock in a clockwise direction, thereby lifting the forward ends of the lifting levers 85, 86. This rocks the notched sector 79 in a counterclockwi se direction and operates the pitmen 111, 112 to thrust forward and upward on the cross-head 53 of the lifting frame so that said frame rises on the links 57, 58, 63, 64 that support it on the main frame. rllhis rocking movement of the notched sector 79, and the sleeve 74 that is integra-l with it, draws the cylinder 119 forward, thereby rotating the holding rod 117 and ratchet wheel v124 in a clockwise direction as viewed in Fig. 8. The position of the parts when the lifting frame has been partly lifted is shown in F ig. 4. During the return or upward stroke of the steering handle the lifting frame is held against descent by the holding rod 117 through the nut 121 in the cylinder 119, because the rearward movement of said cylinder necessarily incident to down ward movement of the lifting frame is prevented because the holding rod 117 prevented from rotating in the opposite direction by-engagement of the pawls139, 149 with the ratchet wheel `124.-. 'llhe lifting frame may be further lifted by succeeding strokes of the steering han-:lle until it reaches its maximum height, which lifting operation puts the springs 171, 172 under tension, as has been described.

lVhen it is desired to lower the lifting frame, the voperator depresses the pedal 165, thereby rocking the cross-head 162 to move the pawls 139, 14,0 out of engagement with the ratchet wheel 124, and at the saine time move the pawl 107 out of engagement with the notched sector 79. rllhis permits the lifting frame to start down under the action of the springs 171, 17 2, its desc-ent being checked by the piston 122 in the cylinder 119.

It will be noted that when the lifting frame is down Vthe cranks 75, 76 extend downwardly and rearwardly so that the pitmen 111, 1l2 lie close to the shaft G8, as shown Vin Fig. 1, and that as said cranks are swung to raise the lifting frame the wrist pins 77, 78 move further away from said shaft, thereby decreasing their' leverage. As this Voccurs the steering handle moves: downward into a more favorable position for the application of power to the lifting mechanism, with the result that the lifting effort required during thelifting operation is made practically uniform throughout such` operation, which is a desirable quality in trucks of this description. If it be desired to obtain greater speed for a given stroke of the steering handle in lifting the load, the link 96 may be shifted from the position shown in Fig. l

to connection with the pin 103 of the lever 92.

What I claim as my invention and desire to secure by Letters Patent, is

1. In a lift truck, the combination with main and lifting frames andy a steering handle, of means operable by said steering handle to lift the lifting frame comprising .a rocking member mounted onY the main frame, a lifting lever fulcrumed to swing concentrically with the axis of Vsaid Vrocking member and connected with said steering handle to be actuated thereby,l pawl and ratchet mechanism operatively connecting said lifting lever and said rocking member for rocking the same tojlift the lifting frame, lifting means connecting said rocking ineinber with the forward portion of the lifting frame, holding means interposed between said rocking member and the rear portion of the main fram-e for normally holding the ifting frame against descent, andrneans operable to releasesaid holdingmeans.

2. In a lift truck, the combination withV main and lifting frames and a steering handle, of means operable by said steering handle to lift the lifting frame comprising 8. In a lift truck, the combination with 'I main and lifting Vframes and a steering handle, of means operable by said steering handle to lift the lifting frame comprising a transverse shaft mounted ou th-e main frame,

a ratchet member supported by said shaft to i rock coaxiallytherewith and operatively connected with the lifting frame, a vlifting lever i'ulcrumed to swing eoaXially with said ratchet member and connected with'said steering Vhandle to. be actuated thereby, a pawl carried 2 by said lifting lever and adapted to engage said ratchet member to rock the same to lift the lifting frame, holding means interposed between said ratchet member and the rear portion of themain frame for normally holding the lifting frame against descent, and means operable to release said holding means.

d. In a lift truck, the combination with main and lifting frames and a steering handle, Vof means operable by said steering handle tov lift the lifting frame comprising va cranlrmounted on the mainY frame, a pitnian Vconnectingcsaidcrank with the lifting frame, a lifting lever fulcruined to swing coaXially with said crank and connected with j said steering handle to be actuated thereby, pawl and ratchet mechanism operatively 4cpo-nnectingV said lifting lever and said crank for rocking the 'same to lift the lifting frame, and holding means connected with said lifting means and with the main frame for normally holding said lifting frame against descent.

