US1672281A

US1672281A - Lifting jack

Info

Publication number: US1672281A
Application number: US734730A
Authority: US
Inventors: Timothy C Pomeroy; Carl E Johnson
Original assignee: JEREMIAH E MADDEN
Current assignee: JEREMIAH E MADDEN
Priority date: 1924-08-28
Filing date: 1924-08-28
Publication date: 1928-06-05
Anticipated expiration: 1945-06-05

Description

June 5 1928 T. c. POMEROY ET AL LIFTING JACK s 2 s s n O. O E m WE M L M w. www M E m o N n w. M y Mw. 2 www* .nbhvb m Nb wh wm,

bmw: m n wl m w w wm 5 m. \Pm nb Q m l .W

Patented June 5, 1928.

V A 1,612,2s1- UNITED STATES PATENT: oFFlCl..l

' 'rnuo'rrnr` c. romiinov, or MINNEAPOLIS, AND cannn JoHNsoN, or s'r. PAUL, MIN- NESOTA, assumons or oNEfrHIRn 'ro JEREMIAH E. MADDEN, or cnicaeo, ILLI- NOIS.

LIFTING JACK.

Application led August 28, 1924. Serial No. 734,730.

'I` his invention relates to new and useful lmprovements'in lifting Jacks such as are commonly employed for-lifting the wheels for lifting heavy loads such as a portion of a locomotive or railroad coach or car. The operating means of the jack preferably c onsists of a jointed handle having a relatively small vpump-rod reciprocally mounted .in a section thereof, which, when actuated, functions to move vthe fluid within the jack during the lifting operation thereof; The operating handle is preferably connected to the lifting head of the jack in order to simplify -ing and closing of y manipulationA of the 'oper' construction and to provide a simple and convenient means for actuating the valve mechanism mounted therein. The novel valve mechanism is soconstructed that, when the'handle of the jack is in folded inoperative position all of the valve ports will be closed to prevent leakage of oil from the jack when transported from place to place and, as soon as the handle is unfolded or extended, the valve ports opened so that the jack may be operated to lift a load. When it isdesired' to lower the jack, a slight oscillation or lowering of thevhandle will permit the .fluid to by- -pass from beneath the pistonthrough the head to the upper side thereof or into the hollow plunger, thereby causing the head and plunger to gradually descend or if desired the load may be held on the jack by slightly raising the handle to close the lay-pass.4 An air vent is provided in the head of the jack to facilitate pumping the fluid from and to the interior of the plunger, through the head to the under side of the plunger. The openthis vent is also controlled should the jack accidentally'or inadvertently be overloaded. Y l,

duty liftwill be automatically The object therefore of the invention is to provide an improved jack.

A further and more specific object of the.v

invention is .to provide a hydraulic jack of simple and inexpensive construction which may readily becarried from place toplace, and is capable of operation with a minimum amount of energy and at the same time will be positive and eiiicient in its performance.

Other objects of. thel invention will appearv 'from vthe following description and the accompanying drawing-s and will be pointed out in the annexed claims.

' In the drawings there is disclosed a structure designed to carry out 'the various objects of the invention but it`is to be understood that the invention is not confined to the exact features shown, as various changes may be made within the scope of the claims which t follow. y

In the drawings: y

Figure 1 is a verticalsectional view of the improved jack; Y

Figure 2 is a plan -view of Figure 1, showing the handle extended ,and partially in sec tion, and also showlng the jack with the lifting bracket removed;

Figure 3 is a horizontal sectional view on the line 3--3 of Figure 1 with the lifting bracket removed showing the preferred manner of connecting the operating handle to the head;

Figure 4 is a detail sectional view on the line 4-4 of Figure 3, showing the means provided for by-passin the fluid from beneath the plunger en to the upper side thereof as when lowering the plunger;

Figure 5 is a similar view on the line 5-5 of Figure 3, showing the air vent communie. eating with the upper portion of the plung- QI'.; .i

