US1200408A - Accumulator. - Google Patents

Description

0. P. BUSHNELL.

ACCUMULATOR.

APPLICATION FILED APRA, :91s.

1,200,408. Patented oct. 3,1916.

Slap@ WWK m .L ik!" new from LWP/usanze acumulador n4: mmm: PETERS cm Pnomumm. wnsnmc wn. v. c.

Witwe/Aoco 0. P'. BUSHNELL.

ACCUMULATOR.

APPLICATION man APR.4.1916.

Patented 0015.3,1910

SHEETS-SHEET 2.

figav Ian/Pressure 0 P. BUSHNELL.

ACCUMULATOR. APPLICATION` FILED APR.4. 1916.

1 .200,408. Patented Oct. 3, 1916.

SHEETS-SHEET 3.

mr Nmuus Pneus co.. Fuer-041mm wasumc mn. n. cA

0. P. BUSHNELL.

ACCUMULATOR.

APPLICATION vFILED APR. 4, Isle.

Patented Oct. 3, 1916.

TSHEETS-SHEET 4.

www. 42;:

1N: Nmmes Parras ca.. Pnomvumn wAsmNu mv. n. c.

0. P. BUSHNELL.

ACCUMULATOH.

APPLICATION FILED APR. 4. 1916.

1,200,408. 1 Patented ont. 3,1916.

:r I SHEETS-SHEET 5.

tto@ ncaa mr nomas Psrsns cu., Puomunw.. asuma von. a c.

0. P. BUSHNELL.

ACCUMULATOR.

APPLlcATmN mmv Avn. 4. 191e.

3., m .Ml 0 M m\\\\@ M lum@ 311111215 To/z,

i mm H|||||||| mles/gs me Nvums uns ca. mmf C ma.. wAsnma nm. nv c.

0. P. BUSHNELL.

ACCUMULATOR.

Patented Oct. 3, 1916.

TSHEETS-SHEET 1.

IA. Si

OSCAR l. BUSHNELL, OF BELLEVILLE, NEW JERSEY.

ACCUMULATOR.

i ,ece-ies.

Application filed April 4, 1916. Serial N o. 88,978.

To all whom t may concern: y

Be it known that I, OSCAR P. BUsI-INELL, a resident of Belleville, in the county of EsseX and State of New Jersey, have invented certain new and useful A'Improvements in Accumulators, of which the following is a specilication.

In many branches of the industrial arts it is very desirable to vary the load on the accumulator plunger, and consequently the pressure delivered by the accumulator, beginning with the lowest pressure and increasing the load and consequent pressure as the work progresses. In the manufacture of paper board for example, it is objectionable to apply the full pressure all at once. To obtain the best results, it is the practice to apply the lightest pressure first to squeeze out a little water, and to allow that pressure to remain for a certain length of time, then to increase the load and consequent pressure to squeeze out a little more water, and to allow that pressure to remain for a certain length of time,'andl so on step by step, until the highestl desired pressure is reached. S0 far as I Aam informed,.however, hydraulic accu1nulators,vas heretofore made, are built to give but. one pressure, a pressure determined by the weight of the dead load piled upon or carried by the accumulator plunger itself. .Of course, by stopping the operation o f the accumulator and increasing or diminishing its load, the pressure can be correspondingly increased or diminished. But this, with the heavy weights which are employed, takes both time and trouble to accomplish, and as a rule is only practicable when the change is made not oftener than once or twice a day; and even that is not infrequently too often to handle the heavy material of which the load is made up.v For the purpose'of obviating these and other objections, I have produced what may be termed a variableload accumulator, in which the increase in the load and consequent pressure is effected automatically at predetermined intervals and without stopping the operation of the accumulator, from the lowest pressure to the highest pressure desired, through any intermediate pressures desired. This I believe to be broadly new with me.

Specification of Letters Patent.

Patented Oct. 3, 1916.

To enable others skilled in the art to understand and use'my invention, I will now proceed to describe kthe manner in which the same is or may be carried into effect by reference to the accompanying drawings Y which represent a .hydraulic accumulator embodying my invention in its preferred form.