5. In a lift truck, the `combination with,

main and lifting frames and asteering handle, of means'operable by saidsteering handle to lift the lifting frame comprising a crank mounted on the main frame, a pitman connecting said crank with the lifting frame, a lifting'lever fulcruined toswing coaiiially with said crank and connected with said steer- `holding vmeans connected with said crank and with the main frame for normally holding said lifting frame against descent..

' 6. Infra lift truck, the combination with main and lifting frames and a steering hanamY -ing handle to be actuated thereby, pawl andY dle, of means operable by said steering handle to lift the lifting frame comprising a downwardly and rearwardly extending crank piifotally mounted on the main frame to turn about a transverse axis, a pitman extending forward and upward from said crank and connected with the lifting frame, a ratchet member connected with said crank, a lifting lever fulcrumed on the main frame, a pawl carried by said lever and engaging said ratchet member for actuating the same, and means operatively connecting said lifting lever with the steering handle.

7. 1n a lift truck, the combination with main and lifting frames and a steering handle, of means operable by said steeing handle to lift the lifting frame comprising a downwardly and rearwardly extending` crank pivotally mounted on the main frame to turn about a transverse. axis, a pitman eX- tending forward and upward from said crank and connected with the lifting L", rame, a ratchet member connected with said crank.y a lifting lever fulcrumed coairially with said crank and extending forward therefrom, a pawl carried by said lever and engaging said ratchet member for actuating' the same, and means operatively connecting said lifting lever with the steering handle.

8. In a lift truck, the combination with main and lifting frames and a steering handle, of means operable by said steering handle to lift the lifting frame comprising a downwardly and rearwardly extending crank pivotally mounted on the main frame to turn about a transverse axis, a pitman extending forward and upward from said crank and connected with the lifting frame, a ratchet member connected with said crank, a lifting lever fulcrumed coaxiallv with said crank and extending forward therefrom, a pawl carried by said lever and engaging said ratchet member for actuating the same, and means including a vertically swinging lever fulcrumed on the main frame and connected respectively with said lifting lever and with the steering handle for actuating said lifting lever.

9. In a lift truck, the combination with main and lifting frames and a steering handle, of means operable by said steering handle to lift the lifting frame comprising a downwardly and rearwardly extending crank pivotally mounted on the main frame to turn about a transverse axis, a pitman extending forward and upward from said crank and connected with the lirting frame, a ratchet member connected with said crank, a lifting lever fulcrumed coaxially with said crank and extending forward therefrom, a pawl carried by said lever and engaging said ratchet member for actuating the same, and means operatively connecting said lifting lever with the steering handle, the latter means including a vertically swinging lever fulcrumed on the main frame, a connection between said lever and the lifting lever, and a connection between said vertically swinging lever and the steering handle adjustable to vary the leverage of the steering handle on the latter lever.

l0. In a lift truck, the combination with main and lifting frames and a steering handle, of means operable by said steering handle to lift 'the lifting frame comprising a downwardly and rearwardly extending crank pivotally mounted on the main frame to turn about a transverse axis, a pitman extending forward and upward from said crank and connected with the lifting frame, a ratchet member connected with said crank, a lifting lever fulcrumed coaXially with said crank and extending forward therefrom, a pawl carried by said lever and engaging said ratchet member for actuating the same, and means operatively connecting said lifting lever with the steering handle, the latter means including a vertically swinging bell crank lever fulcrumed on the main frame, means connecting one arm of said bell crank lever with the steering handle, and means connecting another arm of said bell crank lever with the lifting lever.

