US 3568979 A
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United States Patent LeoJ.Notenboom 121 Lake St. South, Kirkland, Wash. 98033  AppLNo. 812,272
 Filed Apr. 1, 1969  Patented Mar. 9, 1971  Inventor  FLOOR JACK MECHANISM  References Cited UNITED STATES PATENTS 1,584,178 5/1926 Littlejohn 254/114 3,131,928 5/1964 Whipple 254/116X Primary Examiner-Robert C. Riordon Assistant ExaminerDavid R. Melton Attorney-Seed, Berry & Dowrey ABSTRACT: A jack mechanism is: disclosed for use with wheeled vehicles to transfer the weight of the vehicle from the wheels to the jack. A support leg telescopes from a barrel frame to the ground. The leg is raised and lowered by a foot operated lever arm pivotally attached to the barrel and attached to the leg by a compression member. The lever arm acts against the force of a spring interposed between the leg and barrel to lower the leg. The spring aids in raising the leg.
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PATENTED MAR 9 I971 SHEET 1 OF 2 T Til. 2 pr r u I l!|\ LEO J. NOTENBOOM ATTORNEYS PATENTED AR SIB?! 3568879 SHEET 2 [1F 2 LEO J. nofsuaoou INVENTOR.
ATTORNEYS l FLOOR JACK MECHANISM BACKGROUND OF THE INVENTION The present invention relates generally to jack mechanisms used with wheeled vehicles to transfer the weight of the vehicle from the wheels to the jack. Specifically the jacks are used with hydraulic-powered mobile lifts. The jacks are placed at each corner of the base of the lift. Once the lift is moved on its wheels to a desired location the jacks are lowered to stabilize and prevent movement of the lift. The jacks can be made adjustable to compensate for uneven surfaces.
The jack mechanism *(hereinafter called a jack) is intended generally foruse in groups of two or four. Jacks are commonly attached to the four corners of a vehicle near the wheels. The I weight of the vehicle is transferred from the wheel to the jack by elevating the vehicle off its wheel with the jack. The weight transfer is accomplished by stepping on the actuating means of the jack. When not in use the support plate of the jack is raised upward, thereby not impeding the normal mobility of the vehicle. The jack incorporates features which make it especially suited for stabilizing a vehicle over irregularly shaped terrain.
An object of the present invention is an improved jack mechanism. Specifically, it is an object to improve the versatility of jack mechanisms and simplify their operation and structure. The simplified and versatile floor jack of the present invention has a telescoping leg which is raised and lowered by a foot operated actuating means. The actuating means comprises a lever arm pivotally connected to a barrel from which the leg telescopically extends, and a compression arm attached at one end to the upper end of the leg extending through the barreland at the other end at a point about onethird of the length of the lever arm from its pivot point. The lever arm lowers the leg and compresses a coil spring interposed between the upper end of the barrel and upper end of the leg when stepped on by the operator. To raise the leg, the operators lifts the lever arm with the toe of his foot. The coil spring assists the return of the leg to its raised position. The coil spring retracts the leg to a position well away from the supporting terrain.
A support plate attached to the lower endof the leg of jack is permitted to swivel to adjust the footing to accommodate irregular terrain. In one embodiment the distance the leg extends from the barrel can be varied.
It is a further object of the present invention to construct a jack having means easily engaged by an operators foot for both lowering and raising a floor plate attached to the leg .of the jack.
Still another object of the present invention is to devise means for transferring rotary motion of the actuating means into linear motion of the leg.
Yet another object is to provide means for locking the leg in its extended position.
The foregoing objects are accomplished in part by linking the lever arm to the leg with a compression member attached at one end to an elbow on the lever arm and at the other end to a cap secured to the top end of the leg. A coil spring is interposed between the top of the barrel and the cap.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front elevation view of the jack with the telescoping leg and actuating means shown in lower position with the upper position shown in phantom;
FIG. 2 is a side elevation view of the jack in FIG. 1, again with the upper position of the actuating means shown in phantom,
FIG. 3 is a side elevation view of another embodiment of the jack having means for adjusting the elevation of the telescoping leg and illustrating the actuating means in lower position by solid lines and the upper position of the actuating means in phantom; and
FIG. 4 is a side elevational view of a typical mobile lift employing jacks described herein.
DESCRIPTION OF THEINVEN'IION Referring first to FIG. 4 the jack of this invention is particularly useful with hydraulic-powered mobilelifts such as shown by reference numeral 40. A jack is mounted at each corner of the lift. The legs of the jacks are extendable an amount sufficient to raise the lift off its wheels and thereby stabilize it against movement. The body or frame of the jack is secured'to a support on the lift.
