US2895622A - Hydraulic jack - Google Patents

Description

A. E. suNDlN HYDRAULIC JACK July 21, 1959 4 Sheets-Sheet 1 Filed Dec. 8. 1955 Il 5V 3 1|//////,7//////// il Z 59 I f July 21, 1959 A. E. sUNDlN HYDRAULIC JACK Filed Dec. 8. 1955 4 Sheets-Sheet 2 25 I 4Z ,9 zo 50 4a v 45 /8 l 4/ 2l f 17 37 4a Il 4 30 Z7 Il qu 9 5a 6 65 59 3L a 70 ,Hl Il;

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7s j c 73 A. E. SUNDIN HYDRAULIC JACK July 21, 1959 4 Sheets-Sheet 3 Filed Deo. 8, 1955 A. E. SUNDIN HYDRAULIC JACK Julyv 21, 1959 4 Sheets-Sheet 4 Filed Dec. 8, 1955 United States Patent relates t'o'a liy'lc'lra'ulic,v lack' especially adapted tofbe `arra1ged" behind the' dr iig compartment of a lorry; by means of'sid'hyd'raul 'ack considerable loads can be lifted from the` ground some distance beneath the lorrybtoth'e platform o'f the latter, and arranged on Ysaid platform as desired', eitherY at"the front or rear of the latter. A I y The invention relates more" particularly to such hy-V draulic jacks which are providedV withv a swingable levier beam that can be swung-"aswell in'a vertical as a zontal direction relative to the body of thehyd'raulic jack, The movement invertical directionjo'f beam is caused 'at least partlyl by a hydraulic device con-A sistingof apressure cyli der withapressurepiston bringsthe lever beam close to the supporting` erd adja- Cenche bodyi Characteristicfor`v the invention isthatj the leverbeaui isprovided with aj swngingairrgactuated; by `aI second pressure cylinder with a pressure piston so that the lever beamcanswing a The present invention loading tool onthe swinging arm not only in avertical-and horizontal direction but also can move vthis tool in a directiontol or frorn'the body, besides whichwthe lever beam with its swinging arm-can becollapsed during'drivingthelorry. v

By'suclr a hydraulic jack a load mayv be placed at a considerable height` as wellat the front as at thevrear part -of -the' body platform if; for instance,bu lk goods Aare inquestion; atthe' same time unloading can bepeformed quickly and Comfortablyby the iaick- An embodimentlof the` invention will be hereinafter describedwith referenceto the accompanying drawings,

inwhich:

Figure 1 shows afvertical 4longitudinal section= through a hydraulicu jack with itsl levery beamturned sidewise kk so that-itwillfbe ina'positionvparallel to andbehind the driving compartmentof the lorry;-this section beingtaken through the'vertical longitudinal middle plane of the 1G u ,.vr .n rlliilgure 2-fshows on-a` somewhat reduced-scale a vertical section through the: upper part-of thefhydraulicjackfpn the` line-lI-'II in Figure l,y ar1`d1a-vertical ,cross section throughk the"l chassis of thevehicley wit-hfY controlV vdevices Jfor the hydralic medium; said devices being-shown diagrammatically; t

Figurer 3v is: a side View, partlyy brokeny olf; of the hy draulieja'ck showin'gthelever bearnfan'd' the swinging aim ofthe jack indifferent positions-.1

Figure l4 is a? side Viewv of'theI swir'rgirrgl arm:

Figure shows a vert'icalfcrosss tio through-the lever bearno theflinef V -VI irri-Ei Referring moie'particularlyit tlei`drvv`ing's'; formed'irail 3 is transversely arranged' on the: frine 1'" o'f the chassis'f of a" lorry closelybehind the driving' com# partaient 2" df the' latter; said' raily 3 frrrisa'coirtainer ice 2 faeprssnr taedium, preferably' oit; which median drives the hydraulicjack.