ll. ln a lift truck, the combination with main and lifting frames and asteering handle, of means operable by said steering handle, to lift the lifting frame comprising a crank mounted on the main frame, a pitman connecting said crank with the lifting frame, a lifting lever fulcrumed to swing coaxially with said crank and connected with said steering handle to be actuated thereby, a ratchet member connected with said crank, a pawl carried by said lifting lever and enga ging said ratchet member for actuating the same by the operation of said lever in one direction, means operable to move said pawl out of operative relation to said ratchet member to permit descent of the lifting frame, and means interposed between said crank and the rear portion of the main frame for normally holding the lifting frame against descent.

l2. In a lift truck, the combination with main and lifting frames and a steering handle, of means operable by said steering handle to lift the lifting frame comprising a crank mounted on the mainv frame, a oitman connecting said crank with the liftin ame, a lifting lever fulcrumed to swing coaiiially with saitL crank and connected with said steering handle to be actuated thereby, a ratchet member connected with said crank, a pawl carried by said lifting lever and engaging said ratchet member for actuating the same by the operation of said lever in one direction, means between said lifting means and the rear portion of the main frame for normally holding the lifting frame against descent, and means operable to move said pawl out of operative relation to said ratchet same by the operation of said lever vin one` direction, means 'connected With saidcranlr and With the main frame for normally holdingthe lifting frame against descent, and

f means operable to move said paWl out of operative relation tov said ratchet member and to simultaneously release said holding means.

14. In a lift truck, the combination with main and'lifting frames and a steering handle, of means operable by said steering handle tolift the lifting vframe comprising a cranlrmounted on the main frame to rock about a transverse axis, a cross-head secured to the lifting frame, a pitman `connecting said crank With said cross-head, av ratchet member connected With said crank, a lifting lever fulcrumed concentrically With the axis of said crank, a paWl carried byY said lifting lever and enga-ging said ratchet member, means operatively connecting: said lifting lever vvith said steering handle, and means interposed between said crank and the main frame vfor normally holding the lifting frame against descent. y

15. In a lift truck, the combination With mainand lifting `frames and a steerfng handle, of means operablefby said steering han- Vdle to lift `the lifting frame comprising spaced cranks mounted on the main frame to rock about a transverse axis, pitmen connect ed With said `cranks i and vvith the lifting frame, a ratchet member located between yand connected With saidcranks to turn therewith, a lifting lever including spaced members fulf crumed'on the main frame coaxially .Withsai'd crank members and said ratchet member, a pavvl carried by said liftinglever and engaging said ratchet member, means operatively connecting said lifting lever with the steering handle,` ,and means connected With said crankssand With the main frame fornormally holdinofrthe lifting frame against descent.

16,; n a `lift truclnthe combination with main ,and lifting frames, a steering handle, and means operable by said-handle to lift the liftingfram'e, of means 4for holding the lifting. frame against descent comprising cooperating 'rotatable and nonrotatable members Y movable :longitudinally relatively to` each other by` rotation of said rotatable member,

one of said members being connected With said lifting means to move therewith longitudinally of the other member, the latter member being connected With the vmain frame, and paWl and Vratchet means for normally holding said rotatable member against "rotation in a direction to permit descent of the lifting frame, While permitting it t0 r0- tate in the .opposite direction. i

17.` In a lift truck, the combination With main and lifting frames, a steering handle, and means operable by said handle torlift the lifting frame, of means for holding the lifting frame againstdescent comprising cooperating rotatable and nonrotatable members movable longitudinally relatively to cach other by rotation ofisaid rotatable member, said nonroatable member being connected with said lifting means to be moved longitudinally bythe actuation thereof, and said rotatable member having a thrust bearing onl the main frame, and pawl and ratchet means on the main frame for normally holding said rotatable member against rotation in a-direction to permit descent Vof the lifting frame,vvhile permitting it to rotate in the opposite direction.

