US2213285A - Lifting jack - Google Patents

Description

Septn 3, 1940.77`

H. NlLsoN -LIFTING JACK Filed Feb. 1o, 1940 3 Sheets-Sheet 2 NVENTOR s sheets-shunt 3 om M Sept. 3,r 1940. Hf ANlLsoN LIFTING JACK Filed Feb. 1Q', 1940 f Patented Sept. 3,

UNITED STATES LIFTING JAC'K Harold Nilson, Wayzata, Minn., assigner to George H. Ische, Milwaukee, Wis. 1

o Application February 10, 1940, Serial No. 318,282

12 Claims.

This invention relates to new and useful improvements in lifting jacks, and more particularly to such jacks of the hydraulic type, comprising a lifting member adapted to be moved into or' out of engagement with a load.

Hydraulic lifting jacks, such as are commonly used in connection with automobiles and trucks, usually comprise an operating handle ormember for actuating the pump means to move the load.

In such jacks it is usually necessary that the operating member or handle be operated a considerable time to move the lifting arm from its l5 normal inoperative position into engagement with the load. This often requires considerable time and is objectionable. It is therefore desirable to provide a jack having an operating mechanism which is so constructed that the lifting member of the jack may be swung quickly into engagement with the load, with a minimummovement of the operating handle thereby expediting the operation of elevating the load to the desired height. y

The novel lifting lack herein disclosed, has been designed in such a manner that the time required to move thelifting member from its normal inoperative position, into engagement with the load, may be accomplished by a lsingle movement of the operating handle, thereby greatly facilitating the operation of moving the lifting member into engagement with the load, after which the operating handle may be operated in the usual manner to actuate the pump means and .3 therebyV force the fluid into one end of the cylinder against the piston head of the plunger, thereby to operate the liftingarm to elevate the load.

An object of the invention, therefore, is to provide a hydraulic jack, having a fluid circulating ,mf pump provided with an operating handle by means associated therewith, whereby the lifting ,member or head of the jack may be moved directly into engagement with the load by a singl movement of the operating handle.

a lifting jack comprising a suitable supporting frame having a lifting arm. pivotally mounted thereon, and a cylinder being pivotally connected to the lifting ann and having a plunger operable therein, one end of which is pivotally connected to the supporting frame, and pump means having an operating handle mounted for pivotal movement to operate the pump means, and said handle having means selectively operable thereon for u temporarily locking the handle against pumping lifting arm into or out of engagement with the- A further object of the invention is to provide movement, and whereby the lifting member may be moved directly into engagement with the load, upon initial movement of the handle.

A further object resides in the provision of a hydraulic jack comprising a cylinder and plunger, 5 and pump means for circulating the fluid within the cylinder to operate the jack, and said pump having an operating handle so arranged with reispect to the pump means and cylinder that the force exerted on the handle to force the fluid into the cylinder to operate the lifting member is additive to the force of the uid injected into the .cylinder to operate the plunger.

Other objects of the invention reside in the simple and inexpensive construction of the jack, 16 whereby it may be manufactured at small cost; in the arrangement of the handle and the means connected therewith for causing the lifting member to swing directly into engagement with the load, upon initial movement of the handle; in the 20 means carried on the handle for operating the relief valve to release the fluid from the cylinder and permit the lifting member to return to its normal inoperative position, and whereby the release valve may be operated, regardless ofthe position of the handle with respect to the cylinder; in the unique arrangement of the cylinder and plunger, and the manner of pivotally supporting the operating handle on the cylinder, whereby the cylinder and operating handle may be constructed as a unit, independently of the lifting arm and supporting frame, thereby to facilitate manufacture; and in the novel arrangement of the check valves of the pump, whereby the fluid may circulate freely from one end of the cylinder to the other, when the handle is l initially operated to move the lifting member directly into engagement with the load, and whereby the uid will act as a check to prevent return movement of the lifting member, when the operating handle is released therefrom.

Other objects ofthe invention will appear from the following description and accompanying drawings and will be pointed out in the annexed claims. 45

In the accompanying drawings there has been 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 follow.