In said drawings-Figure l is a plan view, largely diagrammatic, showing the pump (a quadruple high-pressure pump),

and forty feet high, so that necessarily certain intermediate portions of the structure have been broken p away and removed, in order to bring the figure, even at the reduced scale on which it is drawn, within the limits of the sheet.v Fig. 5 is an enlarged section on line 5 5 Fig. 4 of the structural steel uprights which form the guides between which the accumulator plunger and weights move, and to which the bearings and supports for the mechanism for regulating the movements of the accumulator plunger and its associated parts are attached. In this view the pawl shaft 29 and trip shaft 40 are shown in horizontal section with one of the pawl-holders 30 and pawls 3l partly in section, and withy the trips 39 in plan, showing their staggered arrangement on the trip shaft 40.V The view also. shows in plan the staggered arrangement of the peripheral lugs 27 on the intermediate weightsection supports 24,' and the rods 28 passing through and connected to said lugs, whereby each intermedia-te weight-section support is suspended from the one next above; `the same arrangement of the parts last named is shown in elevation on reduced scale in Fig. 3. kThe same is partially shown in elevation on larger scale in Fig. 4, together with the timing mechanism and the pawl and trip shafts. Figs. 6, 7 and 8 are-detail views on enlarged scale of the timing mechanism. Fig. 6 is a sectional elevation of said mechanism on enlarged scale with the clutch lock 53 lifted out of engagement with the clutch disk 52. Fig. 7 is a section online 7-7 Fig. 6. Fig. S is a detached el'evation of the clutch disk 52 with the clutch lock 53 dropped into engagement therewith. Figs. 9,-13 inclusive, have to do more particularly with the mechanisms for operating the safety or relief valve l5, and show on a like enlarged scale the structural details of the same. Fig. 9 is a. sectional pla-n, showing one of the steel I-beam upright-s 2, with a portion of the bottom' weight support 1, together with one of the pawl holders 30, and pawls 31, and oneV of the trips 3Q-the parts last named being shown in full lines in the position ,they occupy when thel pawl 31 overhangs the tang T on the bottom weight support 1, and in. dotted lines inthe position which they occupy when the trip 39 in its revolution has engaged the pawl holder 30 and has swung it far enough around to carry the pawl 31 out of the path of the tang T. Fig. 10 isa side elevation of these parts, with the pawl holder 30 and centering eollar 34, partly broken awa-y to expose interior structural details. In `this figure the bottom weight support 1 is shown in dotted lines as just passing the pawll 31, during its descent from its highest position tothe low position from which it originally started, and the pawl is shown in dotted lines in tilted position to permit of this descending movement of the bottom weight support 1. Fig. 11 isV an elevation of the pawl shaft with one of the pawl holders (with pawl removed) partly in section, the parts being in the position they occupy when the safety valve 15 is in closedposition. Fig. 12 is a similar view with the parts in the position they occupy when the safety valve is lifted and the pawl holder has been swung to one side so that its pawl (not shown)v will be just on the point of disengaging from the tang T on the bottom weight support. Fig.

13 is an enlarged diagram showing the centering collar 34 in elevation, and the path of the pawl holder in rising from its seat in the centering collar, thence swinging to one side to clear the bottom weight support 1, and thence dropping back into its seat to which it is directed by the converging inclines 35 of the centeringcollar. n