Figure 6 is an enlarged detail sectional view showing the preferred form of packing employed betweenthe upper end of the cylinder and the., plunger, and also showing the means provided for limiting the upward l movement of the plunger;

Fi ure 7 is a detail sectional view on the line -7 of Figure 2; 4

`Figure 8 is an enlarged detail sectional view on the line 8-8 of Figure 1;

- Fi ure-9 is a horizontal sectional view on the ine 9-9 of Fi` re '1, showing only the Vlifting head an the tapered valve u means such as the threads 22.

mounted therein, the valve being shown in the cylinder, and as shown in Figure 1 thev lower end of this sleeve is closed by means of a shouldered disc'or plate 14. A packing cup 15 of suitable material is seated against this plate and is tensionably held in'eontact with the walls of the cylinder by means of a .cup-shaped retaining member 16 mounted therein. A washer 17 is seated against the Vmember 16and this'washer is apertured to receive-the threaded ends of an intake tube 18 and a discharge tube 19, arranged in f spaced parallel relation lWithin the hollow plunger 13. The upper ends of thesetubes are secured to ya lifting head 21 by suitable The lifting head 21 is preferably provided. with an annular shoulder 23, adapted to be seated against the upper end of the hollow plunger 13. A threaded nut 24 is mounted on the lower end of the discharge tube 19 and a cap 25 onthe lower end of the intake tube 18, and when these two are tightened the head 21, plunger A13, retaining member 16, and the washer 17 will be securely clamped together for operation as a unit.

A feature of this invention resides in the novel means provided for limiting the vupward movement of the-plunger, and such means referably consists in the provision of a suitable stop-provided adjacent the upper end portion of the cylinder. As shown 1n Figure 1, a packing nut 26 is provided at the upper end of the cylinder and within this packing nut the usual packing 27 is pro- `vided. An annular ring or detent 28 is seated against the end of the cylinder beneath the packing 27 and this ring over-- hangs the bore ofthe cylinder and thereby functions to provide al limit stop. for the upward movement of the plunger. As shown in this figure, the major portion of the plunger 13 is preferably reduced in diameter in order to provide an annular shoulder 29 adjacent the lower end portion thereof. This shoulder isadapted to engage the stop ring 28 when the plunger reaches the limit of its upward movement as clearly shown in Figure 6. It will also be noted by referring to Figure 1 that means are provided for returning to the interior of the plunger 13 any oil which may-` pass by the packing cup 15 and enter the annular space around the plunger between the shoulder 29 and detent or stop ring 28, caused by the high pressure beneath the plunger when the jack is in op eration.y Such means preferably consists in providing a plurality of apertures 31 in the wall of the hollow plunger 13 slightly below the annular shoulder 29. grooves 32 in the outer wall of the plun er connect these apertures rwith the annu ar space around the plunger above the shoulder 29, so that any oil, which might leak by the packing cup 15 from beneath the plunger 'and enter the annular space will be bypassed through the grooves 32 and apertures 3l into the interior of the plunger asit ascends, therebyeliminating the objectionable feature of the oil leaking out of the cylinder when the jack is used for lifting extremely heavy loads, which is a common occurrence with hydraulic jacks of ordinary construction. This, therefore, is an importantfea- Small ducts or j ture of the invention as it practically renders the jack leak-proof.

As shown in Figure 1, the intake tube 18 is provided with an intake port 33l adjacent the lower end-portion thereof which is in communication, with the interior of the plunger 13. A valve 35 of'ordmary construction arranged therein, is provided in the lifting head 21, and this port connects the upper end of the intake tube 18 with a horizontal duct 36, having one end in communication with a similar upright port 37 which downwardl leads therefrom and is in connection wit the upper ,end of the discharge tube 19. A

vspring-actuated check valve 38 is mounted 1n the horizontal duct 36, and this valve functions to prevent the oil pumped into the tube 19', from flowing `back into the intake tube 18 when the jack is being operated to lift a load. Threaded

plugs

39 and 41 are mounted in the head 21 and function to .close the ends ofthe port 34 and duct 36,

port 34 having a ball check respectively in order to facilitate assembling of the

valves

35 and 38, mounted therein.

