US3632085A

US3632085A - Lift-all jack

Info

Publication number: US3632085A
Application number: US886547A
Authority: US
Inventors: George J Traywick
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-12-19
Filing date: 1969-12-19
Publication date: 1972-01-04
Anticipated expiration: 1989-01-04

Abstract

A lift-all jack having a generally horizontally disposed frame member with an anchor fixedly attached to one end of the frame and normally extending therefrom, an air cylinder fixedly disposed along the frame member having a stationary member horizontally attached to the frame and a reciprocating ram designed to be displaced away from the anchor member. A pair of generally parallel lifting bars pivotally connected at one end thereof to the reciprocating member and pivotally connected at the other end to a lifting cradle, a torque-holding arm pivotally connected to the lifting cradle at one end thereof and pivotally connected to the upper portion of the anchor at the other end thereof, whereby actuation of the power cylinder horizontally away from the anchor will induce a vertical movement of the lifting cradle and a load disposed thereupon. A method of lifting one end of a vehicle which will minimize lateral displacement during the operation including the steps of: pivotally holding a lifting cradle about a point remote from said cradle and at a height equal to or greater than the height desired of the lifting cradle.

Description

United States Patent Primary Examiner-Othell M. Simpson Attorney-Bums, Doane, Swecker & Mathis ABSTRACT: A lift-all jack having a generally horizontally disposed frame member with an anchor fixedly attached to one end of the frame and normally extending therefrom, an air cylinder fixedly disposed along the frame member having a stationary member horizontally attached to the frame and a reciprocating ram designed to be displaced away from the anchor member. A pair of generally parallel lifting bars pivotally connected at one end thereof to the reciprocating member and pivotally connected at the other end to a lifting cradle, a torque-holding arm pivotally connected to the lifting cradle at one end thereof and pivotally connected to the upper portion of the anchor at the other end thereof, whereby actuation of the power cylinder horizontally away from the anchor will induce a vertical movement of the lifting cradle and a load disposed thereupon.

A method of lifting one end of a vehicle which will minimize lateral displacement during the operation including the steps of: pivotally holding a lifting cradle about a point remote from said cradle and at a height equal to or greater than the height desired of the lifting cradle.

rmmzm m2 3.6321085 SHEET 1 [IF 2 IV 20 v 5 INVENTOR PATENTEU JAN 4 B72 SHEET 2 BF 2 LIFT-ALL JACK BACKGROUND OF THE INVENTION This invention relates to a lift-all jack of the type which may be used in a variety of locations but primarily in a vehicle garage or repair shop. In repairing or adjusting the various parts of an automobile it is frequently desirable to lift one end or one side of the vehicle to facilitate the operation. As an example, in front-wheel balancing operations both wheels are lifted from the ground and rapidly rotated to determine the extent of the out-of-balance present and the amount and location of weights which would bring the wheels into dynamic balance. In order to rapidly facilitate the execution of the balancing operation, or other repair procedures, it would be desirable to have a portable jack readily available.

Various types of portable lifts or jacks have been proposed for use in repair shops. Frequently, however, the previously known jacks have been designed to be engageable with the bumper of an automobile. While bumper jacks are suitable for some applications, approximately 75 percent of bumpers of present day vehicles are not designed to support the weight of an automobile in this manner. Further, when tires are balanced on the vehicle, the automobile has to be lifted by the frame.

In contrast another type of lifting device is a frame jack. Frame jacks are typically hydraulically operated by pumping a hydraulic fluid to a power cylinder. Jacks of this type often carry internally a sump of hydraulic fluid and therefore are heavy and cumbersome to accurately position under a vehicle. Further, a considerable amount of manual pumping is required with hydraulic jacks before the desired vehicle height is attained.

Some frame jacks have been designed to operate from a screw mechanism. Such lifting devices, however, are difficult and time consuming to operate, and therefore are typically not suitable for use in a repair garage where a number of vehicles are worked upon in a day.