In the diagrammatic Fig. 1, 1 is the bottom weight support, which in practice is `connected to and moves with the accumulator plunger crosshead (not sli-own)` between the structural steel upri'ghts 2l of I cross section; 3 is the accumulator cylinder and 4 is the plunger; 5 is the quadruple high pressure pump drawing its supply from tank 6 through pipe 7 and discharging it into the accumulator cylinder through pipe 8 and its connections 9, 10; 11 is the pipe through which pressure from the aceumlator is conveyed to the press where it is t0 be utilized; 12 is a check valve in pipe 9 which opens to the pump pressure but closes against back pressure from the accumulator; a cock 13 in pipe 11 controls a discharge 13a leading back to the tank- 6; from pipe 10 leads a pipe 14 back to the water supply tank 6, said pipe having in it a safety7 or relief valve, 15, operated and controlled by means hereinafter described, and normally closed against either accumulator pressure or pump pressure, but which when opened will permit circulation both from pump and accumulator through the pipe 14 back to the tank, thus, preventing any further increase in pressure, and consequently any further rise of the accumulator plunger, so long as it is open. The pump gets its movement from any suitable prime mover, 16, 16a indicating the fast and loose pulleys to which a driving belt is led from the prime mover. As shown in Fig. 3*, the fast one 16, of these pulleys has on its hub a pinion 17 which meshes with a gear wheel 18 on crank shaft 19 from which the high pressure pump units 5 are driven.

The operating valve X and its co-nnections shown in Figs. 1, 2, 3, are designed mainly to connect the trip shaft with,

yand disconnect it from, the timing mechanism by which it is rotated, and will be hereinafter described in connection with the parts last named.

When the high pressure pump is in action it will act to lift the accumulator plunger until the safety or relief valve 15 is opened, when further increase of pressure, and consequent rise of the plunger, is prevented, although the pump still continues in action. The moment the valve 15 closes, the accumulator plunger will again take up its upward movement, and thus, without shutting down the pump, the upward movement of the plunger and weight or weights carried by the same, can be stopped andy resumed at will.

This much by way of general explanation. I shall now proce-cd to describe more particularly the construction and arrangement of the frame and the operating parts of the accumulator, and especially those parts by which the operation of the safety valve is automatically controlled, and by which the plunger at each upward stage of its movement at predetermined `intervals of time is caused to auto matica-lly piek up additional weight as required.

3 is the vertical accumulator' cylinder,

mounted in or on, and supported by, a suitable base structure; 4 is the plunger which works up and down in the same. The cylinder is of course provided at the top with the customary stuing box to make a tight joint with the plunger which works through it. To the top of the plunger is secured the crosshead 20, the ends of which fit in the channels of the uprights 2 which constitute guides for assuring the crosshead in its up and down movements. The uprights are held and supported in proper position by a skeleton tower-like structure 21, wherein they are properly secured. Connected to and moving with the crosshead is the lowermost or bottom weight support 1, shown on enlarged scale in Fig. 1, having peripheral guide fins 2v2, which enter and move in the guide channels in the interior opposite faces of the two uprights 2. The connection between the crosshead and bottom weight support consists of four vertical rods 23 which extend between, and pass through holes in, thecrosshead and bottom weight support respectively, and are there held by nuts on their projecting screw-threaded ends.

Above the bottom weight support is a series of weight-section supports, as they may be called, 24, located one above the other at proper intervals apart, and each designed to receive an individual unit or section of the whole load. These weightsection supports, however, while provided,

like the bottom weight support, with peripheral guide fins tolit in the channels of the uprights between which they are designed to move, are not connected, like the bottom weight support, to the plunger crosshead, but the topmost weight section support 24 is suspended from brackets 25 secured to the uprights 2 by four rods 26 which pass through suitable holes in the brackets and in peripheral lugs or projections 27 on the suction support respectively, and are there held by nuts on their screw-threaded ends as shown. The intermediate weight-section supports-that is to say, those between the topmost support 24, and the-bottom weight support 1--are suspended, each from the section support next above, by rods 28 applied and arranged similarly to those al ready described, each weight-section support 24 having two sets of holes-four in each setformed in peripheral lugs 27 suitably placed or staggered so that the rods, when nested as hereinafter described, will not interfere with one another, as indicated in Fig. S-the one set of holes being for the rods 28 by which it is suspended from the weight-section support next above, the other being for the rods 28 from which is suspended the weight-section support next below. The eyes or holes which receive the rods by which the support is suspended fit the rods loosely to an extent which will permit the support Vto move up and down on the rods. The distance between any adjoining two of the weight-section supports will be determined by the length of the rods which will connect them.