The means provided for by-passing the oil from beneath the plunger back into the interior of the plunger, in the operation of lowering the jack, preferably consists in the provision of a tapered valve plug 42 seated m a correspondingly tapered `bore 43 provided in a boss 40 Ipreferably lintegrally formed on one side of the lifting head'21 as shown in Figures 1 and 3; This valve plug 42 also functions as a means for piv' otally connecting to the jack, the vjack handle and pumping means, which will subsequently be described. i Referring to the 'l above figures` it will be noted that the horiannular groove 44 .provided in .the central- .portion of the'body of the tapered plug 42.

y -the tapered bore Lavamatv An aperture 45 is drilled through the plug in alinement with .the annular groove 44,

and this apertureis in communication with a conduit 46 provided shown in Figure 3. The other end of the conduit l46 terminates in a hub 47 which is preferably integrally formed 0n the plug and is arranged at right angles thereto. This hub is suitably threaded to receive one end of a tube or pipe 48' `comprising the intermediate section ofthe handle. The tapered plug 42 is yieldably retained in its tapered seat by means of a compression spring 49 coiled about the reduced end portion 5l thereof. has one end bearing against a w'asher 52 which is seated against the annular face 53 provided round the reduced end-portion of 43. The other'end of the spring is seated in a cap 54 which is prevented from outward movement upon the reduced end portion 51 ofthe plug by means of a pin 55. The reduced end portion 51 is preferably provided with a flattened surface 50as shown in Figure to prevent the cap 54 from rotating thereon. The cap 54 is of such length as to normally be out of engage- `ment with the face 53 and functions to provide a shield or.clo sure for the spring49 and washer 52 thereby to present a neater appearance to the jack. The cap, however, may also function as a means for limiting the axial movement of the plug 42, should the pressure within the conduit 46 and groove 44 become so high that it would tend to unseat the plug from its tapered seat,as will hereinafter be more fully described.

` Referring to Figure 9, it will be seen that the upright port 37 is in communication with a relatively smaller'port 56 by meansvof a duct 57. The port 56 has onelend leading to the tapered bore 43 of the tapered plug 42. Similarly, the port 34 is connected to the tapered bore '43 by means of a duct 58 and a port 59 as shown in Figure 10.

LThe ports

56 and 59 are preferably horizontally in spaced parallel relation in the arranged lifting head 2l as particularly shown in Figure 4. In order to facilitate construction the

ports

56 and 59 are preferably drilled from the outside of the lifting head and it is therefore necessary that their outer endsbe suitably sealed by such means as the threaded plugs 61. In order to establish communication betweenthe

ports

56 and 59, a notch or recess 62 is cut in one side.l of the tapered Yplug 42 in alinement with the two ports, and when the plug 42 ispositioned as shown in Figure 4, communication between the twoports will be cut off, the `notch 62 registering with the lower port 59 only. l/Vhen the jack is being operated to lift a load the tapered plug 42 will be positioned as shown'in Figure 4, and when it is de- A sired to lower the jack, the plug will be in the plug, as clearly This spring preferably i in the bpre o f the sleeve packing 69 is interposed, in the usual manrotated in its seat until the notch 62 is brought into registration with the two

ports

56 and 59 there y .permitting the oil to flow from the upright port 37 through the duct 57 ,port 56 and notch 62, port 59, duct 58, upright port 34, and through the intake pipe or tube 18 back to the interior of the plunger. By this simple valve mechanism, therefore, the operator will have complete control ofthe raising and lowering of the jack by simply rotating the plug42 in its seat.