In the drawings:

Figure `1 is a vertical sectional view on theline 55 i I-I of Figure 4, showing the lifting member in its normal inoperative position; 1

Figure 2 is an'enlarged detail sectional view showing the operating handle in a lowered position;

Figure 3 is a longitudinal section on the line 3-3 of Figure 4, showing the lifting member moved into engagement with a load;

Figure 4 is a topview of Figure l; v

Figure 5 is a cross-sectional view on the line 5-5 of Figure 2, showing the pump check valves;

Figure 6 is a detail sectional view on the line 8--8 of Figure 5; and

Figure rI is a view showing the means associated with the handle, whereby the lifting member may r' be moved directly into engagement with the load,

upon initial movement of the operating handle.

'I'he novel Jack herein disclosed is shown comprising a suitable supporting frame, generally indicated by the numeral 2, and comprising side members 3 and 4 and axles 5 and 8 upon the outer ends of which suitable carrying wheels 1 and 8 are mounted, as shown in Figure 4.' If

desired, the side members 3 and 4 may be flxedly on a cross rod shown having reduced end porv tions I2 received in suitable apertures provided in the side frame members 3 and 4. 'Ihe end portions |2 of the rod are threaded to receive suitable securing nuts |3, as best shown in Figure 4.

The lifting arm 9 has pivotally mounted upon its outer or swinging end, a lifting head I4 adapted to engage a load i5, indicated in dotted lines in Figure 3. Links I6 each have one end pivotally connected to the lifting head |4 and their opposite ends to the side frame members 3 and 4 by suitable pivots |1, shown fixed to the links i6. The pivots l1 are received in suitable apertures provided in the side members 3 and 4 of the supporting frame. Y

The means provided foroperating the lifting arm 9 is best shown in Figures 1, 2, and 4, and comprises a cylinder |3 provided at one end with spaced arms I9, which are apertured to receive a pivot pin 2| upon which a suitable operating handle, generally designed by the numeral 22, is pivotally mounted. A piston rod 23 has one end supported in a suitable cross head 24 having reduced terminals 25 pivotally mounted in the side frame members 3 and 4, as best shown in Figure 4. A piston head, generally indicated by the numeral 28, is secured to the opposite end of the piston rod 23 and is mounted for reciprocal movement within the bore of the cylinder I8, as clearly shown in Figures 1 and 2. The cylinder is provided at one end with a suitable head 21, bored to receive the piston rod 23, as shown in Figure 2. The cylinder head 21 is provided` with suitable packing glands for preventing leakage around the piston rod 23, as is customary in devices of this general character. The cylinder head 21 is also preferably provided on its inner side with a suitable `sealing element 30, to prevent the pressure fluid in the cylinder from escaping thru `the joint between the cylinder head 21 and cylinder wall. The piston head, it will be noted by reference to Figure 2, comprises a' metallic member 28 which leather cup or packing 29 secured thereto by suitable screws 3|.

In the structure, as illustrated in Figures 1 and 2, the cylinder |8 is movable with respect to the piston head 26, the latter being fixed against longitudinal movement as a result of its connection with the cross head 24. The cylinder i3 is pivotally connected to the lifting arm 9 by a suitable tranverse pivot pin 32, whereby when the cylinder is longitudinally moved in a direction towards the left, when viewed as shown in Figures 1 and 2, the lifting arm 9 will swing upwardly,

as shown in Figure 3.

To thus operate the cylinder with respect to the piston head 26, means is provided for pumping an inelastic iiuid into the space or chamber 33 provided between the cylinder head 21 and the piston 28. Such iluld circulating means is shown comprising a conduit 34 having one end in communication with the chamber 33, as shown in Fig- . ures 1 and 2. The opposite end of the conduit 34 is connected to a depending portion 35 of the cylinder I8. A valve chamber 3E isprovided within the depending portion 35, as shown in Figure 6. A check valve 31 is provided within the valve chamber 3B and Icontrolsfiluid circulation from the valve chamber`38 thrua passage 38shown in Figure 6. The passage 38 establishes communication between the valve chamberv 38 and a second valve chamber 39, having 'a check'valve 4| therein for controlling fluid circulation from a chamber 42 through a suitable port 43, shown in Figure 5. The check valves 31 and 4| control the flow of uid from the chamber 42 to the opposite end of the cylinder or chamber 33, when the pump means is operated.

