US2121833A - Draft gear - Google Patents

Description

June 28, 1938. D. F. SPROUL DRAFT GEAR heats-Sheet l Filed Jan. 4, 1954 I I lll/ r I l I l l l I ll g i jo June 28, 1938.

Filed Jan. 4, 1934 3 Sheets-Sheet 2 mm mm MN Q RN M aw 9 m mm b y 3 7 7 %7/ w/7 i V X June 28, 1938. I D/F. SPRVOUL DRAFT GEAR s sheets-sheet '3 Filed Jan. 4, 1934 amid] Patented June 28, 1938 UNITED STATES PATENT OFFICE.

DRAFT GEAR Donald'F. Sproul, Chicago, Ill., assignor to Cardwell-Westinghouse Company, a corporation of Delaware v Application January 4, 1934, Serial No. 705,25

11 Claims- (Cl. 21333) I Supported between the draft and buffer lugs is 1 This invention relates todraft gears. for rail way cars and the like, and more particularly to the friction type of draft gear.

One of the objects of the invention is the provision of a new and improveddraft gear provided with novel means for retaining the movable parts of the gear in proper alignment during the operation of the gear.

'Anotherobject-of the invention is the provision of a new and improved draft gear provided with novel means for releasing the wedging mechanism during the initial release movement.

A still further object of the invention is the provision of a new and improved casing for a draft gear that is'provided with novel means for strengthening orreinfor'cingthe casing and for positioning the spring elements therein.

A further object of the invention is the provision of new and improved means for temporarily '2'0' shortening the length of the gear and which is automatically removed upon the initial use of the gear.

Another object or the invention is the provision of a new and improveddraft gear that is prompt in release, eifective and efiicient in operation, inexpensive'to manufacture, simple in construction, relatively easy to assemble and 'whenassembled difficult to disassemble and'which is not likely to become broken or get outof-repair. 3O- Other and further objects 'and'advanta'g'es of the invention will appear from the following'description, taken in connection with the accompanying drawings, in which:

' Fig. 1 is a horizontal section of the center sills 35 ofa railway car showing the invention in position thereon,.also in horizontal section;

Fig. 2 is a section on the line'22 of Fig. 1; Fig. 3 is an end elevation of a shock absorber; Fig. 4 is a section on theline 4-4 of Fig. 1; 5 is aperspectiveview of the casing; a 6 is' a' perspective view of the central or thrust wedgeg Fig. 7 is a perspective-view of the outer spring seat; i f

515 v Fig. 8 is a perspective view of the inner spring s t; a

Fig. 9 -is a perspective view of one of the friction shoes; and

.Fig. 10 is a perspective view of one of the fric-' tion plate groups.

56 in such constructions. 1

- the gear.

a pear.

' '---Referrin;gihow -to-- the drawings, thereference charactersflfland ll designate-the center sills of I airailway-carfh'aving the buffing' lugs I2 and l3 and'the draft lugs-I4 and i5 thereon, as is usual inserted between the, draft lugs l4 and I5 and the draft gear l6.

The casing I1 is provided with one or more external ribs extending longitudinally thereof for reinforcing the casing. As shown, each side of the gear is provided with two external ribs 2! and 22, respectively, and with the reinforcing ribs 23 and 24 adjacent to the forward end which extend transversely to the ribs 2| and 22. Additional ribs 38 reinforce the corners of the casing.

In order to furtherstrengthen the casing so, that the same maytake the overload without distortion, the inner surface of the casing is also provided with ribs extending longitudinally of As shown, each of the side walls of the gear is provided with reinforcing ribs 25'and 26 which will project inwardly from the walls of the casing and extend longitudinally of said casing. These ribs, if desired maybe arranged op- The top wall 21 and-the bottom'wall 28 of the 1 casing are each provided with reinforcing ribs 29 and 3| which extend longitudinally of the gear and have their inner edges cut away on the arc of I a circle for providing clearance for the springs and'for positioning the same, as will presently For convenience of description, the closed end of the gear will be referred to as the rear end thereof. The forward end of the casing is open and the top andbottom walls are provided with ribs 33 and 34 extending transversely of the casing adjacent to the forward ends of the ribs 2 9 and 3|. The ribs 33 and 34 constitute shoulders for the stationary friction plates, as will presently appear. The ribs 33 extend only a short distance inwardly from each side so as to provide clearance for the springs which extend along the center line of the gear. I

The" rib'34. comprises the rib extensions 35 and 36 at each side of the central portion of the gear. These ribs merge at their" base and are cut away at the central portion to form curved surfaces 3'! and 38 to provide clearance for insertingthe springs in the casing during the assembling operation and to provide clear- I ance forthe central wedge or thrust member.