Another feature of-this invention resides inthe novel means provided for pumping the oil from the interior of the vhollow plunger to beneath the plunger in-the lifting operation of the jack.l Such means prefer-v ably consists of'a reciprocating displacement pum mounted in a section of the handle, whic handle is preferably composedof two sections in order that it maybe conveniently foldedy for packing in a small place, and also for the convenience in operation.- This pump consists of a pump-rod 63 which is loosely fitted within a. hollow tube 64 as particularly shown in Figure 8. A knurled sleeve 65 is seycured to one end of the tube 64 by means of threads 66, and this sleeve is bored to receive a packing gland 67 which has'provided thereon a shoulder 68 adapted to be seated againsta complementary shoulder provided 65. A suitable ner, between the upper end of the stationary gland 67 and the lower end of a movable gland 71 mounted in the enlarged bore 72 of the sleeve as shown in Figure l. The upper end of the sleeve is provided witha reduced end portion 73 which is threaded to receive a nut 74. This nut functions to tightly force the movable gland 7 1 against the packing 69thereby tightly compressing the packing against the pumpv rodl 63 A lock-spring 7 5'is preferably interposed between'the vupper end of the reduced end portion 73 of the sleeve and the inner face of the'nut 74 andthis spring functions to lock the nut in adjusted position. An op-l erating handle or grip 76 is secured to the lupper end of the pump rod 63 to provide It will also be noted by referring :to

Figures l Vand`8 that the pump rod 63 is loosely fitted within the vtherefore does not. come m contact with the hollow tube 64 and lthe pump rod and the inner Wallof the tube allow the fluid to reely pass thereby.

64 and this space is normally filled with the oil orother fluid used in the operation of the jack. A vsmall head .-77 is preferably secured to the lower end of the rod 63, this head merely functioning to prevent the rod from being withdrawn from the tube 64. As shown in Figure 8, the head 77 is preferably flattened on opposite sides in order to As hereinbefore stated, the operating handle of this novel jack is preferably con-w structed inV two sections, the pump section and an intermediate section connecting the pump section to the Lifting head of th'e jack. The two handlesections are pivotally connected together by means'ofan oil-tight ljoint similar in construction to the tapered plug valve connecting the intermediate han-- dle section to the lifting head of the jack as shown in Figure 3. This joint preferably comprises a' body 78 having a tapered `bore 79 provided therein adapted to receive a correspondingly tapered plug 81 as shown in' Figure 2. The means provided for retainling the plug 81 in its seat is similar to, that shown and described Iwith reference to thetapered plug '42, and like parts will therefore be referred to by like numerals. Similar to'the plu 42, the plug 81is provided with an annu ar groove 82 which is preferably in alignment with the tube 64 of the pump section of the handle, which tube is sey cured to the body 78 of the joint by means of the threads 83. An aperture 84 is drilled ,through the plug 81 and this'aperture is'in vcommunication with a port 85 also provided in the plug and which port terminates in a right-angled boss 86 threaded to receive one end-of the pipe 48 comprising the intermediate handle'section. By thus constructing the handle'of two sections, the handle ma readily and conveniently be folded to 11e substantially arallel to the cylinder of the jack, there y permitting the jackto be packed away in` a small space, such for instance as the usual toolbox of an automobile or truck. When the jack is in use, the handle may be extended its full lengtl1,-ther eby permitting the operator to stand in an erect position when operating the jack, if he -de- A demountable lifting step 87 is preferably provided aud this step has formed thereon an undercutl flange 88 adapted 'to engage a similarundercut portion 89 of the lifting head 21 when positioned thereon as shown inyFigure 1. A lug -91 is also provided on the step 87 and this lug is adapted to engage the opposite side of the head 21, thereby to securely lock `,the step to the lift.-

ingA head 21 when the step 87'is being used to lift the load. When the step 87 is thus vwhen the oil is bein being used to lift a load, the lug 91 bearing against the side of the liftin head 21, will be under compression and t e upper portion 92 of the step will be under tension as a result of the undercut flange 88 engaging the undercut portion 89 of the head, thereby securely locking the step to'the lifting head of the jack. If desired, the lifting step 87 may be removed from the head of the jack by simply lifting the projecting lower end 87 thereof, and when thus removed the jack may be used without the vstep by placing the jack directly beneath the load and allowing the upper face of the head 21 to contact therewith. A filler plug 93 isl provided in the head 2l through which oil may be introduced into the interior of the hollow plunger 13. i

In the operation of hydraulic jacks, itis necessary that means be. provided whereby. air may be admitted to the interior of the 'oil chamber or reservoir in order that the pump mayproperly function without the danger of buildmg up avaculmior a high v pressure therein which would interfere with the operation of the jack and would tend to render it inoperative. Means are therefore provided 'in this novel jack whereby air maybe drawn into the hollow plunger 13 pumped therefrom into the cylinder 10 eneath the plunger.