I have shown on one or two of the weightsection supports 24 a load composed of removable weights IV, which are made sectional, so that they may be piled up on the support without interfering' with the rods 23 which connect theplunger crosshead and the bottom weight support 1, and which, of course, will pass up loosely through -the intermediate weight-section supports 24. Under this arrangement it will be seen that as the accumulator plunger is forced upward by the pressure in its cylinder, it -will carry with it the bottom weight support 1, which as it rises will pick up in succession each weight-section support 24, and the individual weight-section unit WT which it carries, the intervals of time between the picking up of successive section-weight supports 24, and the consequent increase in the load, depending upon the rate of upward movement of the plunger, and the length of the rods 28 which connect a given supthe mechanism by which the movement of the accumulator plunger for this purpose is governed and controlled.

Supported in suitable bearings attached to one of the uprights 2 is a vertical shaft 29, attached at its lower end to the stem of the safety valve 15 (shown in section in enlarged Figs. 11, 12). The shaft 29, which I shall call the pawl shaft, is capable of vertical movement in its bearings of suf ficient range to permit it to lift the safety valve far enough to open the port in the pipe 14 (F ig. 1) which it controls. The means for thus lifting the pawl shaft conivprise a projecting tang T on the periphery of the bottom weight support 1, and a series of detent devices, each consisting of a pawl holder 30, and a pawl 31, pivoted in said holder on a horizontal axis 32-these parts with other parts associated therewith being shown on enlarged scale and in detail in Figs. 9-13.

The pawl holder is mounted loosely upon the pawl shaft 29 so that it may both swivel and move up and downron the same; and it is held in place thereon between the adjustable set collar 33 above, and the centering collar 84 below, which latter is formed with two downwardly converging inclines 35, which at their point of meeting furnish a seat for the pawl holder, said pawl holder being furnished at that point with a friction roller 36 which rests in the seat thus formed, as indicated in Fig. 11-this being the normal position of the pawl holder. i The distance between the collars 33 and 34, as

indicated inFigs.k 11 and 12, is sufficiently greater than the height of the pawl holder to' furnish clearance to permit the latter to bel lifted high enough to clear theV top of the centering collar 34 by the time' it contacts with the set collar above at which point it can swivel or swingv upon its shaft 29 without being interfered with by the centering collar 34., The swiveling of the pawl holder permits it to be swung around to carry its pawl 31 out of engagement with the tang T ;y and, after being thus released, it drops back to its seat in the centering collar, bein'g guided to proper place by the passage of its roller 36v over the converging inclines 85..

The nose of the pawl 31, which is armed with a friction roller 37, normally overhangs and lies in the path of movement of the tang T of the bottom Weight support 1, so that when the latter rises said tang will meet friction roller 37 in the nose of the pawl-this friction roller 37 serving to facilitate the swinging movement of the pawl b v which it is disengaged from the tang T. A. series of these pawls and their holders l are thus-mounted` and held upon the pawl shaft, one above the other, in number corresponding to the number of increased pressures to be delivered by the accumulator; and normally the noses of the pawls are in one and the same vertical line, so that, as the bottom weight support 1 rises, its tang T will meet the several pawls in succession. 1n the normal position of thel pawl its weighted heel rests upon a-ledge 38 in the pawl holder, which enables the pawl to take and sustain, without tilting, the upward thrust of the tang T as the latter rises.

Thus when the tang. in its upward move' ment reaches and contacts vwith the pawl, it will lift the pawl and pawl holder bodily thro-ugh the clearance space above until the pawl' holder brings up against the upper set collar 33 on the pawl shaft 29, after which continued upward movement ofthe tang T will, through the intermediary of the pawl and` pawl holder, lift the pawl shaft 29 with the effect of opening the safety or relief valve 15, which, as hereinbefore stated, arrests further upward movement of the accumulator plunger and the bottom weight support 1 attached to the same, and permits the pressure thus far accumulated tol be made use of. The horizontal dotted lines fr, y, e, between the upper parts of Figs. 11 and 12,- indicatev diagrammatically this upward movement of the pawl holder, the distance between and g/ representing the clearance to be traveled by the pawl holder in rising from its position in Fig. 11 to the set collar 33, and the distancev between y and c representing. the subsequent extent of movementl of the pawl holder by which the pawl shaft is lifted to open the valve 15. f