The forward end of the gear is also provided with retaining ribs 39 and 4! on each side wall. These ribs are spaced apart for receiving wear plates, as will presently appear.

Two groups of intercalated friction plates are arranged at each side of the gear. Each group comprises two sets of plates, one set of which is movable and the other stationary. As shown, each of the groups comprises the stationary or stationary friction plate 42, a wear plate 43 and a movable plate 4 The movable friction plates 4 extend normally forwardly of the casing I1 and are adapted to be engaged by the follower block Hi When the gear is compressed beyond a predetermined point. The stationary friction plate 42 is provided with projections 56 at each side thereof for engaging the ribs 33 and 35 on the top and bottom walls for preventing the plate from moving longitudinally of the gear in either direction. The wear plate 43 is also pro-- vided with projections 45 at each side thereof for engaging the shoulders 33 and 35, for preventing longitudinal movement of this plate. Each wear plate also engages the ribs 39 and ii at its forward and rear ends. The capacity of the gear may be varied by varying the angle of the stationary friction plate 42, as will presently appear.

The two groups of friction plates are adapted to be forced into frictional engagement with each other for resisting the compression of the gear by suitable wedge elements or wedge mechanism. In the form of construction shown, which is by way of example only, this mechanism comprises a central, or thrust, wedge member 46 (see Figs. 1 and 6) having a head 4?, a hollow body portion 48 and a tapered nose portion 49, and also that portion of housing 6-1 which has the inclined surfaces 56 and 51. The head i! is provided with rearwardly facing V- shaped or wedge surfaces 50 and 5| which are adapted to engage inclined faces 52 and 53 on wedge shoes 54 and 55 for forcing said shoes laterally outwardly into frictional engagement with the friction plates during the compression of the gear.

The wedge shoes 54 and 55'are provided at their rear ends with inclined surfaces 55 and 51 which are adapted to engage corresponding inclined surfaces 58 and 59 on a housing 64 formed on an outer spring seat 6!. These wedge shoes have plane friction surfaces on their outer sides for frictionally engaging the plates 42. If desired, the friction surfaces of the wedge shoes may be provided with wear resisting inserts 6D. The shoes are also provided with concave sur faces 62 and 63 intermediate their ends on their inner sides, thus affording clearance for the nose portion 39 of the central, or thrust, wedge member 45, as clearly shown in Fig. l of the drawings.

The spring seat BI is provided with a forward-1y extending hollow projection or housing 64 having a slot 65 in its front wall through which the release element 7! extends, as. will presently appear. This seat is also provided with laterally extending flanges $5. and 6! against which the movable friction plates 44 are adapted to seat. These flanges are provided with spring positioning lugs 5%2- The flanges fili and Bi terminate in proximity to the ribs 25 and 26 on the casing ll whereby the spring seat M is guided on its inward movement. The ends of the spring seat arecurved, as'at to corn gages the follower IS. The parts are assembled against the spring seat El at their forward ends.

It is desirable that there be a prompt release of the gear after compression. In the present invention, suitable means are provided for loosening the wedging mechanism when the pressure is released. In the. form of construction shown, a release element H is employed. The element has its forward end extending through the housing 64 and the slot therein and is provided with recesses H1 in which guide lugs 89 engage. It is also provided with a recess 12 in :which the nose portion 49 of the thrust wedge member is adapted to engage, as shown more clearly in Fig. 1 of the drawings.

An intermediate portion of the release element H is provided with a flange l3'extending about the same which constitutes a spring seat and against which a coil spring 74 is adapted to seat. The spring i4 is. arranged within a spring 69 and seats against the closed end of the gear. The flange 13 is located rearwardly of the spring seat 6i;

Proper means are provided for holding the various parts of the wedge mechanism in operative position during the compression of the gear. As shown, the release element H is employed for this purpose. The forward end of this element extends axially through the housing 64, and since the housing is of considerable depth, the marginal edges of the opening 65 and the opening through the base of the housing will guide the longitudinal movement of the release element "H and will prevent the angular movement or sk ewing of the spring seat 6! as it moves inwardly during the gear compression. The slot 65 is only sufficiently enlarged to provide clearance, and, if desired, the opening in the base of the housing may be provided with operation of the gear. Since the release element ii is held by the springs axially of the gear and since the spring seat 6| cannot move angularly relative to the release element ll the spring seat 6| will beheld in proper operative position.