Apump cylinder generally indicated by the numeral 44 is shown provided with a reduced threaded end portion 45 received in a threaded socket A48 provided in the depending portion 35 of the cylinder. A passage 41 establishes communication between the passage 38 and the bore 48 of the pump cylinder 44, as best shown in Figure 6. A piston 49 is mounted for reciprocal movementin the pump cylinder 44, and is provided at one end with a suitable packing 5|, shown in Figure 2. A suitable packing gland 52 is provided inthe outer end of the pump cylinder 44 to prevent leakage around the pump piston 49.

The means for operating the pump piston 48 is best shown in Figures 1 and 2, and comprises an actuating member, generally indicated by the numeral 53. 'This member is mountedfor rocking movement on the cross pin 2| of the handle 22. The actuating member 53 is connected to the pump piston 49 by a suitable pin 54, which pin is received in a notch provided in the pump piston, whereby when the actuating member 53 is oscillated about the axis of the pivot pin 2|, reciprocal movement is imparted to the pump piston 49. A suitable spring 55 has one end connected tothe actuating member 53 and its opposite end to the pump cylinder 44 and constantly urges the actuating member in a.direction to move the pump piston 49 outwardly to the position shown in Figure 1. The actuating member 53 is operated by oscillation of the operating handle 22.

To thus operate the actuating member 53, the latter is provided with a projection 58 .adapted to be engaged by a yoke 51 having its spaced arms 58 mounted on the pivot pin 2|. The yoke 51 is shown provided with a cylindrical portion 59 having a bore 6| therein for receiving the tubular operating handle 22. The bottom of the bore 6| is threaded as shown at 62 to receive the lower threaded end portion of the tubularoperating handle 22. When the operating handle is oscillated from the position shown in Figure 1 to that shown in Figure 2, the yoke 51 engages the projection 56 of the pump actuating member 53,l

whereby the member 53 is rocked upon the pivot pin 2| and thereby operates the pump piston 49 as will readily be understood by reference to Figures 1 and 2; Such operation of the pump 44 will cause fluid to be drawn from the chamber 42 in the cylinder into the conduit 34, from whence it is pumped into the chamber 33, and thereby imparts reciprocal movement to the cylinder with respect to the piston head 26. Such reciprocal movement of the cylinder will, as hereinbefore stated, impart swinging movement to the lifting arm 9, be'- cause of the arm 9 being connected to the cylinder by the pin 32.

The operating handle, as best illustrated in Figure '1, is preferably made of two sections 63 and 64, arranged in telescopingrelation and secured together by a suitable lock screw 65, which for convenience, may be threaded into the wall of the section 64, as shown in Figure 1. A slot 66 is provided in the adjacent end of the handle section 63, adapted to receive the lock screw 65. -Means is provided for releasing the fluid from the chamber 33, in the cylinder when it is desired to lower the lifting arm out of lengagement with the 1oad.l5. Such means is best illustrated in Figure 2, and comprises a conduit 61 having one end in communication with` the chamber 33 and its opposite end communicating with a valve chamber 68, shown provided in ay sleeve 69, mounted in a bore 10 provided in a portion of the cylinder I8. The sleeve 69 has a threaded portion 1| received in threaded en-` gagement with thegwall ofthe bore 18, as shown in Figure 2. The sleeve 69 has formed thereon a cup-shaped portion 12 which is internally threaded to receive a packing gland 13 and a suitable packing 14.

A spring-actuating check valve 15 is flisposed within the valve chamber 68 andA normally closes a passage 16 establishing communication between the valve chamber and a port 11 leading to the chamber 42 of the cylinder I8.

Means is provided `for unseating the check valve 15 to 'permit the fluid in the cylinder chamber 33 to return to the storage chamber 42 when it isv desired to lower the jack. Such means is 'shown comprising an actuating pin 18 which is mounted in the bore of the packing gland 13 and has a reduced end portion 19 ex'- tending into the passage 16 in alinement with the check valve 15. Axial movement of the pin 18 in one direction will unseat the check valve 15 and permit the fluid in the chamber 33 to return to the reservoir 42 via the conduit 61.