To permit the upward movement of the plunger and its attached bottom weight su-pport to be automaticallyv resumed at the proper time with the consequent taking on of additional weight, I make use of a series of trips 39, one for each pawl holder, mounted iXedly but adjustably upon a vertical rotating shaft 40-the trip shaftwhich is mounted and supported in suitable bearings and arranged parallel with the pawl shaft 29. Each trip revolves with the shaft 40 and is secured thereon in such position as, during its rotary movement, to meet at the proper time its appropriate pawl holder 30 and to swing it to one side far enough to cause its pawl 3l to clear and disengage4 itself from the tang T, as indicated by dotted lines in Fig. 9. The pawl holder is formed for this purpose with an arm 41 which extends into the path of rotation of the trip 39, and at the point where it meets the trip, is provided with a roller 42 to reduce friction.

As soon as pawl 31 swings aside far enough to clear tang T, the pawl shaft at once drops, thus -closing the safety valve, and again delivers the pump pressure to the accumulator with the effect of causing bot tom weight support 1 to resume its upward movement until its tang T brings up against the pawl next above, when the operation just described is repeated, and so on. The

pawl shaft in dropping to close the safety' vvalve of course carries with it the pawl and pawl holder thus disengaged from the tang T. After the shaft has come to rest, however, the descending movement of the pawl andl pawl holder will still continue, independently of the shaft, through the clearance yspace-which at this time is between the pawl holder and the centering collar 34 below, as indicated in Fig. 12-until the pawl holder brings up in its seat in the said collar, to which seat it is directed during this descending movement by the converging inclines 35. The course of the pawl holder in thus rising from and returning to its seat, is indicated diagrammatically by the arrows in Fig. 18.

The rotary movement of the trip shaft is obtained from what I term a timing mechanism, which is designed to drive said shaft at a measured and very slow rate of rotation. The parts of this mechanism are mounted in a bracket frame 43 secured in proper position to one of the l-beam uprights of the main frame, said bracket frame also containing the upper trip shaft sleevelike holder or bearing 44, up through which the trip shaft extends, as shown in Fig. 6. Supported in suitable bearings in frame 43 is a horizontal worm shaft 45 driven by any suitable means-in this instance getting its movement from the wheel 18 on the crank shaft 19 by which the pump units are driven, as indicated in Fig. 3, through the intermediary of a belt 46 passing from a pulley 47 on the hub of wheel 18 to a pulley 48 on the outer end of the worm shaft 45. Worm shaft 45 gears with and drives a worm gear 49 mounted in proper bearings in bracket frame 48 and having on its hub a worm 50 which in turn meshes with and drives a properly mounted worm vgear 51 revolving loosely upon the trip shaft 40 which passes aXially up through it.

Connection is made between the worm gear 51 and the trip shaft by means of a clutch mechanism consisting of a clutch disk 52 keyed on thetrip shaft and located between the trip shaft holder or bearing 44 and the slowly revolving power driven worm gear'51-said clutch disk having an annular ratchet-formed upper face, as shown in Figs. 7, 8. To coperate with the clutch disk I provide a clutch lock or grab 53, thev cylindrical stem of which passes down through a similarly formed eccentrically located opening in the worm gear 51, in which opening the clutch lock or grab, while revolving with the gear can slideup and down away from and toward theA ratchet toothed face of the clutch disk below. I/Vhen lowered, its toothed lower end engages the clutch disk, therebycausing the trip shaft to revolve in unison with the worm gear 51; when raised, it will be lifted out of engagement with the clutch disk, whereupon the rotary movement of the trip shaft will cease. Any suitable means for thus manipulating the clutch lock 4may be employed. In the arrangement for the purpose shown in the drawing, the stem of the clutch lock is secured to a cap 54-a clutch lock cap-which fits over and down upon the upper en d of the trip shaft 40, on which it can both swivel and move up and down.