Such means prefera ly consists in the ro` vision of an inclined l'passage 94 provided in the lifting head 1 which establishes communication between the interior of the hollow plunger 13 and the tapered seat 43 .of the lifting head. A,vent 95 is provided in the lower wall of the hub 40 and this vent is in registration with a semi-annular roove 96 provided in one side of the tapere plug 42 as particularlyv shown in Figure 5. The passage 94, vent- 95 and the groove 96 are so arrangedas to be in alinement with one another, thereby providing a communicating passage leading from the interior ofv the plunger 13 to the exterior thereof. When the oil level in the hollow` plunger 13 is lowered vbythe'pumping of theoil therefrom intothe lower portion of the cylinder beneath the plunger, air will be drawn into the plunger through the vent 95, therebyv preventing the, formation of a Vacuum with- 1n the upper end of the plungel, which would tend to rendery the jack inoperative. Conversely, when the oil is returned from the cylinder, beneath the plun er, back- 'to the interior of the plunger ro 13, the air drawn into the plunger above the oil level will be expelled therefrom'through thepassage 94, groove 96, and vent '95 to the at` vmosphere.

In the operation. of this novel jack, the

plunger and cylinder thereof will first be A filled with a suitable liquid such as oil and the pump rod 63 reciprocated within the.

handle pipe section 64-until the oilvis drawn into the tube as shown in Figure 1, after which the jack is ready for service. lWhen and 5, in which position the port 6 v from the tapered bore 43 in the lifting head desiring to lift a load.. the handle sections are extended or unfolded to substantially a horizontal position as shownlin Figures 4 leading to the upright port 37 will be closedl as par.- ti'cularlyshown in Figure 4. thereby preventing the oil pumpedinto the lower portion of the cylinder from returning through the

ports

56 and 59 to the interior 'of the plunger. As the pump rod 63 iswithdrawn from the tube or pipe 64,- oil will be drawn from the interior of the plunger through the port 33, intake t-ube 18,'port34, around the valve 35,l into the duct 36. through thetavalve 38 after which it will be downwardlyy forced through the upright port 37 and intol the' discharge ipe 19 into the lower portion of the cy inder beneaththe plunger,

` from whence 5 5.

with the resultant raising of such plunger. Continued reciprocation of the pump rod 63` will cause the oil to be pumped from the interior'of the plunger tothe lower portion of the cylinder beneath the plunger until the load has been lifted to the desired height.

When itl is desired to lower' the jack, it is only necessary to slightly lower the intermediate handle section 48 from a'horizontal position until the recess 62 in the plugl 42 is brought into registration with the two

ports

56 and 59, thereby establishing communication between the lower portion of the cylinder and the interior of the plunger.) Owing to the high pressure of the oil beneath the plunger, caused by the load resting thereon, the oil will be A'upwardly forced through the discharge pipe 19, and intoi the upright port 37, through the connecting duct 57, port 56, recess 62, port 59, connecting duet 58 and' into'the upright port 34, it will flow downwardly through the intake pipe 18, through the port 33 and intothe; interior of the plunger, thereby allowing theplunger, -and therefore Y the lifting head to descendtonormal or inoperative position. i

Referring toV Figure 4','it'will be noted that the connecting ducts 57 and 58 are so arranged in the lifting head that the oil owing from the cylinder back to the interior of the plunger will not pass through either

ofthe valves

38 and 35. It will also be noted that the connecting duc-t 58 communicates withthe upright port 34 ata point below Another.