The means for actuating the pin 18 is shown comprising a cap 8l, received in threaded engagement with the cup-shaped portion 12 of the sleeve 68. One end of a flexible shaft, generally indicated by the numeral 82 is secured to the cap 8l and its opposite end to an elongated head 83 which preferably is square in cross section.y The head 83 is received in a correspondingly shaped sleeve member 84, mountedv for rotary movement in the handle section 63, as shown in Figure 1.

vOne end of an articulated operating stem 85 is secured to the sleeve 84. The other endof the stem. 85 is provided with a finger knob 86, received in threaded engagement with the upper end of the handle section 64, as shown in Figure 1. Rotation of the finger knob 86 will impart rotary movement to the flexible shaft 82 whereby the cap 8| is relatively rotated on the cup-shaped portion 12 of the valve cage sleeve 68, whereby axial movement is imparted to the cap 8| with respect to the head 13. Such relative axial movement of the cap 8| will impart longitudinal movement to the pin 18, whereby the check valve 1,5 may readily and conveniently be unseated to permit the fluid in the chamber 33 to return to the chamber 42, by the simple manipulation of the finger knob 86, conveniently located at the end of the operating handle 22. The ilexible shaft 82 permits free swinging movement of the operating handle 22 without interfering with the 'operation of the release valve 15 and its operating mechanism. y

Another important feature of the apparatus reside's in the arrangement of the cheek valves 31 and 4|the springs of which are such that upon the slightest movement of the cylinder I8 with respect to the piston head 26, in a direction `to elevate the lifting arm 9, a portion of the oil or fluid in the chamber 42 may pass .freely through said check valves and the conduit 34, into thev chamber 33 at the opposite end of the cylinder. The release valve 15 may be retained upon its s eat by a relatively stiff spring, because this valve may be forcibly unseated by manipulation of the linger knob 86 on the operating handle.

Another feature of the inventionA resides in the means provided for moving the lifting head directly into engagement with the load, upon the initial movement of the operating handle. Such means is best shown in Figures 3,4, and 7, and comprises a disk 81, which is loosely mounted on the pivot pin 2| of the operating handle, adjacent to one of the arms 58 of the handle yoke 51. The disk 81 has an arm 88 secured thereto, the outer end of which is pivotally connected to one end of an arm 89, loosely mounted on the pivot I of the lifting arm 9.

A friction shoe 9| is mounted on one end of a b ar 92 which passes through suitable apertures provided in the cylindrical portion 59 of the operating handle, as best shown in Figure 4. The bar 92 is preferably tapered, as shown in Figure 4, and is retained in position by suitable cotter pins 93, received in apertures provided in the ends of the bar 92. The friction shoe 9| iswhereupon the threaded connection 62 providedy between the lower end of the handleV section 63 and the bottom of the socket member 59, will impart axial movement to the handle section -63 in the socket member 59. Such relative axial 'movement of the handle section 63 will cause the lower end thereof to engage the bar 92 and force it downwardly, whereupon the friction shoe 9| may frictionally engage the disk 81 with sufficient resistance to lock the handle 22 to the disk 81, whereby these two parts may be rotated as a unit upon the pivot pin 2|.

When the operating handle is in the position shown in Figures 1 and 7, and the friction shoe 9| has been forced into frictional engagement with the disk 81, downward movement of the operating handle from the position shown in Figure 7 to that shown in Figure 3, will cause the' cylinder |8 to move forwardly as a result of the arm 88'being connected tothe pivot pin II of the lifting arm by the arm 89. When the cylinder is thus moved forwardly, upon initial downward movement of the operating handle, a portion of the oil in the reservoir or storage chamber 42 will ow through the check valves 31 and 4I. conduit 34, and into chamber 33 at the opposite end of the piston head 28, without reatively rotates the handle 22 with respect to the socket member 59, in a direction to release the friction shoe 9|, from the disk 81, after which the operating handle may readily be oscillated to actuate the fluid pump. 44, thereby to forcibly pump additional fluid into the chamber 33 from the chamber 42. Continued oscillation of the operating handle 22 will cause the lifting head I4 to elevate the load I5 to the desired elevation. The friction disk 81 and shoe 9| make it possible to'quickly adjust the handle for swinging the lifting head I4 directly into engagement with the load, which is highly desirable in that the usual time required to move the lifting head into engagement with the load by operating a pump, is reduced to a minimum. After thelifting head has been moved directly into engagement with the load, by initial movement of the operating handle 22, the handle is operated in the usual manner to operate the fluid circulating pump 44 to elevate the load. When itis desired to lower the load, the operator simply rotates the hand knob 8S in a direction to move the cap 8i in a direction towards the release check valve 15, whereupon the valve opening pin 13 will engage the check valve 15 and move it out of engagement with its seat. The iiuid in the chamber 33 is then free to return to the storage chamber throug the open check valve 15.