A'V vertical cylinder 4 is with itslower end arranged at the rail an around the upper end o ffsaidv cylinder 4' is'turnablyjcrried a pressure cylinder 7 by4 means of two bearings 5 and 6; saidcylinder 7 serves as a bodyy for the jack. AA4 gear: Wheel cylinder,jthe teethof said gear wheel 8 engage-arachgear 9, s'aid rack-gear connects two pistons (not shown); each one'of said pistons is movable Iaxially in pressure cylindersll) 4and 11. V y

VThe rack# ear 9 `1s movable axiallyv in a guide 12 in a piece 13; )fi/hielt connects the cylinders 10, 11`v mutually. The tubular body lis provided with a bettom'14'xed above'the cylinder 4,v this` bottom forms a support for the lower end of` a' pressure-piston 15, which is axially movable in the cylinder 7 when the pressure piston is` inyits lower position. Thempiston 15 is movably guided in `two bearings 1d and 17 arranged at some distance from eachother; the upper end of the cylinder 7 is providedv with a bracket arm `18. A horizontal shaft 19'is turnablygcarriedjlatthe free end of the bracket arm 18', which- 's haft `with its ends', supports one end of the channelforrnedj lever beam of the jack.` One part 2 0of-this lever beam is by means of a U-shaped double-link 2.2iAv pivotally connected tothe pressure piston 1 5; TheAv U- shaped double-'link 2 1 consists of two arms 22mutually connegeteld` bya shaft-2j3j-which is pivotallycarried-fin a head Zftfc the upper 'end of the'piston l15; atrtheir free endsofrhthearms 22 are pivotlly connected tqrthe side partsIZ ofthevlevenbeam'by means of pins 26 situated below tbe shaft v15?-` ,t Y A t theendj of the leverbeam and opposed -to the shaft-g1?, acliaimellformedor tubular arm'28is pivotally carriedon, a horigontal shaft 27;the part 29 ofthejarm 2 8 situatedfclosely to the shaft 27 is` channel-formed. A swinging-arm 3Q is' vith one end swingably carried on the shaft"` 27. The free end of the arm 30 is swingably connectedvvitlrnthev outer end of piston by means of-a pin 31. The piston 32 is axially movable in apresinsidethe prt o fthe lever beam. The part 35` (Figures-Zande) at the free'end of the swinging arm 30 is formed somthat it has a good bearing surface againstvthe bottom-- 36 of-the channel (Figure 4) when the lever beamllis turned into a channel-formed part 29 ofl the outer arm 28-ofithelever beam." Y

The vswinging arm 43G is normally kept inthe swungrin p grsitionmshown'in'; Figure ljbymeans of a helicalspring 38 having one of its ends lixed to an attachment 37 at `the inside ofwthe channel-formed inner arm 20 ofy the lever bearn, said springj 38; has its other end connected to a wire 32,1 The latter has its end adjacentto the end connected to the'springS and irst passedover a runner 40 i 1 1 t lre interior of the innerarm'20 of the lever beam and thenconnectednto the swinging arrn 30.

A -tubular bar 41 isaxially movable in the outer arm 28 of the lever beanr,Y said bar' can be secured in different adjustedvpositions (not shoWn'in-thedrawingwn A-chain 42Y is attach'ed at the outer endeof the bar' 41, whiclrchain isfpassedo"ver`a rollerl 44' turnablyicarried 'o'n -av transversal shaft 43-a1ideat the outerT e'ndl providedl withl a lifting hook-'45u` Theirolleri44"isrpiovidediwith a circumferential guiding notched-for obtaining: thee-lower parts lof thisf vertically situated linlsltZof the' chain. Atthe" outer edorfgtlie 41`is`rrii^g d"clain 'shaped linky 48Ttu'r'ably`lc`ar'ii sha e 47, this link iS-serves" asa''blokirg arrangedat the lower end of thi's" linger 49 which has a notch 49a embracing the upper part of the vertically situated links 42a of the chain, and which engages between two'annexed links 42b of the chain on the roller 44, when the blocking device is in its downturned position (see position in Figure The blocking device 48 is kept in this position by a clampedshaped blocking pin 50 provided with a pull handle 51 and is movable in the blocking link 48 by means of two branches 52 and 53. By the actionof a helical spring 54 situated between the blocking device and a washer 55 -at the free end of the upper branch 52 of the clamp, the blocking pin 50 is kept in such position that the lower branch 53 of the clamp engages the outer end of' the bar 41 so that the blocking link 48 cannot be swung upward when the chain 42 is loaded.

The blocking pin 50 can, however, be moved to the right when the handle 51 is pulled to the right, according to FignirerS, against the action of the spring 54 so that the member 53 is pulled ont from the bar 41 whereupon the blocking link 48 can be swung upward, for instance to the position shown with dotted and dash lines in Figure 5; in this position the chain 42 can be drawn over the roller 44 either to the right so that the free end of the chain will be lengthened (Figure 4) or to the left so that the chain will be passed double to the left of the roller (Figure 3); all this depending on the shape and the weight of the load to be lifted by the jack. If the part of the chain on the left hand side of the roller 44 is not used at the lifting, it can be retracted into the tubular bar 41.