18.l In a lift truck, the combination with main and lifting frames, a steering handle, and means operable by said handle to lift the lifting frame, of means `for normally holding the lifting frameV against descent comprising a, rotatable screw-threaded rod mounted atone end lupon the main frame, a

`nonrotatable nut threaded on saidvrod and movable thereon to rotate ,the sameby up or down movement of the lifting frame, and releasable ratchet means for normallyholding said rod against rotation in a direction to permit descent of the lifting frame, While permitting it to rotate in theopposite direction. Y

19.` In a lift truck, the combination With main and liftingframes, `a steering handle, and means operable by said handle to lift the lifting frame, Vof means fornormally holding the lifting frame against descent comprising a rotatable screw threaded rod having an end thrust bearing at its rear end on the main frame, a nonrofatable nut threaded on said rod and movable thereon to rotate the same by up or down movement of the lifting frame, and means for normally holdingfsaid rod against rotation in a direction to permit descent ofthe lifting frame, While permitting it torotate in the opposite direction.

2Q. In a lift truck, the combination with main and liftingframes and a steering handle, of means operable by said steering handle to Vlift the lifting frame comprising a rocking member mounted on the main frame, a lifting lever fulcrumed to swing concentrically Withthe axis of said rocking-member and connected with said steering handle to be actuated thereby, pawl and ratchet mechanism operatively connecting said lifting lever and said rocking member for rocking the same to lift the lifting frame, lifting means connecting said rocking member With the lifting frame, means for normally holding the lifting frame against descent comprising members movable longitudinally relatively to each other by the rocking of said rocking member in either direction, and releasable ratchet means for normally holding said members against relative longitudinal movement in a direction to permit the descent of the lifting frame.

2l. In a lift truck, the combination With main and lifting frames and a steering handle, of means operable by said steering handle to lift the lifting frame comprising a rockin'r member mounted on the main frame, a lifting lever fulcrumed to swing concenrically With the axis of said rocking member and connected With said steering handle to be actuated thereby, pawl and ratchet mechanism operatively connecting said lifting le` ver and said rocking member for rocking the same to lift the lifting frame, lifting means connecting said rocking member with the lifting frame, and means for normally holding the lifting frame against descent` comprising telescopically associated members in the form of a cylinder, a screwthreaded holding rod movable longitudinally in said cylinder, and a fixed nut in said cylinder threaded on said rod, one of said members being connected with said rocking member to be moved longitudinally by the rocl'- ing thereof, and the other having a thrust bearing on the main frame, and means for normally holding said rod from rotation in one direction with respect to said nut.

22. In a lift truck, the combination with main and lifting` frames and a steering handle, of means operable by said steering handle to lift the lifting frame comprising a rocking member mounted on the main frame, a lifting .lever fulcrumed to swing concentrically with the axis of said rocking member and connected with said steering handle to be actuated thereby, paWl and ratchet mechanism operatively connecting said liftingl lever and said rocking member for rocking the same to lift the lifting frame, lifting means connecting said rocking member with the lifting` frame, and means for normally holding the lifting frame against descent comprising telescopically associated members in the form of a cylinder, a screwthreaded holding rod movable longitudinally in said cylinder, and a fixed nut in said cylinder threaded on said rod, said cylinder bein g connected with said rocking member to be moved longitudinally by the rocking thereof and said rod having a thrust bearing on the main frame, and means on the main frame for normally holding said rod against rotation in a direction to permit descent of the lifting frame.

23. ln a lift truck, the combination with main and lifting frames and a steering handle, of means operable by said steering handle to lift the lifting frame comprising a rocking member mounted on the main frame, a lifting lever fulcrumed to swing concentrically With the axis of said rocking member and connected With said steering handle to be actuated thereby, pawl and ratchet mechanism operatively connecting said lifting lever and said rocking member for rocking the same to lift the lifting frame, lifting means connecting said rocking member With the lifting frame, means for normally holding the lifting frame against descent comprising telescopically associated members in the form of a cylinder, a screw-threaded holding rod movable longitudinally in said cylinder, and a fixed nut in said cylinder threaded on said rod, said cylinder being connected With said rocking member to be moved longitudinally by the rocking thereof and said rod having a thrust bearing on the main frame, ratchet mechanism supported by the main frame for normally holding` said red against rotation in a direction to permit descent of the lifting frame, and means operable to release said rod to permit such rotation thereof.