A probelm encountered with both bumper and frame-type jacks is the tendency of the lifting pad which contacts the vehicle to be laterally displaced as it raises. Typically, this lateral displacement may be as much as 8 to 10 inches. Closely associated with the lateral displacement problem is the installable nature of most lifting devices. In this connection many previously known bumperand frame-type jacks have been supported on a four-wheeled frame to facilitate movement of the device when not in use. However, as the vehicle is lifted and laterally displaced the jack has a tendency to roll under or away from the vehicle. This propensity to roll or shift as the vehicle is being raised or even when the vehicle is in the fully elevated position, as a result of something bumping into the vehicle, presents a potential hazard to repairmen working around the lifted vehicle. Another hazard with some previously known devices is the possibility that the vehicle may unexpectedly drop from the elevated position if the lifting mechanism should fail.

It would therefore be desirable to have a frame jack which would be light and easy to manipulate, yet rapid in operation, It would further be desirable to have a frame jack that could be actuated from a power source readily accessible in repair garages. It would also be desirable to have a frame jack and method of operation which would minimize lateral displacement of the lifting cradle during the lifting operation. Also it would be desirable to minimize or eliminate the possibility of the vehicle rolling or shifting after it has been raised or elevated to a repair position and further minimize the possibility of the vehicle dropping unexpectedly from the elevated position.

OBJECTS AND SUMMARY OF THE INVENTION Objects It is therefore a general object of the invention to provide a method and apparatus for alleviating or minimizing problems of the type previously discussed.

It is a particular object of the invention to provide a method and apparatus for lifting a portion of a vehicle such as for example an automobile in a vertical manner with a minimum of lateral displacement.

It is a further object of the invention to provide a method and apparatus for lifting a portion of a vehicle, such as for example an automobile, with a readily available source of power found in most repair shops.

It is another object of the invention to provide a method and apparatus for lifting a vehicle, such as for example an automobile, with a device which may be easily transported and rapidly positioned under the frame of the vehicle.

It is still another object of the invention to provide a method and apparatus for lifting a vehicle, such as for example an automobile, in a rapid and effortless manner which will minimize or eliminate any tendency of the vehicle to roll or shift in the elevated position.

It is yet another object of the invention to provide a method and apparatus for locking the lifting device in an elevated position to minimize the possibility of an unexpected dropping of the elevated vehicle.

Brief Summary An apparatus for accomplishing at least some of the foregoing objects comprises a generally horizontally disposed frame having a vertically extending anchor member integrally attached at one end thereof. A power cylinder is longitudinally aligned with and fixedly attached to the horizontal frame and is adapted to have a ram of the power cylinder deployed away from the anchor member. A lifting cradle suitable for engagement with a frame of an automobile is connected to the ram of the power cylinder by means of a parallel linkage that is pivoted at its ends to the ram and lifting cradle. A torque-holding arm is then pivotally attached to the cradle at one end and the upper portion of the anchor at the other end, whereby a horizontal translation of the power ram will induce vertical movement of the lifting cradle.

A significant method aspect of the invention comprises positioning a lifting cradle under the frame of an automobile, holding the cradle pad about a pivot point which is remote from and generally higher than the elevation desired by the cradle pad, and horizontally moving one end of a fixed length bar under the cradle pad by pivotally applying a horizontal force to one end thereof while the other end of the fixed bar is pivotally connected to said cradle pad. Thus, the cradle pad will be raised about the pivot point with a minimum amount of lateral translation.

THE DRAWINGS A lift-all jack constructed in accordance with a preferred embodiment of the invention is illustrated in the accompanying drawings in which:

FIG. 1 is a side elevational view of a vehicle lifted by a liftall jack according to a preferred embodiment of the invention;

FIG. 2 is a side elevational view of the lift-all jack of the invention partially in cross section, disclosing the interior of the power cylinder when the lift-all jack is in the lowered position;

FIG. 3 is a side elevational view of the lift-all jack in the raised position and taken partially in section to disclose multiple apertures for locking the jack in a raised position;

FIG. 4 is a top view of the lift-all jack shown in FIG. 2;

FIG. 5 is a sectional view taken along section line 5-5 of FIG. 3, disclosing the lifting cradle mechanism in elevated position; and

FIG. 6 is a sectional view taken along section line 6-6 of FIG. 3, disclosing the locking mechanism of the invention.

DETAILED DESCRIPTION Referring to the drawings wherein like numerals designate like parts, and particularly to FIG. 1 thereof, there will be seen a vehicle I0 lifted at one end thereof by a lift-all jack 12.