`The devices for the control of the feeding of the pressure-medium are only shown diagrammatically in Figure 2. The hydraulic pump 56 (which is here supposed to consist of a pump) is preferably connected ,-With the power take off (not shown) on the gear box of the lorry; The pump 56 is connected through a pipe 57 with the rail 3 serving as a container for the oil. The pressure side of the pump 56 is connected by a pipe 58 with a control valve 59 the valve body of which can be adjusted to different control positions by means of an'operating handle 60, 61 from both sides of the lorry. 'I'he valve 59 is conencted by means of a pipe 62 with the outer end of the pressure cylinder 10, and the valve 59, is connected by means of a pipe 63 with the pressure cylinder 11. The valve 59 is further connected with the interior of the cylinder 7 by means of a tiexible pipe 64. The valve 59 is connected with the interior of the container 3 by means of a return pipe 65. A pipe 66 is branched from the pipe 58 and leading to a second control valve 67 which is connected with the pressure cylinder 34 at its end situated closely to the pin 33 by means of a flexible pipe 68. The control valve 67 is connected with the return pipe 65 by means of a pipe 69 and can also be operated by means of handles 70, 71 from bothr sides of the lorry.

The control valves 59 and 67 may be combined in one single valve but because of the fact that the pipe system shown has been provided with two valves it is easier to explain the action of the jack. If the outer arm 28 of the lever beam is n the position shown in Figure 3, and if by changing of the adjustment of the control valve 67 a certain quantity of the pressure-medium is pressed through the pipe 68 into the cylinder 34, the piston 32 will return the swinging arm 30 in a counter clockwise direction according to Figure 3, whereby the swinging arm 30 with its part 35 pressing against the bottom 36, swings the outer arm 28 of the lever beam in a counter clockwise direction, for instance to the lower position shown with dotted and dash lines in Figure 3. If the bar 41 further is elongated, for instance to the position shown in Figure 4, it is evident that the load will be situated at a considerable distance from the vertical, turning axis when the load is arranged on the hook 45, i.e., the axis around which the cylinder 7 is turning When the control valve 67 then is adjusted to a position in which no more pressure-medium is pressed into the cylinder 34 and the pressure-medium cannot return from this cylinder, the outer arm 28 of the lever beam will evidently remain in the position at the side of the lorry. If the load has to be lifted still higher, the control valve 59 is adjusted with the handles 60, 61 so that the pressure-medium will be pressed through the pipe 64 into the cylinder 7. The pressure piston will then be moved upward whereby dueto -the double link 21, the inner part of the lever beam is turned in a counter clock-Wise direction according to Figures 2 and 3, for instance to the upper position shown with dotted and dash lines. In this position is also indicated that the outer arm 28 of the lever beam by means of the piston 32 can be swung so far upward that it will be situated approximately in the elongation of the inner arm 20 of the lever beam. If the lever beam 20, 28 then is swung in a horizontal plane around the pressure cylinder 7, and the control valve 59 for instance is adjusted so that the pressure-medium is forced through the pipe 62 into the cylinder 10, the piston in the cylinder is pressed to the right according to Figure 2 bringing with it the rack-gear 9 and the piston in the cylinder 11 is pressed through the pipe 63 via the control valve 59 and the return pipe 65 to the container 3. Due to the cooperation between the gear wheel 8 and the rack-gear 9 the cylinder 7 is turned by the movement of the rackgear 9, and by turning of the cylinder 7 the lever beam 20, 28 is swung so that it will pass rearwards over the platform (not shown in the drawings) from the position shown in Figure 2. When the load then has to be lowered on the rear end of the platform, the control valve 59 is adjusted so that the piston 15 moving in the cylinder, due to its weight, the weight of the lever beam 20, 28 and the weight of the load, will force the pressure-medium out of the cylinder through the pipe 64, the control valve 59 and the return pipe 65, to the container 3. 'I'his lowering can however be interrupted any time by closing the valve 59. If on the other hand the load is to be lowered from the upper position shown by dotted and dash lines in Figure 3 so that it will be situated at the front end of the platform close by to the driving compartment 2, the control valve 67 is adjusted by the handles 70, 71 so that the pressure-medium can pass from the cylinder 34 through the pipe 68 via the valve 67 and through the return pipes 69 and 65 -to the container 3. Due to the weight of the outer arm 28 of the lever beam the swinging arm 30 is swung clock-wise according to Figure 3 and thereby forces the piston 32 into the cylinder 34 while the piston forces the pressure-medium out of this cylinder through the pipe 68. When traveling, and when the hydraulic jack is not used the outer arm 28 of the lever beam is swung up on the inner arm 20 of the lever beam (Figure 2) where it takes a relatively small space. By the action of the spring 38 and by pulling in the wire 39, the swinging arm 30 is further swung clock-wise into the outer end of the inner arm 20 of the lever beam. In this position (Figure 2) the outer end of the lever beam does not extend outside the body of the platform. The opposite end of the inner arm 20 of the lever beam is projecting only slightly above the roof of the driving compartment 2.

