US3007676A

US3007676A - Energy-recuperating lifting jack

Info

Publication number: US3007676A
Application number: US858512A
Authority: US
Inventors: Javorik Laszlo
Original assignee: ADDISON W ARTHURS
Current assignee: ADDISON W ARTHURS
Priority date: 1959-12-09
Filing date: 1959-12-09
Publication date: 1961-11-07
Anticipated expiration: 1978-11-07

Description

Nov. 7, 1961 L. JAVOIRIK ENERGY'RECUPERATING LIIFTING JACK Filed Dec. 9, 1959 Fig.1

2 Sheets-Sheet 1 F ig 2 Fig? INVENTOR. Lasz/o Javorilr HIS ATTORNEY$ Nov. 7, 1961 JAVORIK 3,007,676

ENERGY-RECUPERATING LIFTING JACK Filed Dec. 9, 1959 2 Sheets-Sheet 2 a K INVENTQR. F g; 5 Lasz/o Javonk BY HIS ATTORNEYS United States Patent 3,007,676 ENERGY-RECUPERATING LIFIING JACK Laszl Javorik, 378 N. Hamlin St., Chicago 24, Ill.,

assignor of one-half to Addison W. Arthurs, Pittsburgh, Pa. I

Filed Dec. 9, 1959, Ser. No. 858,512 3 Claims. (Cl. 254-1) This invention relates to an energy-recuperating lifting jack comprising an elevating member and springs connected to the elevating member and adapted to be compressed upon lowering of the elevating member, and means for releasably holding the elevating member against the action of the spring. The energy-recuperating jack may be loaded in any convenient place, such as a garage of -a home, by compressing the springs to store energy in them. The elevating member of the energy-recuperating jack is held in lowered position by some suitable means, such as a detent, after the spring is loaded. The loaded energy-recuperating jack may then be carried in the automobile and is available for use on the road. In changing a tire, for instance, the loaded energy-recuperating lifting jack is placed under the car and the detent, which holds down the elevating member, is released, whereupon the springs which have been loaded previously expand and supply their energy for raising the automobile.

The energy-recuperating lifting jack of the present invention can be used for any purpose in which the jack is loaded in a previous operation and the energy of the loaded jack is employed in a subsequent operation.

In the accompanying drawings which illustrate two embodiments of my invention;

FIGURE 1 is a vertical section of one embodiment showing the elevating member of the jack in raised position;

FIGURE 2 is a view similar to FIGURE 1 except that it shows the elevating member in lowered position and the springs compressed;

FIGURE 3 is a vertical section taken on the line IIIIII of FIGURE 2;

FIGURE 4 is a front elevation of another embodiment of the invention showing the elevating member in lowered position; and

FIGURE 5 is a vertical section taken on the line VV of FIGURE 4.

Referring more particularly to the accompanying drawings and for the present to the embodiment shown in FIGURES 1, 2 and 3, the energy-recuperating jack comprises a base 2 and an upwardly extending guide 4 secured at its lower end to the base. This guide may be in the form of a tube. A rack bar 6 having a lifting head 8 at its upper end has its lower part slidably received in the guide 4. The rack bar is provided with teeth 10 which are accessible from the outside of the guide 4 due to the provision of a suitable slot 11 in the guide.

Two springs indicated generally by

reference numerals

12 and 14 are provided, each of which is pivotally connected by a pin 16 to a plate 18 secured to the base 2 and pivotally connected by a pin 20 to a plate 22 secured to the rack bar 6. The plate 22 extends through slots 24 formed in the guide 4 so that the rack bar 6 can move upwardly and downwardly in the guide. Each of the

springs

12 and 14 is made of alternate rubber discs 26 and steel discs 28 secured by any suitable means or by vulcanization, such as a suitable cement. Since the springs act almost entirely in compression, a strong bond is not required between the rubber discs and the steel discs.

A detent 30 is pivotally mounted by a pin 32 on lugs 34 secured to the guide 4. The lower end 35 of the detent extends into slot 11 and is caused to engage the teeth 10 of the rack bar 6 by means of a compression spring 36 3,007,676 Patented Nov. 7., 1961 connected to the upper end 38 of the detent and to the guide 4.

i A lever '40, which, in the form illustrated, is a socket for receiving an extention bar, is pivotally mounted by a pin 42 to lugs 44 secured to the guide 4. A pawl 46 is pivotally connected by a pin 48 to a lug 46a on the lower side of thelever 40. A spring 50 is connected to the lever 40' and to the upper end. 52 of the pawl 46. The lower end 54 of the pawl can be brought into engagement with the teeth 10 of the rack bar 6 and upon rotation of the lever 40 in a clockwise direction as viewed in FIG- URE 3, the rack bar 6 can be lowered a further amount and the

springs

12 and 14 can be compressed to a further extent than that obtained by applying a weight to the lifting head 8 if that is required.