The jack is provided with a generally horizontally disposed frame 14 which is supported above the surface 16 by a wheel assembly 18 positioned on both sides of the frame and a flat stabilizing pad 20. The jack frame 14 is provided at one end with a vertically extending anchor 22. The frame is further provided with a horizontally disposed power cylinder 24. A lifting cradle 26 is positioned beneath the frame of the vehicle to be lifted. The lifting cradle is connected to the power cylinder by means of parallel lifting bars 28. The lifting bars 28 are pivotally connected at their ends to a portion of the power cylinder 24 and the lifting pad 26. The lifting pad is constrained for pivotal rotation about an upper portion of the anchor 22 by a holding arm 30. The lift-all jack is further provided with a handle 32 so that an operator may manipulate the jack beneath the frame of a vehicle to be elevated.

Referring now to FIGS. 2 and 4, there will be seen a lifting jack as shown in FIG. 1 but disposed in a lowered position. The frame 14 comprises a pair of longitudinally extending generally

parallel strips

15 and 17. The

strips

15 and 17 are connected at their forward end by a stop plate 34 spanning an upper portion thereof and a stabilizing pad 36 spanning a lower portion thereof. The stabilizing pad extends beyond the frame member 14 approximately one-half the width of the frame member on each side of the frame. This lateral extension on the stabilizing pad 36 provides a dimension of stability not encountered in previously known devices.

The frame 14, as previously discussed, is provided with a pair of wheel assemblies 18 journaled for rotation one each on the lateral surfaces of the

frame strips

15 and 17. The wheel assemblies are positioned slightly to the left, as viewed in FIG. 2, of the center of gravity of the lift-all jack such that the jack pivots about the wheel fulcrum in a clockwise direction and the pad 36 normally rests on the ground. An operator, however, may easily tilt the jack about the wheel fulcrum by applying downward leverage to the handle 32, to effortlessly manipulate the lift-alljack under the frame of an automobile.

The frame 14 is further provided at the rearward portion thereof with a normally extending anchor member 22. The rearward anchor 22 is composed of normally extending members 23 and 25 which are integral with the

frame strips

15 and 17 respectively and extend to a height at least equal to but preferably greater than the maximum lifting height of the eradle pad for reasons which will be discussed hereinafter.

Fixedly positioned in a longitudinal manner along the frame member 14 is a power cylinder 24. The power cylinder 24 is provided with a cylindrical casing 38 which is fixedly attached as by welding between the parallel frame strips 15 and 17, as best seen in FIGS. 2 and 4. A power ram 40 is positioned for longitudinal reciprocation within the cylindrical casing 38.

An air line 50 is connected to a source of compressed air (not shown), which is readily available in most garages and repair shops, and leads into a two-way air valve48 connected to the base of the anchor 22. The valve 48 is designed to feed compressed air from line 50 into line 51 or connect line 51 with the atmosphere. Separate air valves for admission to and exhaust of air from the cylinder may be used if desired.

The power ram 40 is provided at the rearward end thereof with a cylinder head 42 designed to reciprocate in intimate sliding contact along the inner cylindrical surface of the cylindrical casing 38. The head 42 is provided at a lateral mid portion thereof with a circumferential O-ring 44 or other suitable sealing devices such as pliable leathers.

The air line 51 extends downstream of the two-way valve 48 and through the end wall 46 of the cylindrical casing 38. Thus, a source of compressed air may be connected with the power cylinder 24 for driving the ram 40 horizontally away from the anchor 22.

A pair of parallel lifting bars 28 are pivotally connected on both sides of the power ram 40, as best seen in FIGS. 2-5, by transversely extending

pin connections

52, 53.

At the opposite ends of both sets of parallel lifting bars 28 a lifting cradle 26 is provided which is pivotally connected to the lifting bars 28 by

pin bearings

54 and 55.

The rearward pin connection 53, as best seen in FIG. 5, extends beyond the width of the lifting bars 28 and serves as a suitable connecting means for a pair of return springs 58, which extend longitudinally along the power cylinder. The other ends of return springs 58 are fixedly attached to a pair of taps 60, as best seen in FIGS. 3 and 4.