' The clutch lock cap 54 is swiveled upon the lower end of a vertical eye-bolt 55 attached to and suspended from one end of a rope 56 which passes over suitable guide pulleys 57 to a weight 58 which draws the rope in a direction to lift the clutch lock cap and consequently raise the clutch lock or grab 53 out of engagement with the clutch disk 52, in which position the parts are shown in Fig. 6. On the other hand if the weight 58 be lifted to give sufcient slack to the rope, the clutch lock cap, and consequently its attached clutch lock 53, will drop far enough to engage the latter with the clutch disk, in which position the clutch lock is shown in Fig. 8. For the purpose of thus manipulating the weight 58, various means may be employed. One convenient means for the purpose is shown in the drawing. The weight 58 is mounted upon a plunger'59 adapted to work up and down in a cylinder 60 connected by suitable piping as shown with some source of supply of water under pressure-a low pressure accumulator for instance; the iiow of water from the source of supply to the cylinder 60 is controlled by a valve 61 in X, shown in section in Fig. 2. In the position in which the operating handle 62 is there shown, connection of the cylinder 60 with the source of supply (inlet) is cut off by the valve 61. Throwing the handle from this position to the left will put the valve in position to place the cylinder and inlet ports into communication with the effect of lifting the plunger 59 and consequently the weight 58; throwing the handle from this position tothe right will put the cylinder and discharge ports into communication, thus allowing the plunger 59, and consequently the weight 58, to descend. The movement of the plunger downward, or in a direction to cause the clutch lock to be disengaged from the clutch disk 52, will also, through suitable intermediary mechanism (as indicated diagrammatically at 63 in Fig. 1), actuate a belt shifter S to shift the driving belt from the fast pulley 16 to the loose pulley 16a, thus stopping the pump 5, and also the timing mechanism.

It is desirable that after the conclusion of the operation the trip shaft shall be returned automatically to its original position. To this end (as shown in Fig. 3) a weight 64 is suspended from a rope 65 which passes up over a properly housed peripherally grooved guide pulley 66 to .a sheave 67 mounted on and fast to the trip shaft 40, to the periphery of which sheave it is secured. Under this arrangement, when the trip shaft is engaged with and rotated by the timing mechanism, the rope 65 will be wound up on the sheave which revolves of course with the trip shaft. When, however, the trip shaft has completed its work and is disengaged from the timing mechanism, the weight 64, acting through the rope 65 and the sheave 67 upon which the rope has been wound, will rotate the trip shaft in the opposite direction and return it to its original position.

The highest pressure is delivered when the tangAI of the bottom weight support 1 reaches the topmost pawl 81, and through its agency and that of its holder 30 lifts the pawl shaft 29 and opens the safety or relief valve 15, thus arresting the further upward movement of the accumulator plunger. It will be noted, however, by reference to Fig. 4, that there is, on the trip shaft, no trip 39 to coperate with this topmost pawl holder and pawl; and therefore the bottom weight support 1, and its superimposed load,

will remain at this poi-nt and continue the delivery of the final and highest pressure to the press indefinitely, or until released by some means. It is for -this purpose that the manually operated discharge valve or cock 13 is provided, and this valve or cock is preferably located in the immediate vicinity of the press, as shown, so that it may be conveniently reached and manipulated by the operator in charge of the press which, it may be said, is not infrequently located at quite a distance from the place where the accumulator and the high pressure pump are housed. This operator maintains' the highest pressure upon the material operated on in the press yfor such length of time as he mav deefm necessary; and then, the werk having been completed, he opens the discharge cock 13, thus relieving' the pressureand drawing off the water from the accumulator and the press and the system of piping connecting them, and r.eturn. ing it to the tank 6. rThis maintenance of the highest pressure is in no wise dependent upon the continued action of the pumps and timing mechanism, both of which (through the operating valve X and its ycon-` nections) ycan lbe stopped without affecting the continuance of the pressure in the interconnected accumulatorand press system, which, as hereinbefore explained, will be maintained until the attendant at the press station opens the valve 13,

AIt will be noted that there are but ,two manually operated valves in the whole system, the operating valve X at the accumulator and pump station, for stopping and starting the pumpand the timing mechanism, and the discharge cock 13 at the press station, to relieve the pressure in the accumulator and press system, and to drain the water from that system. It will also be noted that all of the intermediate pressures between the initial and the highest pressures are automatically controlled with precision and indeed absolute exactitude by the mechanism immediately associated with the accumula* torthat is to say, the timing mechanism and the pawl and trip systems. This is an important function ofthe accumulator.