nection between the intermediate handle seetlon 48 and the lifting head of the jack which connect-ion serves av dual purpose. In addition 'to providing a pivotal connection bet-ween the handle and the jack, it also functions as a' safety valve, 'should the effective pressure `in the jack become excessive, as in the case the plunger has reached the top of its stroke wlth the shoulder 29 abutting the stop ring 28 andthe operator continues to manipulate the pump rod 63. Referring toeFigure 3 it will be noted that a clearance is -provided between the face-53 ofthe yboss 4() and the adjacent marginal.

edge ofthe cap 54, when the tapered plug 42.*is vin normal seated position asherev shown. "Thus, should, an excessiveI pressure be built 'up in the plug 42, and therefore ,in the jack'and handle seotlions, such pressure will cause the tapered plug 42 to'be unseated or tobe axially -moved in its tapered seator -bore 43 against the tension of the spring 49. Such axial' movement of the plug 42 'will allowa portion of the oil to-escape through the gap thus provided between the peripheral surface of the plug and the wall of the tapered bore 43, thereby protecting the jack against damage which might occur from excessive oil pressure.

From the foregoing, therefore, itv will be seen -that this novel jack is substantially fool-proof. Its construction is such that it may `be l readilyand conveniently operated also such that itV will be positive and effi; cientin operation and erformance.` Having thus descri d our invention what we claim asnew and'desire to secure by Letters Patent, is: 1. A lifting jack 'comprising in combination, a cylinder, a hollow plunger therein, alifting head on the upper end of the the valve, thereby allowing the y -oil to enter the intake pipe 1 8 beneath the valve 35, with the resultthat the valves re- 'main seated during the vlowering operation of the jack.

feature of this invention resides in-the'novel construction of the pivotal convfrom any posltion of the operator, and is plunger and the lowerplunge-end effecting 'l fluid-tight fit with the inner wall of the cylinder, an inelastic Huid within the plunger. pump means for forcingthe fluid from the interior of the plunger into a substantially 4the lower portion of the cylinder beneath nular space between plunger and cylinder walls O'roovesf'n the enlarged wall ortion of theb plunger communicating wit said annular space, and apertures connecting said the cylinder to the `grooves with the interior of the plun er', 'whereby fluid escaping into .-the lannu ar space from beneath the plunger will be returned to the interior of the plunger.

2. A lifting jack comprising in combinaf vvtion,`a cylinder. a hollow plunger therein,

a lifting head ou the upper endiof the plunger and the lower plunger-end effecting asubstantially fluid-tight fit with the inner wall of the cylinder, an inelastic fluid within the plunger, pump means for forcing the fluid from the interior of the plunger into ythe lower portion of the cylinder beneath.

' the plunger to 'raise it, means for lay-passing the. fluidfrom the cylinder to the interior of the plunger to lower the latter` a portion of the plunger wall being reduced eX-' teriorly thereof to provide an annular space between plunger and cylinder walls, grooves ing into the annular space from-beneath the plunger will be returned to the interior of the plunger, an annular` shoulder on the plunger wall exteriorly thereof 'and adjacent to its lower end, an abutmentring demount'a-bly seated upon the upper end of the cylinder and'overhanging the bore thereof,

tion, a cylinder, a hollow plunger operable therein, a lifting head on the upper end of the. plunger and tlie'lower lplunger-end effecting a substantially fluid-tight fitwith the inner wall of thecylinder, an inelastic fluid within the plunger,y means to pump the fluid from the plunger and force it into the lower portion`of the cylinder beneath the plunger to raise it, means for returning t-he fluid from the cylinder to the interior of the plunger to lowerthe latter` stop means on the exterior of the plunger to limit its raising, the exterior of the plunger Wall having y, a duct therein communica-ting with an aper-l ture tlirou h said wall whereby any fluid escaping a ove the lower plunger-end returns to. the plunger interior`l said aperture being located below saidI stop means.

' In witness whereof, we have hereunto Set our hands this 23rd Iday of May 1924.

- TIMOTHY C. POB/LEROY.l

CARL E. JOHNSON.