Referring to FIG. 5, the interior walls of the frame strips 15 and 17 are provided with L-shaped running platforms 63. The forward end of the translating power ram 40 is provided with a pair of wheels 65 journaled for rotation about the lateral faces of a lower portion of the forward end of the power ram 40. These rollers are designed to ride upon the running platforms 63. Thus, the power ram is supported for longitudinal translation along the frame member 14.

As best seen in FIGS. 2 and 3, the lifting cradle 26 is constrained to pivot about an uppermost portion of the anchor 22 by a torque-holding arm 30. The torque-holding arm is pivotally connected at its opposite ends first to the lifting cradle through the pin bearing 54, as best seen in FIG. 5, and at its opposite end to a pin bearing connection 67 at the uppermost portion of the anchor 22.

The torque-holding arm 30 is composed of three

segments

68, 69 and 70 which are integrally connected at an angle with respect to each other, so that in the lower position, as shown in FIG. 2, the torque-holding arm 30 will conform to the dimensions of the horizontally disposed frame and power ram so that the jack may be easily positioned beneath the frame of a lowlying vehicle.

Referring to FIGS. 3 and 6, there will be seen a locking mechanism 70 which comprises a longitudinally extending rod which runs through a pair of bearing collars 72 and a has a normally extending handle 74 positioned adjacent the anchor 22. The opposite end of the rod 71 is provided with a normally extending segment 76, as best seen in FIG. 6. Normally disposed and connected to the segment 76 is a lockpin 78 which extends through an aperture 80 in the frame strip 17 and through one of a plurality of apertures 82 in the translating power ram 40. Thus, it can be seen that when the jack mechanism is raised to the desired elevation, the lock handle 74 may be rotated to withdraw the locking pin 78 from contact with the power ram until a selected aperture, corresponding to a desired height of the cradle 26, is aligned with the axis of the aperture 80 in the frame strip 17. When alignment is obtained, the handle may be rotated in the opposite direction to engage the locking pin 78 with the desired aperture, and thus the lifting mechanism is locked at the desired height to prevent unexpected dropping of the elevated vehicle if the pressure system should fail.

The Method When it is desired to raise a vehicle, such as an automobile, for balancing the front tires or making other repairs, the forward portion of the lift-all jack 12 is positioned until the cradle pad 26 lies beneath the frame of the automobile. The air line 50 is then connected to an air compressor and the two-way valve 48 is actuated to deliver air to the power cylinder 24. The ram 40 is then forced in a horizontal direction away from the anchor 22, riding at its outer end on running platforms 63. The parallel lifting bars 28 pivotally connected to the power cylinder and the lifting cradle simultaneously rise. The lifting cradle pivotally connected to the anchor by the fixed link torque arm 30 therefore pivots upwardly. The parallel lifting arms 28 rise at an identical angle and therefore the upper portion of the lifting cradle 26 is retained in a horizontal posture throughout the lifting operation.

If it is desired to utilize the maximum vertical lift of the jack, the ram will be pressurized until it reaches the crossing plate or stop member 34, as best seen in FIG. 3. The lock mechanism is then rotated into position at the furthermost aperture 82 in the translating ram which will be in register with the fixed aperture in the frame 17. The two-way valve may then be positioned in a neutral position and the automobile is ready to be worked upon or repaired. It will be realized that the lateral extent of the stabilizing pad 36 will prevent a tendency for the automobile to tilt while it is in the erected position and further rolling of the vehicle in the lifted position will be minimized.

The remote pivot point 67 of the anchor 22 is higher than the maximum lift of the cradle pad. The cradle will pivot about this relatively long pivot arm in a small arc and assume a practically vertical ascent. It will be realized, however, that there will be a slight amount of extension toward the vehicle and away from the anchor as the cradle pad is raised in this small arc. It should be noted, however, that the vehicle is pivoted about the rear axis and therefore there is a slight amount of withdrawal of the frame portion of the automobile from the jack mechanism as it follows an are having an axis through the rear axis of the automobile. In other words the jack extends toward the automobile and away from the anchor while the automobile extends slightly away from the anchor. Thus, the tendency of the vehicle to be laterally displaced as it raises is minimized.