The accumulator cylinder and the press cylinder, and their interconnecting system o'f piping, have a common communication with the pump, so that at all times during the operation of the pump the pressure is equalized throughoutthe accumulator and press system. The pump continues in operationlfrom start to finish, and the effect of opening the safety valve 15 at any predetermined intermediate point during the ascent of the plunger, is merely to arrest the movement of the plunger at that point, the excess water delivered by the pump beyond that required to maintain the pressure needed to hold the plunger at that point, returning through the bypass 14, and the now open safety valve 15 controlling the same, back to the tank 6.

The timing gearing may be so proportioned and have such initial speed, as to enable it to impart any predtermined speed of rotation to the trip shaft. In the actual timing mechanism, from which the representation in the drawing is taken, each one of the worm gears had 63 teeth, thus causing the second worm gear 51 to make one revolution for 63 63=3969 revolutions of the first worm shaft 4:5. These figures may be varied as desired, but the revolution of the trip shaft must in any event be veryslow, inasmuch as all the trips which are to act on Athe pawl shaft must do so during sub` stantially one revolution, at lthe outside, of the trip shaft-the trips being set each in the position required to enable it to reach and act upon its pawl holder at the proper time after the preceding trip has acted on its pawl holder. rI"he staggered arrangement -for this purpose of the trips upon the trip shaft, ,is indicated in plan-to some eX- tent diagrammaticallyfin Fig. 5.

In my variable load accumulator, as before remarked, the operations of stopping, restarting, taking on additional weight, again stopping, and so on, are automatically conducted and controlled. This I believe to be broadly new with me, beyond the particu-` lar vmechanism and devices herein shown and described by me for these purposes; although I prefer said mechanism and devices as being in practice the best adapted, on the whole, to effectuate my invention. I remark also that I am not aware of any hy.

draulic pressure accumulator, prior to mine,l

inwhich .there is any provision which would permit a plurality of weight sections to be automatically picked up, each in turn, by and during the ascent of the plunger, and then, during the descent of the plunger, to be automatically returned and dropped, one by one, into the respective positions from which they were originally taken. term weight-section I of course intend a weight-section' support 24, along with the individual initial load W, whatever it may be, that is associated with it. In conclusion, therefore, I would state y.that I do not confine myself strictly to the structural embodiment of my improvements as hereinbefore described and illustrated in the drawings, since manifestly the same can be varied considerably without departure from the spirit of my invention: but

hat I claim herein as new and desire to secure by Letters Patent, is as follows:

1. An accumulator comprising a cylinder; a plunger adapted to work up and down therein; a bottom weight support connected By the to and moving with the plunger; a plurality of weight-sections located, one over the other, above, and in the path of movement of, the bottom weight support; means for suspending each weight-section from the one neXt above, and permitting movement of the thus-suspended weight-section to and from the weight-section above; and a stationary support from which the topmost weight-section is suspended-these parts being combined and arranged for joint operation substantially as described, whereby said weight-sections will be automatically picked up, each in turn, by the bottom weight supportduring the ascent of the plunger, and then, during the subsequent descent of the plunger, will be automatically returned and dropped, one by one, into the respective positions from which they were originally taken.

2. rlhe combination with the accumulator cylinder and plunger, the bottom weight support connected to and moving with the plunger, and the plurality of weight-sections located, one over the other, above, and in the path of movement of, the bottom weight support, and arranged and adapted to be successively picked-up by said bottom weight support during the ascent of the plunger; of means for automatically ar,- resting the upward movement of the plunger after the taking-on of each additional weight-section; and means' for automatically, and at a predetermined time, releasing the thus-arrested plunger and permitting it to resume its ascent, substantially as and for the purposes hereinbefore set forth.