The novel jack herein disclosed has been found very practicalin actual operation. One of the important features of the invention, as hereinbefore stated, resides in the arrangement whereby the lifting head I4 may be moved directly into engagement'with the load by a single downward movement of the operating handle, without operating the pump 44. In jacks of ordinary construction, it is necessary to operate the pump to gradually elevate the lifting head I4 from its normal inoperative position as shown, for example, in Figure l, until the head reaches a position in engagement with the load, as shown in Figure 3. This may require several strokes of the pump handle and therefore requires considerable time. The frictionvdisk and shoe 81 and 9 I, respectively, makes it possible to move the lifting head I4 from the position shown in Figure 1 directly into engagement with the load by a single stroke of the handle, which, to the best of my knowledge, has never heretofore been accomplished in the construction of a jack of this type.

Another important feature resides in the arrangement of the check valves 31 and 4I, whereby they positively prevent fiuid flow in one direction, but permit free and unrestricted ow in the opposite direction, or in a direction from the reservoir or chamber 42 to the chamber 33. The

cylinder I8, including the chambers 33 and 42, and the conduit 34 is filled with an inelastic fluid, such as oil, to substantially-the level shown in Figure 2, whereby it will be noted that an air space is provided above the level of the oil. 'I'he amount of oil introduced into the cylinder is such that when the piston is in the dotted line position shown at A in Figure 2, an air space is provided over the oil level in chamber 42. 'I'he air in this space may be under a slight pressure because of the displacement of oil in chamber 33 by the piston rod 23. In other words, when the cylinder is moved relatively to the piston head 26 to transfer oil from chamber 42 into chamber 33, the piston rod 33 passing through chamber 33 will reduce the capacity of this chamber with respect to the capacity of the cylinder atV the opposite side of the piston head. The pressure which may thus develop in chamber 42 is additive to the force of the fluid injected into the chamber 33 of the cylinder by manipulation of the pump handle 22, which therefore facilitates the operation of the pump.

'Ihe entire jack is extremely simple and inexpensive in construction and may be manufactured at small cost. Its operation is accomplished entirely by manipulation of the operating handle 22, as hereinbefore described. To facilitate shipment, the upper section 64 of the operating handle may readily be detached by simply unloosening the screw 65, whereupon the section 64, including the stem 85 and sleeve 84, may be Withdrawn from the handle section 83, as will readily be understood.

I claim:

1. In combination with a lifting jack comprising a supporting frame, a lifting member, an actuating mechanism fo'3q the lifting member,and an operating memberrfor the actuating mechanism, of means whereby the initial movement of the operating member may swing the lifting member directly into engagement with the load.

2. In combination with a lifting jack comprising a supporting frame, a lifting member, an a'ctuating mechanism for the lifting member, and

I an operating handle for the actuating mechanism, of means whereby the initial movement of the operating handle may swing the lifting member directly into engagement with the load without operating the actuating mechanism.

3. In combination with a jack comprising a supporting frame, a lifting member, a hydraulic mechanism for actuating the lifting member including a fluid pump, andan operating handle for the pump, of means whereby the initial movement of the operating handle may swing the lifting member directly into engagement with the load without operating the fluid pump.

4. In combination with a lifting jack Acomprising a supporting frame, a lifting member, an actuating mechanism for the lifting member, and anoperating handle for the actuating mechanism, of means carried by the operating handlel and selectively operable to Acause the initial movement of the operating handle to swing the lifting vmember directly into engagement with the load operating handle for the pump, of friction means swung into engagement with the load by manipulation of the operating handle and without operating the pump.