When it is desired to lower the vehicle, the power cylinder is repressurized by rotation of the two-way valve, so that the lockpin 78 may be disengaged from the aperture 82 in the power ram 40. The two-way valve is then positioned to open the interior of the air cylinder to the atmosphere and the vehicle is quickly lowered. The lifting cradle 26 is fully disposed in its lowermost position by the action of the return springs 58 positioned on either side of the jack. The jack is then ready for another lifting operation.

It will be appreciated that the invention as described above in connection with a preferred embodiment thereof is easily manipulated by an operator and will rapidly operate from a compressed air source which is standard in most repair shops. The lifting jack is stable in the lifted position by means of the laterally extending stabilizing pads 36 and the absence of rollers.

Lateral displacement of the vehicle during raising is avoided by the use of a pivot higher than the extent to which the jack may be raised. Further, the jack may be locked in a raised position so as to eliminate the possibility of the jack accidentally descending while repairs upon the automobile are taking place.

Although the invention has been described with reference to a preferred embodiment, it will be appreciated that additions, deletions, substitutions and modifications, and other changes not specifically disclosed or described, may be made which will fall within the purview of the appended claims.

What is claimed is: 1. An airjack comprising: a frame member; an anchor fixedly attached to said frame member at one end thereof and generally normally extending with respect thereto; an air cylinder having a stationary member fixedly attached to said frame member, and

a reciprocating member, designed for displacement away from said anchor when the jack is being raised and toward said anchor when the jack is being lowered;

a lifting cradle;

a pair of generally parallel cradle lifting bars each being pivotally connected to the reciprocating portion of said air cylinder at one end thereof and pivotally connected to said lifting cradle at the other end thereof; and

a torque-holding arm pivotally connected to said lifting cradle at one end thereof and pivotally connected to said anchor at the other end thereof, whereby actuation of said power cylinder horizontally away from said anchor will induce a vertical movement of said lifting cradle while simultaneously maintaining the cradle in a generally horizontal posture.

2. An air jack as defined in claim 1 wherein:

said torque-holding arm is pivotally connected to said anchor at an uppermost position thereupon whereby the height of said pivot is greater than or equal to the operating height of said lifting cradle.

3. An airjack as defined in claim 1 wherein: said reciprocating member is provided with roller means journaled thereto for supporting said reciprocating member in translation upon said frame member. 4. An air ack as defined rn clarm l and further comprising:

a stop member positioned upon said frame remotely from said anchor for limiting the extension of said reciprocating member.

5. An airjack as defined in claim 1 and further comprising:

a jack-stabilizing pad fixedly connected to the underside of the end of the frame remote from said anchor.

6. An airjack as defined in claim 5 wherein:

said jack stabilizing pad is approximately twice as wide as said jack frame to minimize tilting of the object being lifted.

7. An air jack as defined in claim 5 and further comprising:

roller means journaled onto said frame at a position intermediate the ends thereof for facilitating transportation of said air jack and for combining with said jack stabilizing pad to provide a firm bearing arrangement when the jack is being utilized.

8. An air jack as defined in claim 1 and further comprising:

lock means engageable with both said frame and said reciprocating member of said air cylinder for selectively locking said reciprocating member to said frame.

9. An air jack as defined in claim 8 wherein:

said reciprocating member is provided with a plurality of longitudinally aligned apertures and said frame is provided with a compatibly dimensioned aperture positioned such that as the reciprocating member is extended said plurality of longitudinally aligned apertures progressively pass in registry with the aperture in said frame.

10. An air jack as defined in claim 9 wherein said lock means comprises:

a rod running along said frame from a position adjacent the aperture in said frame to a position near the anchor end of said frame, said rod having adjacent said aperture a first normally extending leg and a second leg normally extending with respect to said first leg and adapted to be positioned through the aperture in said frame and a selected aperture in said reciprocating member whereby said reciprocating member may be selectively locked to said frame.

11. An airjack as defined in claim 1 wherein:

said torque-holding arm is provided with a double bend intermediate the ends thereof whereby said air jack may be positioned under low-lying objects.

12. An air jack as defined in claim 1 and further comprising:

spring return means for retracting said reciprocating member within said stationary member when it is desired to lower said air jack.

13. An airjack as defined in claim 1 and further comprising:

a two-way valve connected to said anchor for selectively admitting air to said air cylinder for raising and lowering said air jack.