Q-f. ln a lift truck, the combination with main and lifting frames and a steering handle, of means operable by said steering handle to lift the lifting frame comprising a crank mounted on the main frame, a pitman connecting said crank with the lifting frame, a lifting lever fulcrumed to swing coaXially with said crank and connected with said steerin r handle to be actuated thereby, a ratchet member connected With said crank, a pawl carried by said lifting lever and engaging said ratchet member for actuating the same by the operation of said lever in one direction, means for normally holding said lifting lever against descent including cooperating rotatable and non-rotatable members interposed between said crank and the main frame, and having screw-threaded connection with each other arranged to effect rotation of said rotatable member by relative longitudinal movement of said members, ratchet mechanism for normally holding said rotatable member against rotation in a direction to permit descent of the lifting frame, and means operable to release the latter ratchet mechanism and to move said paWl out of engagement with said first mentioned ratchet member, to permit descent of the lifting frame.

25. In a lift truck, the combination With main and lifting frames and a steering handle, of means operable by said steering handle to lift the lifting frame comprising a crank mounted on the main frame, a pitman connecting said crank with the lifting frame, a lifting lever fulcrumed to swing coaXially with said crank and connected with said steering handle to be actuated thereby, a ratchet memberl connected with said crank, a pawl carried by said lifting lever and engaging said ratchet member for actuating the same by the operation of said lever in one direction, means for normally holding said lifting lever against descent including a screw-threaded holding rod having end thrust bearing on the main frame, a nonrotatable nut threaded on said rod and connected with said crank to be moved thereby longitudinally of the truck, a ratchet wheel mounted on said rod to rotate therewith, a pawl mounted on theV main frame andl cooperating with saidratchet wheel to normally hold said rod against rotation in a direction to permit descent of the lifting frame, and means operable to simultaneously move the latter pawl andV said first mentioned pawl out of operative position to permit descent of the lifting frame.

Q6. In a lift truck, the combination with main and lifting frames and a steering handle, of means operable by said steering handle to lift the lifting frame comprising a crank mounted on the main frame, a pitman connecting said crank with the lifting frame, a lifting lever fulcrumed to swing coaxially with said crank and connected with said steering handle to be actuated thereby, a ratchet member connectedV with said crank, a pawlV carried by said lifting lever and engaging said ratchet member for actuating the same by the operation ofsaid lever in one direction, means for normally holding said lifting lever against descent including a screw-threaded holding rod having end thrust bearing on the main frame, a'non-rotatablernut threaded on said rod and connected with said crank to be moved thereby longitudinally of the truck, a ratchet wheel mounted on said rod to rotate therewith, a pawl mounted on'the main frame and cooperating with saidratchet Wheel to normally hold said rod Vagainst rotation in aV direction to permit descent of the lifting frame, anti-frictionbearings for holding said rod against longitudinal movement in either Y ing said ratchet member for actuating the same by the operation of said lever in one direction, means for normally holding said'lifting lever against descent including a screwthreaded holding rod having end thrust bearing on the main frame, va non-rotatable nut threaded on said rod, a cylinder connecting said nut with said crank, a piston on said rod Y operating in said cylinder, a ratchet Wheel mounted on said rod to rotate therewith, a pawl mounted on the main frame and cooperating with said ratchet wheel to normally hold said rod against rotation in a direction to permit descent of the lifting frame, and means operable to simultaneously move the latter pawl and said first mentioned pawl out of operative position to permit descent of the lifting frame.

Y ARTHUR M. BARRETT.

27. In a lift truck, the .combination with i Y main and lifting framesand a steering handle, of means operable by said steering handle to lift the lifting frame comprising a crank mounted on the main frame, a pitman connecting said crank with the lifting frame, a lifting lever fulcrumed to swing coaXially with said crank and connected withV said steering handle to be actuated thereby, a ratchet member connected with said crank, a pawl carried by said lifting lever and engag-

Images