When the lever beam 20, 28 is swung completely to the side outside the platform of the lorry and when a considerable load is arranged at the outer end of the fully elongated bar 41, the chassis of the lorry is exposed to considerable stresses. In order to reduce these stresses on the chassis the hydraulic jack according to the pres ent invention has been provided with supports. Each of these supports 72 is provided with a supporting plate 73 and are each vertically movable in a cylinder 74 arranged at the outer end of the rail 3. When needed the supports 72 can be lowered to the ground (Figure 2) and the supports 72 may in this position be secured by a handle 75 or the like. It will appear from Figure 2 that the frame of the vehicle is almost completely unloaded by the supports. When the loading operation is iinished, the supports are lifted up again to the position shown with unbroken lines in Figure 2.

The illustrated and described embodiment of the invention is to be considered only as an example and the diierent details of the hydraulic jack may be constructively altered in many ways within the scope of the invention. The pressure cylinder 34 and the piston 32 have been shown as single-acting but they may instead be double-acting, and the piston 32 can be pivotally connected directly at the outer arrn 28 or" the lever beam. ln such a case the outer end of the outer arm 28 of the lever beam may preferably be connected with a dredger ladle, swinging in a vertical plane, so that the hydraulic jack also can be used as a digging machine. With the hydraulic jack, according to the invention, timber and other heavy objects can be dragged towards the lorry. Different embodiments of the control valves 59 and 67 or of a combined valve are possible within the scope of the invention. The double-link 21 which is adapted to unload the lifting piston in such a way that it will not be exposed to any detrimental stresses from the side can, if desired, be shaped and arranged so that it, when loaded, is exposed to pressure-stresses instead of tension-stresses. Even the device for the swinging of the cylinder 7 can be varied in many ways within the scope of the invention.

What I claim is:

1. An hydraulic jack especially adapted to be arranged on a lorry, a lever beam swingable in a vertical and horizontal direction relative to the body of said jack, said lever beam comprising an outer and an inner lever arm, a bracket arm swingable in a vertical plane and hinged at the joint between said outer and inner lever arm, a cylinder having a pressure piston pivotally connected to said bracket arm at its end and arranged opposite the end hinged at said joint, said bracket arm being arranged to abut against said outer lever arm near its joint with said inner lever arm when said lever beam is in a loading position, whereby said outer lever arm is capable off being swung up onto said inner lever arm.

2. An hydraulic jack as set forth in claim 1, characterized by the fact that said cylinder on the inner lever arm of said lever beam at the end opposite said pressure piston is swingably carried in said inner lever arm of said lever beam.

3. An hydraulic jack especially adapted to be arranged on a lorry, a lever beam swingable in a vertical and horizontal direction relative to the body of said jack, said lever beam comprising an outer and an inner lever arm, a bracket arm swingable in a vertical plane and hinged at the joint between said outer and inner lever arm, a cylinder having a pressure piston pivotally connected to said bracket arm at its end and situated opposite the end hinged at said joint, said bracket arm being arranged to abut against said outer lever arm near its joint lwith said inner lever arm when said lever beam is in a loading position, whereby said outer lever arm is capable of being swung up onto saidinner lever arm, a spring member adapted to keep said bracket arm swung into said inner lever arm, said spring member tending to draw the free end of said bracket arm connected to said pressure piston, towards the cylinder of the latter, said cylinder being arranged on the inner lever arm of said lever beam, the cylinder being pivotally connected to said bracket arm when the latter is not exposed to hydraulic pressure.

References Cited in the file of this patent UNITED STATES PATENTS 2,406,620 Luckett Aug. 27, 1946 2,598,517 Drott May 27, 1952 2,621,803 Taylor Dec. 16, 1952 2,639,826 Wolden May 26, 1953 2,676,837 Wagner et al. Apr. 27, 1954 2,682,957 Holmes July 6, 1954 2,689,656 Przybylski Sept. 21, 1954 2,712,878 Sutton et al. July 12, 1955

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