US1576836A

US1576836A - Portable jack

Info

Publication number: US1576836A
Application number: US718801A
Authority: US
Inventors: Thomas J Mccarthy
Original assignee: Individual
Current assignee: Individual
Priority date: 1924-06-09
Filing date: 1924-06-09
Publication date: 1926-03-16
Anticipated expiration: 1943-03-16

Description

March 16 1926.

T. J. M CARTHY PORTABLE JACK Filed June 9, 1924 Patented Mar. 1 3:, 1226.

UNITE STTES THOMAS J. MCCARTHY, 0F 110$ ANGELES, CALIFORNIA...

PORTABLE JACK.

Application filed June 9, 1924.

To all whom it may concern:

Be it known that I TnoMAs J. MolAR'rHY, a citizen of the United States, residing at Los Angelcs, in the county of Los Angeles and State of California, have invented new and useful Improvements in Portable Jacks, of which the following is a specification.

This invention consists of the novel fea tures herein shown, described and claimed.

The leading object is to make a jack having a supporting frame mounted on wheels and having a tongue for manipulating the location of the supporting frame, the tongue also being adapted to serve as the jack lever.

Other objects and advantages will appear from the drawings and specification.

The drawings illustrate the details of construction and operation of a portable jack embodying the principles of the invention.

Figure 1 is a top plan view of the portable jack as seen looking downwardly in Fig. 2, as indicated by the arrow 1.

Fig. 2 is a side elevation looking in the direction indicated by the arrow 2 in Fig. 1.

Fig. 3 is a sectional elevation on a plane parallel with Fig. 2 and on the line 8-3 of Fig. 1, and looking in the direction indi cated by the arrows, and showing an operation.

Fig. 4 is a view analogous to Fig. 8 and showing a different operation.

Fig. 5 is an enlarged fragmentary detail of the jack dogs shown in Figs. 3 and 4.

The details of construction and operation shown in the drawings are as follows:

The main frame consists of tour arms 1 arranged radially and flat. Bearing blocks 2 extend upwardly from the arms 1 and the caster wheels 3 have shanks mounted in the bearing blocks 2. A hearing block 4 extends upwardly from the center of the "frame 1 and ribs 5 connect the bearing block 4- to the bearing blocks 2. A housing 6 p is formed integral with the arms 1 half way between two bearing blocks 2. A rectan gular or square opening 7 is formed vertically through the bearing block 4 and the lifting member 8 is slidingly mounted in the opening 7 and has ratchet teeth 9 upon one side. The lifting member 8 is hollow and a flat head 10 has a hollow shank 11 fitting in the upper end of the hollow of the lifting member 8.

A secondarii lifting head 12 has a shank fitting-in t e hollow of the shank 11 and Serial No. 718,801.

a supporting flange 14L resting upon the head 10. The secondary head 12 is adapted to be removed and the shank 13 inserted into the opening 15 in the arms 1 out of the way when its use is not desired. The secondary head 12 serves to make the lifting member 8 higher or lower as desired.

The lever prongs 16 and 17 are formed integral with clamping members 18 and 19 and the hand lever and ton ue member 20 is inserted between the clamping members 18 and 19 and bolts applied to secure the members together. A supporting dog 21 is placed between the

prongs

16 and 17 and a pivot bolt 22 is inserted through the prongs, through the housing and through the holding dog 21 so as to pivotally mount the handle construction and pivotally mount the dog 21 to support the lifting member 8 when the upper end of the dog is in engagement with one of the ratchet teeth 9. So far as the supporting operation is concerned,

it is immaterial whether the lever construc- 1 tion is up or down. A lifting dog 23 is mounted between the pron s 16 and 17 upon a pivot 24, the upper end or the dog 23 being adapted to engage a ratchet tooth 9 and raise the lifting member 8 when the handle.

goes down. Slots are formed through the

dogs

21 and 23 below their upper ends and above the pivots, and a leaf spring 25 is mounted in the slots upon pins inserted through the dogs, the tension of the spring being exerted to press the uppcrends of the dogs away from each other.

Bifurcated

ears

26 and 27 extend down wardly from the

dogs

21 and 23 respectively. A slotted link 28 is mounted the bifurcations oi the

ears

26 and 27 and

pins

29 and 30 extend through the

ears

26 and 27 respectively and through theslots in the link 28. An expansive spring 31 is inserted in the slot of the link 28 against the pin 29. A chain 32 is connected to the link 28 and extends through the hollow of the handle member 20 to the bell crank lever 33. A fitting 8% is clampedupon the swinging outer end of thelever member 20 and has a handle 35 oflj'setlaterally from the axis of the handle member 20 and has a second handle 86 extending laterally. An eye, 37 is attached to a chain 38 and the chain extends through the fitting 34 through the handle member 20 and laterally through the housing 6 and is connected to a pin 39 tired in the lower end of thelitting member 8 ,so that when desired the eye 37 may be pulled to quickly raise the lifting member 8 into engagement with the object to be lifted. The bell crank lever 33 is connected to the handle member by a pin 40.