14. An air jack lifting mechanism comprising:

an anchor member extending generally vertical to the horizontal;

a generally horizontal torque-holding arm pivotally connected to the upper end of said anchor member;

an air cylinder fixedly connected in a horizontal position against rotation to the bottom of said anchor and having a piston therein for air pressure actuated movement away from said anchor in a generally horizontal direction;

a lifting arm pivotally connected to said piston; and

a cradle pad pivotally connected to both said torque-holding arm and said lifting arm whereby actuation of said air cylinder induces upward movement of said cradle pad with a small component of movement away from said anchor member.

Claims

1. An air jack comprising: a frame member; an anchor fixedly attached to said frame member at one end thereof and generally normally extending with respect thereto; an air cylinder having a stationary member fixedly attached to said frame member, and a reciprocating member, designed for displacement away from said anchor when the jack is being raised and toward said anchor when the jack is being lowered; a lifting cradle; a pair of generally parallel cradle lifting bars each being pivotally connected to the reciprocating portion of said air cylinder at one end thereof and pivotally connected to said lifting cradle at the other end thereof; and a torque-holding arm pivotally connected to said lifting cradle at one end thereof and pivotally connected to said anchor at the other end thereof, whereby actuation of said power cylinder horizontally away from said anchor will induce a vertical movement of said lifting cradle while simultaneously maintaining the cradle in a generally horizontal posture.

2. An air jack as defined in claim 1 wherein: said torque-holding arm is pivotally connected to said anchor at an uppermost position thereupon whereby the height of said pivot is greater than or equal to the operating height of said lifting cradle.

3. An air jack as defined in claim 1 wherein: said reciprocating member is provided with roller means journaled thereto for supporting said reciprocating member in translation upon said frame member.

4. An air jack as defined in claim 1 and further comprising: a stop member positioned upon said frame remotely from said anchor for limiting the extension of said reciprocating member.

5. An air jack as defined in claim 1 and further comprising: a jack-stabilizing pad fixedly connected to the underside of the end of the frame remote from said anchor.

6. An air jack as defined in claim 5 wherein: said jack stabilizing pad is approximately twice as wide as said jack frame to minimize tilting of the object being lifted.

7. An air jack as defined in claim 5 and further comprising: roller means journaled onto said frame at a position intermediate the ends thereof for facilitating transportation of said air jack and for combining with said jack stabilizing pad to provide a firm bearing arrangement when the jack is being utilized.

8. An air jack as defined in claim 1 and further comprising: lock means engageable with both said frame and said reciprocating member of said air cylinder for selectively locking said reciprocating member to said frame.

9. An air jack as defined in claim 8 wherein: said reciprocating member is provided with a plurality of longitudinally aligned apertures and said frame is provided with a compatibly dimensioned aperture positioned such that as the reciprocating member is extended said plurality of longitudinally aligned apertures progressively pass in registry with the aperture in said frame.

10. An air jack as defined in claim 9 wherein said lock means comprises: a rod running along said frame from a position adjacent the aperture in said frame to a position near the anchor end of said frame, said rod having adjacent said aperture a first normally extending leg and a second leg normally extending with respect to said first leg and adapted to be positioned through the aperture in said frame and a selected aperture in said reciprocatiNg member whereby said reciprocating member may be selectively locked to said frame.

11. An air jack as defined in claim 1 wherein: said torque-holding arm is provided with a double bend intermediate the ends thereof whereby said air jack may be positioned under low-lying objects.

12. An air jack as defined in claim 1 and further comprising: spring return means for retracting said reciprocating member within said stationary member when it is desired to lower said air jack.

13. An air jack as defined in claim 1 and further comprising: a two-way valve connected to said anchor for selectively admitting air to said air cylinder for raising and lowering said air jack.

14. An air jack lifting mechanism comprising: an anchor member extending generally vertical to the horizontal; a generally horizontal torque-holding arm pivotally connected to the upper end of said anchor member; an air cylinder fixedly connected in a horizontal position against rotation to the bottom of said anchor and having a piston therein for air pressure actuated movement away from said anchor in a generally horizontal direction; a lifting arm pivotally connected to said piston; and a cradle pad pivotally connected to both said torque-holding arm and said lifting arm whereby actuation of said air cylinder induces upward movement of said cradle pad with a small component of movement away from said anchor member.