A projection 56 is secured to the upper side of. the lever 40with the upper end of the projection in a position to contact the detent 30 and release it from the teeth 10 when the lever '40 is rotated counterclockwise from the position shown in FIGURE 3.

In preparing the jack for use, it is preloaded by applying a downward force on the lifting head 8, thereby lowering the rack bar 6 and compressing the

springs

12 and 14. The rack bar is held in its lowered position by the detent 30. When it is desired to use the preloaded jack in lifting a weight, the head 8 is placed under the weight to be lifted and the lever 40 is rotated counterclockwise so that the projection 56 engages the detent 30, thereby releasing it. The pawl 46 also is released from teeth 10, whereupon the springs 12 and 1 4 expand to raise the rack bar 6.

Referring now to the embodiment shown in FIGURES 4 and 5, the jack comprises a base 60 to which is secured a guide 62 in the form of a tube. The guide 62 slidably receives a rack bar 64 having a lifting head 66 secured to it.

The upper ends of each of two links 68 are pivotally connected by pins 70 to the lifting head 66 and the lower ends of each of two links 72 are pivotally connected by pins 74 to the base 60. The adjacent ends of the

links

68 and 72 are pivotally connected by pins 76 to spring plates 78. Steel coil springs 80 are interposed between the plates 78 and plates 82 which are secured to the upturned ends 84 of the base 60. The ends of the springs fit into retaining rings 85 secured to the

plates

78 and 82. The

links

68 and 72 form two linkages located on opposite sides of the rack bar 64 and the springs 80 exert their pressure at the knees of the linkages formed by the pins 76. Two bumpers 86 are secured to the guide 62 to limit inward movement of the linkages when the springs 80 are allowed to expand. As shown in FIGURE 4, the

links

68 and 72 extend at an angle to the vertical of about 45 degrees. When the springs are allowed to expand, the links 68 are limited in their inward movement by the bumpers 86 and at this position the links 68 extend at an angle of about 10 degrees to the vertical. Thus, the working range of the linkages is within a range of from about 10 to 45 degrees with respect to the vertical. When the linkages and springs are in the position shown in FIG- URE 4, Le, the links 68 are at an angle of about 45 degrees to the vertical, the springs 80 exert a powerful force since they are greatly compressed but the moment arm through which the springs exert their force is relatively small whereas when the links '68 have moved to their innermost position, i.e., the links extend at an angle of about 10 degrees to the vertical, the spring force is less but the moment arm is greater and, on the other hand, the moment arm of the load is less. Thus, the upward force applied by the springs to the lifting head 66 is substantially constant throughout the working range of the springs.

The remaining construction of the jack shown in FIG- URES 4 and 5 is the same as that shown in FIGURES 1-3. It has a lever 90 similar to the lever 40, a projection 92 similar to the projection 56, a pawl 94 similar to the pawl 46 and a detent 96 similar to the detent 30 together with a spring 98 similar to the spring 50 and a spring 100 similar to the spring '36. The embodiment shown in FIGURES 4 and 5 is used substantially in the same manner as the embodiment shown in FIGURES 13 In each of the embodiments, the pawl 46 shown in FIGURE 3 and the pawl 94 shown in FIGURE 5 can be dispensed with in those cases where it is not desired to provide means for compressing the

springs

12 and 14 or the springs 80 to an extent beyond that which is obtained by applying a force or weight to the lifting heads 8 or 66.

The invention is not limited to the preferred embodiments but may be otherwise embodied or practiced within the scope of the following claims.

I claim:

1. An energy-recuperating jack comprising a base, a guide secured to and extending upwardly from said base, a rack slidable in said guide and having a lifting head, toggle linkages located at opposite sides of said rack and comprising pairs of links pivotally connected to each other to form knees, each of said linkages being pivotally connected at one end to said base and at its opposite end to said lifting head, springs connected to said base and pivotally connected to each of said linkages at said knees and arranged to exert an upward component of force on said rack when they are compressed, and a detent pivoted to said guide and adapted to engage said rack to prevent it from rising under the action of said springs.

2. A jack according to claim 1, wherein said springs are steel springs.

3. A jack according to claim 2, wherein said links in operation move between an angle of about 10 degrees and an angle of about degrees to the vertical.

References Cited in the file of this patent UNITED STATES PATENTS 727,192 Payne May 5, 1903 FOREIGN PATENTS 3,306 Great Britain 1908 208,023 Great Britain Dec. 13, 1923