3. The combination with the accumulator cylinder and plunger, the bottom weight support connected to and moving with the plunger, and the plurality of weight-sections located, one over the other, above, and in the path of movement of, the bottom weight support, andarranged and adapted to be successively picled-up by said bottom weight support during the ascent of the plunger; of means for automatically arresting the upward movement of the plunger after the taking-on of each additional weight-section; means for automatically, and at a predetermined time, releasing the thus-arrested plunger and permitting it to resume its ascent; and manually operated means for relieving the pressure in the accumulator cylinder after the plunger has completed its ascent, and permitting the latter and its attached bottom weight support, together with the weight-sections superimposed on the same, to descend to the positions fromy which they respectively started, substantially as and for the purposes hereinbefore set forth. 1

4. The combination of the accumulator cylinder and plunger; a crosshead attached to the plunger; a bottom weight support; rods connecting the plunger crosshead with the bottom weight support; a topmost weight-section support, and suspensory rods for the same attached to the machine frame; a plurality of weight-section supports intermediate the topmost weight-section support and the bottom weightsupport; rods whereby each intermediate weight-section support is suspended from the one next above; Vand vertical guide ways in the frame for said crosshead and supports, substantially as and for the purposes hereinbefore set forth.

5. The combination of the accumulator cylinder and plunger; the bottom weight support connected to and moving with the plunger and provided with a laterally projecting tang; the pumps and the supply pipe leading therefrom to said cylinder and having a waste or relief outlet; a normally closed safety or relief valve controlling said outlet, a vertical` pawl shaft suported in proper bearings in which it can be moved up and down, and connected to and adapt ed to operate said valve; a pawl holder mounted, and adapted to swivel, and to move up and down, on said shaft; a set collar and a centering collar fixed on the shaft and serving to limit said up and down movement of the pawl holder which is located between them; a pawl pivoted in said pawl holder with its nose in the path of the laterally projecting tang on the bottom weight support, adapted to resist the upward thrust of said tang, but to tilt downwardly out of the path of the tang when pressed on from above; a trip shaft and means for rotating the same at measured speed; and a trip Xed on and revolving with said trip shaft, and adapted at a predetermined time after the tang has engaged the pawl and lifted the pawl shaft, thus opening the relief valve and arresting further upward movement of the plunger, to meet the pawl holder and to swing it in a direction to disengage its pawl from the tang, thus permitting the pawl shaft to drop, the relief valve to close, and the plunger and bottom weight support to resume their upward movement, substantially as and for the purposes hereinbefore set forth.

G. In an accumulator of the character described, the combination with the vertical pawl shaft and series of pawl holders and their contained pawls mounted thereon; of the trip shaft supported in proper bearings in a position parallel with and in proximity to the pawl shaft; a series of trips mounted thereon, each adapted to cooperate with its appropriate pawl holder on the pawl shaft; driving mechanism for rotating the trip shaft at measured speed; and means for engaging said driving mechanism with, or disengaging it from, the trip shaft at will.

7 In ,an accumulator of the character ldescribed, the combination with the vertical pawl shaft and series o pawl holders and their contained pawls mounted thereon; of the trip shaft supported in proper hearings in a position parallel with and in proximity to the pawl shaft; a series of trips mounted thereon, each adapted to coperate with its appropriate paWl holder on the paWl shaft;

E0 driving mechanism for rotating the trip shaft at measured speed; means for engagingl said driving mechanism with, or disengaging it from, the trip shaft at will; and means whereby the .trip shaft, when disengaged from its driving mechanism, is automatically returned to the position from which it started its rotary movement.

In ltestimony whereof I ax my signature.

OSCAR P. BUSHNELL.

Copies of this ,patent may be obtained :for jive cents each, by addressing the Commissioner of Patents,

Washington, D. C.

Images