When it is desired to operate the jack to elevate the lifting member 8, the handle member is grasped in one hand and the bell crank lever grasped with the same hand to pull on the chain thereby pulling on the lower end of the dog 23 to bring the upper end of the dog into engagement with the ratchet teeth 9, then as the handle is moved up and down the lifting member 8 will be raised to the desired extent and the dog 21 will hold the lifting member in its elevated position.

The portable jack is intended especially for use around motor vehicle for raising the axles to remove and replace tires, and so on, and the handle construction, including the member 20, is of considerable length and serves as a tongue so that the lifting and supporting mechanism may be readily run under the vehicle to a desired position. After the supporting mechanism has been properly located a pull on the eye 37 will instantly raise the lifting member 8 into engagement with the axle or other part to be raised and then one or more strokes of the hand lever mechanism up and down will lift the part to the desired extent. If the part is low, as when a tire is fiat, the secondary head may be removed and if the parts are of abnormal height the secondary head is used. After the operations have been per formed and it is desired to remove the jack, the bell crank lever 33 is released and the handles pressed clear down to the floor or ground and then the dog 23 will contact with the dog 21 and press the dog 21 out of engagement with the teeth 9 and the spring will hold the dog 21 out of engagement, and as the handle is elevated the lifting member 8 will go down considerable distance, and if this is not sud lent the operation may be repeated.

The operation of lowering the jack given in detail is substantially as follows:

It is to be noted that the holding dog 21 has no up and down motion, being swivelled on the pivot bolt 22 on which the handle has a levering operation. The lift; ing dog 23 moves up and down. These dogs are pressed apart at their upper ends by the spring 25 and arepressed together at their upper ends by the action of-the spring 31. This action, however, has lost motion on account of the pin 30 moving in a slot and functioning to thrust the lower ends of the dogs apart.

As above mentioned when it is desired to lower the jack the hand lever is pressed clear down to. the floor into a lower position than shown in Fig.4, causing the dog 23 to disengage the dog 21 from the teeth. The dog 21 will thereby be thrust out a considerable distance from the rack 9. The handle is then raised and lowers the jack on the lifting dog 28.

In a certain position of the downward movement the )in 30 moves from the position shown in t 1e slot in Fig. 5 to the other end of the slot and exerts a compressive stress on the spring 31. holding dog 21 into engagement with the racl. The further upward movement of the handle lowers the lifting dog and the spring 31 exerting a stress to separate the lower ends of the dogs and draws the upper ends the dogs together, thereby completely disengaging the lifting dog 23 from the rack, the rack being held in this position by the holding dog 21. The handle is then given an idle stroke downwardly which elerates the lifting dog until the reaction of the spring 25 thrusts it into engagement with one of the teeth. hen the weight is taken oft the holding dog 21 on to the lifting dog 23, the holding dog is forced outwardly as above described and the upward movement of the handle gives a lowering action of the jack. This action may be repeated as many times as is necessary to completely lower the jack.

In the lowering operation it is unneccs sary to manipulate the bell crank lever 33. However, it may be actuated if desired to positively force the lifting dog 23 into engagement with the rack in any position.

Especial attention is called to the use of the

handle parts

20, 35 and 36 as a tongue for manipulating the lifting and supporting mechanism and as a lever for operating the ack.

When desired, the portable jack may be run under the center of either end of a motor vehicle and operated to lift the end of the vehicle, thereby placing the weight upon the casters of the jack, and then by manipulating the tongue the end of the motor vehicle may be moved laterally at right angles to the running line of'the vehicle, and by repeating this operation both ends of the vehicle may be moved laterally to any desired extent.

Various changes may be made without departing from the spirit of the invention as claimed.

I claim:

1. A jack having a supporting frame, lifting member mounted thereon and having a rack, a lever pivoted on the frame, a pivottherefor, a holding dog pivoted on the same pivot as the lever, a lifting dog pivoted between the said pivot and the rack. a tension device operating with the lever and connected to both dogs whereby both dogs engage the 'ack when the lever is operated to elevate the lifting member, and means to re- This forces the lease the tension device and disengage the.

holding dog from the rack to lower the lifting member.

2. A jack as claimed in claim 1 in which the tension device comprises a slotted plate, pins on said dogs engaging said slots, and means attached to the lever to draw and release said plate.

3. A jack as claimed in claim 1 having a spring connecting said dogs to force their teeth away from each other to disengage the holding dog from the hack.

1-. A jack as cla med in claim 1 in which the tension device comprises a slotted plate, pins on said dogs engaging said slots, means attached to the lever to draw and release said plate, and a spring connecting said dogs to force their teeth away from each other to disengage the holding dog from the rack.

5. In a lifting jack, a supporting frame, a lifting member mounted therein, a lever pivoted to said frame, a pivot therefor, a holding dog mounted on said pivot, a lifting dog pivoted on said lever, extensions on said dogs, pins thereon, a slotted plate engaging said pins, a spring in one slot engaging the pin on the holding dog, a tension means attached to the lever to operate the plate and thereby force both dogs into engagement with the rack, and a spring between both dogs tensioned to normally separate the gripping teeth of the dogs.

In testimony whereof I have signed my name to this specification.

THOMAS J. MCCARTHY.