7. In a lifting jack, a suitable support, a lifting member pivoted at one end to the support, a cylinder pivoted to the lifting member and having a plunger operable therein, one end of whichv is pivotally connected to the support, an inelastic fluid in the cylinder, a pump for circulating the. fluid within the cylinder to elevate the lifting member, an operating handle for actuating the pumpmeans, and means independent of the pump for operatively connecting the operating handle to the lifting member whereby the lifting member may be moved into engagement with a load without operating the pump.

8. In a lifting jack, a suitable support, a lifting member pivoted at one end to the support, a cylinder pivoted -to the lifting member and having a plunger operable therein, one endof which is pivotally connected to the support, an inelastic fluid in the cylinder, a pump for pumping fluid into one end of the cylinder to yimpart movement thereto relatively to the plunger, thereby to elevate the lifting member, an operating handle for load by la single -stroke of the operating handle, after which the operating handle is operated to actuate the pump, whereby the lifting member may elevate the load.

9. In a jack, a suitable support, a lifting arm pivoted thereon, a cylinder pivotally lconnected -to the lifting arm and having an inelastic fluid therein, a plunger operable in vsaid cylinder and vhaving one end secured to the support, whereby Athe plunger is locked against longitudinal moven ment, a pump for pumping the uid into one end of the cylinder to elevate the lifting member, an operating handle for the pump mounted for pivotal movement with respectto the cylinder, and

-means whereby a single stroke of the operating handle may move the lifting member directly into engagement:v with-the load, upon initial movement of the handle.

i0. In a jack of the class described, a wheel supported frame, a lifting arm mounted for pivotal movement thereon about a'transverse pivot. a cylinder having one end pivotally connected to the lifting arm; a reservoir, an inelastic uid in said reservoir, a plunger having one end slidably supported 4in the cylinder and its opposite end connected to the supporting frame, a pump for pumping iiluid1 from the reservoir intoithe cylinder, thereby to' impart relative longitudinal movement to the plunger and cylinder-in opposite di.

rections, whereby the lifting arm is elevated, a handle for operating the pump, a 'release valve, means on the pump handle for opening'the release valve to permit the fluid to return to the reservoir, whereby the lifting-arm may' return to its normal inoperative position, said release valve operating means being so arranged that it may be operated at any point in the stroke of the A operating handle. l

1l..In a jack of the class described, a wheel supported frame, a pivot pin mountedtherein, a.

lifting arm mounted for swinging movement on said pivot pin, a cylinder having one end pivotally connected to the lifting arm and having a reservoir therein, an'inelastic fluid in the reservoir, a plunger having one end slidably supported in the cylinder and its opposite'end pivotally cony nected to the supporting frame, a 'pump for pumping fluid from the reservoir into the opposite end of the cylinder, thereby to impart relative longitudinal movement to the cylinder,

thereby to elevate the lifting arm, a handle pivotally mounted on the cylinder and adapted to operate the pump,'a release valve, means carried by the handle for opening said valve to permit the Yuid to return tothe reservoir, whereby the lifting arm may return to its normal inoperative position, and link means connecting said pivot and its opposite end pivotally connected to the supporting frame, an inelastic fluid in the cylinder, a pump carried by the cylinder for pumping.

fluid from one end of the cylinder to thevother, thereby to .impart longitudinal movement to the cylinder with respect to the plunger, whereby the lifting member is elevated, a handle pivotally mounted on the cylinder, means for operatively.

connecting the handle to the pump, whereby os-- cillation of the handle will operate the pump.

a pair of links mounted on the pivots of the lift-.-

ing member and handle, respectively, and having their adjacent ends pivotally connected together, a friction disk secured to the link supported on the handle pivot, and a friction shoe carried by the handle and'having means whereby it may be lmoved into frictional engagement with the fric- L tion disk, vwhereby movement of the handle may l impart relative longitudinal movement to the cylinder and causethe lifting member to move directly into engagement with the load by a sin gie stroke of the handle.v

mmm NrLsoN.

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