Since there is but a small clearance between the springs and between the spring 68 and the ribs 29 and 3! and between the extension 'lfiand the spring E4, the release element "II is heldfrom angular movement and itin turn prevents skewing of the wedging'mechanism'. a

In the inoperative or normal position .of the gear parts, the central or thrust, wedge member 45 extends forwardly of the casing l1 beyond the forward ends of the movable plates 44 and enwith the springs under compression.

more rapidly than the central'wedge memberf46l For convenience-of assembly, the housing 64-, release'element 'H and theflcasing I! are pro-' vided. with openings'll, 18, 19 and 8| which may 1 be'rbrought into alignment by. compressing the said openings.

'& In order to facilitate the insertion of the springs. In assemblingthe gear, the springs are firstinserted, then the release element II and then the spring seat 6|, are inserted andthe springs compressed to bring ,the openings TI and 18 into register with the openings 19 and 8| of the casing, after whicha key is inserted through The stationary plates 42-, the thrust, or central, wedge 46', the wear plates 43, shoes 54 and 55, and the movable. plates 44 are then placed in position and the key' removed.-

The central, or thrust, wedge 46 is provided with 1 laterally extending shoulders 82 .and 83 that are adapted to engage the shouldersformed by ribs 34 for limiting the outward movement of said thrust, or central, wedge 46. 7

gear between the draft and buffer lugs, suitable means are provided for temporarily shortening the length of the,gear,said means being such as to automatically become non-operative upon using the gear. As shown, the shoulders 82 .and 83 are provided with forwardly extending projections '84 and 85'(see Figs. 2 and 6) which engage the ribs v34 for. limiting the expansion of "the gear;

These extensions are narrow and light, butEha'vesufficient strength to hold'the gear slightly short er than its normal lengthuntil'it 'is installed. A

few exp'ansionsof the gear will wear these projections away to permit normal expansion of the gear. They are designed solely to'temporarlly 5 shorten the over-all lengthof the gear in order to compensate for variations in the length of the draft gear pockets of various cars.

In the operation of the gear during its initial compression, the thrust, or central, wedge member 46 may be considered as being forced rearwardly by the follower l9. This rearward movement of the thrust wedge member 46 tends to move the shoes 54 and 55 vrearwardly with it, but

' the springs 68 and 691 resist this rearward moveshock; Furthermore, since the space between the plates 42 tapers'rearwardly, the shoes 54 and 55 will be forced laterally inwardly as they are advanced, thereby forcing the central wedging faces on the central wedge 46 and the wedging faces, on the housing 64 farther apartwith the result that the sprin'g seat' 6| moves -rearwa'rdly This added or differential movement'of the spring seat 6| will cause an increasing resistance to the rearward movement of the shoes and 55.

Since the springfseat is moved rearwardly at a greater speed than" the --central wedge member andshoes, it is evident that the springs 68 and r 69 are "compressed far more than if the plates 42' were not tapered. The greater the angle of the inclined faces of these plates 42, the greater will be the movement of the shoes toward each other and the more the springs 68 and 69 will be compressed "by a given rearward movement of the wedge member46. It will, therefore, be

seen that the capacity of the gear may be varied by changing the angle formed by the faces of the plates 42. I x Upon release :of the gear, the inner spring 14, which acts directly against the release element H, moves the same together with the central wedge member promptly forwardly and releases the wedging mechanism, whereupon the springs 66 and 69 return the plates to inoperative position. a V

- I claim as my invention:

1. In a draft, gear, a casing having an open end, a group of intercalatecl stationary and movable frictionplates at each side of said casing at its open end, means for fixing certain of said plates to'said casing, certain of said plates being tapered forwardly, means for forcing said plates laterally into frictional engagement, said means comprising a thrust wedge member having wedge faces thereon, a friction shoe at each side of said wedge'member in engagement with said groups of plates, saidshoes having inclined faces thereon at their rear ends and having inclined faces at their forward ends in engagement with said wedge faces, a spring seat in engagement with the rear ends of said movable plates, means on said spring clined faces at the rear end of said shoes, a release element in'engagement with said thrust Wedge member, and extending as a unitary structure through said seat and last-named means, resilient means for resisting the inward movement of 1 said spring seat, resilient means for resisting the inward movement of said thrust wedge member and means including engaging shoulders on said wedge member and casing for limiting the .out-

ward movement of said wedge member for limiting the outward movement of said spring seat, said movable plates extending forwardly beyond said casing and said thrust wedge'member. extending forwardly beyond'said movablewedges, when the gear is expanded.

r 2., In a draft gear, a casing having reinforcing and spring positioning ribs on its inner surface and reinforcing ribs on its. outer sides, all of said ribs extending longitudinally ofthe casing, the ribs on the exterior of saidcasing atthe sides thereof being opposite; corresponding ribs onthe interior and ribs extending transversely of said casing at the ends thereof for reinforcing the corners of said casing.

3. A spring seat comprising an elongated hollow portion provided with wedge faces 'on itsfree seat having wedging engagementwith the inend and having laterally extendingv flanges at its opposite end provided with spring retaining lugs on their faces opposite saidhollow portion, said hollow portion having aligned axial openings in its base and in the portion between said wedge faces throughwhich a release element is adapted to extend. I a 1 4. A draft gear comprising a casing, a plurality of friction plates Within said casing, a

plurality of friction plates movable longitudinally of said casing, a spring seat for resisting thev inward movement of said plates, a plurality of nested springs, wedge shoes having two sets of wedge surfaces movable longitudinally of said casing, a thrust wedge member for engaging one set of Wedge surfaces, said spring seat being provided with a hollow extension having wedge faces on its outer extremity for engaging the other set of wedge surfaces, a release element extending through said spring seat and engaging said wedge member, said release element having a shoulder and arm extension, a spring surrounding said extension and engaging said shoulder for resist?" ing the inward movement of said release element during the compression of said gear, said extension extending within said spring beyond a plurality of turns of said spring.

5. A' draft gear comprising a casing, friction plates. within said casing, wedge shoes within.

said casing, a spring seat having a base portion and a body portion provided with wedging 'faces for engaging said wedge shoes for forcing said plates into frictional engagement during the compression of said gear, coil springs certain of which engage said base portion for yieldingly resisting the compression of said gear and a release'member slidably engaging said body and base portions, and having an extension extending into one of said springs beyond a plurality of the coils thereof for preventing the skewing of said spring seats V 6. In a draft gear, a casing having one end open and having a follower integral with the other end, a plurality of intercalated friction plates at each side of said gear'ywedge mechanism for forcing said plates into frictional engagement including a spring seat, a spring, means for resisting the inward movement of said mechanism, certain parts of said mechanism extending outwardly of said casing and certain other parts extending axially of said gearinto said spring a substantial distance through a plurality of the turns thereof and adapted to engage said seat at widely separated points for preventing skewing of said seat, and means for holding said mechanism in operative position.

'7. In a draft gear, a spring seat member comprising a body portion having a V-shaped recess in its outer end for receiving the inner end of a,

thrust element, an axial extension of said body portion, said body portion having a spring seat integral therewith and extending around the same adjacent'said extension for constituting an abutment for a spring, said body portion proanism for forcing said plates into frictional engagement, ,means including a plurality of coaxial spiral springs for. resisting the inward movement of said seat and wedge mechanism, said springs being positioned in said casing by said ribs, and means having one end engaging certain parts of said wedge mechanism at a plurality of separated points and having its other,

end extending into said springs a substantial distance and through a plurality of the turns ear. 7

release member, a spring for engaging said release member for resisting its inward movement, means including an interlocking connection between said release and central wedge members for preventing skewing of said central wedge member, said central wedge member having lateral projections extending outwardly behind said shoulders, and deformable means on said lateral projections for engaging said shoulders for'temporarily preventing the normal expansion of said gear Without interfering with its operation as a shock absorber.

10.- In a draft gear, a casing, a plurality of friction elements within said casing, a wedge member eng'agingsaid elements for forcing'the same into frictional engagement with one another when said gear is compresseda spring seat for engaging certain of said elements, resilient means engaging said seat for resisting the inward movement of said seat, a release member extending through said seat and engaging the inner end portion of said wedge member, said releasamember having an extension provided w'ith' a 'shoulder, a spring engaging said shoulder, and having'a plurality of turns extending about said extension for releasing said wedge member on the release of said gear and for holds 7 ing said extension in alinernent with said wedge member, said release; member extending axially through said spring seat for preventing the same from skewing'during the operation of said i gear.

11; A draft gear comprising a casing, a plurality of intercalated friction plates within said casing at each side thereof, certain of said plates being tapered forwardly, means on said casing for preventing certainof said plates from longitudinal; movement therein and the remaining plates beingmovable longitudinally of said casing and extending forwardly beyondthe end' thereof, means; including a central wedge member, at opposite endsof said plates for compress- 'ingthe latter upon compression of the gear, said wedge member being independently movable for compressing said plates laterally into frictional engagement, spring means for resisting the compression of said gear, easily deformable means rigid with one of said second-named means for engaging shoulders on said casing for limiting the outward movement of the wedge member during theinitial operation of the gear only, and

means independent of said spring means for positively releasing one of said central wedge members upon the release of the compressive force on said DONALl) F. SPROUL.

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