Jack 1 has barrel 2 which serves as a frame for the jack structure. Barrel 2 is made from anappropriate metal tube of generally circular cross section. Its particular shape is not critical, however, and canbe made in the form of a U-channel, for example. The principal function of the barrel is to provide a means of holding the telescoping leg 3 for sliding movement relative to the barrel. Leg 3 is a circular rod or hollow tube having a smaller diameter than a barrelto permit it to slidably fit within the barrel. The leg and barrel, as well as other parts of the jack, are constructed of materialswhich have the necessary structural strength to accommodate the weight of the vehicle or other means to which it is connected. The leg may have a rectangular or other noncircular cross section when the barrel 2 is made in the form of a U-channel or other noncircular cross section member.
Cap 4 is welded or otherwise rigidly connected to the top of leg 3. Its diameter is greater than that of barrel 2 in order to limit the downward movement of the leg relative to the barrel. Coil spring 7 is inserted over the upper end of the leg and positioned between cap 4 and barrel 2 such that it undergoes compression whenthe leg is forced downward. The coil spring is shown compressed by solid lines and expanded by phantom lines in FIGS. 1 and 2. The coil spring biases the leg to urge it to its upper position shown in phantom in the FIGS. 1 to 3'.
The jack actuating means includes throw arm8 and compression arm 9. The throw arm 8 is made from left and right plates 10 and 11 which straddle the barrel. The plates are substantially identical and bend outward. at elbow l4. Elbows l4? enable the throw arm to project outwardly from the leg 3 when the throw arm is in its lower position as shown in FIGS. l and 2, thereby enabling the jack to be locked in position.
The left and right plates 10 and II are pivotally connected to the barrel on opposite sides thereof by anchor bolts 15 and 16 to anchor plates 17 and 18. Anchor plates 17 and 18 are rigidly attached to bracket 25 which is rigidly secured to barrel 2;.
Foot pedal 13 is rigidly connected to the throw arm at its outer end between the ends of the plates 10 and 11. The pedal is a bar 13 welded to plates 10 and 11 and protrudes beyond plate 11 to enable an operator to engage the actuating means with his foot. Pedal 13 is used to lower leg 3. Pedal 28, shown in FIG. 2, is used to raise leg 3. Pedal 28 is welded to the end of member 27. Member 27 is turn welded to throw arm plate 11. Pushing downward on pedal 28 forces the throw arm away from leg 3 allowing the coil spring to retract the leg to its upward position.
Compression arm 9is made from left and right plates 22 and 23 which straddle the barrel. The lower ends of plates 22 and 23 are pivotally connected to the throw arm plates at elbows M. The upper end of the plates 22 and 23 are pivotally connected to opposite sides of cap 4. Shoulder bolts 24 provide the pivotal connections of the compression arms plates at the elbows and cap.
A force applied to pedal .13 is its upper position by an operators foot or other means operates to compress coil spring 7. Anchor bolts 15 and 16 comprise the fulcrum for the throw arm. The distance between elbow l4 and bolts 15 and 16 constitutes the lever arm for applying force to compression arm 9. As pedal 13 is pushed in a downward direction elbows l4 rotate about the pivot point where the throw arm plates 10. and ill are pivotally attached to the anchor plates 17 and 13. The throw arm plates are offset from a straight line a sufficient amount to enable the compression arm to reach its vertical locking position when or before pedal 13 abuts leg 3.
Anchor plates 17 and 18 are rigidly connected by a weld or other suitable means to bracket 25. Bracket is in turn welded to the barrel giving rigidity to the jack structure. Bracket 25 is also connected to the frame of carriage or mobile lift represented by box beam 26.
Support plate 29 is connected at the lower end of the leg 3. The support plate and the rigidity of the jack stabilize the wheeled carriage. When the leg of the jack is extended downward the weight of the carriage is transferred from the wheels of the carriage to the jack. Alternately, the carriage may be supported by suitable supports and casters provided on the support plates of the jacks. The support plate on the jack is loosely connected to the leg to-enable it to swivel about the leg. The support plate can be attached to the leg by a ball joint to permit universal pivoting. This feature gives greater versatility in adapting the jack to irregular terrain.
Another embodiment of the present jack is shown in FIG. 3. Parts common in the three FIGS. are assigned the same reference numerals. Jack 31 in FIG. 3 is the same as the jack in FIGS. 1 and 2 but includes a threaded extension 32, crank 33 and bridge 35. Cap 34 differs from cap 4 in that it is internally threaded to mate with the threads on extension 32, crank Extension 32 is rigidly connected to leg 3 and is used to raise and lower leg 3 relative to barrel 2. Bridge 35 is welded to compression arm plates 22 and 23 to give structural stability to the jack during rotation of the crank.
Both jacks l and 31 operate in a similar manner. Leg 3 is lowered into contact with the terrain supporting the carriage by engaging foot pedal 13 and rotating throw arm 8 from its upward position to its downward position. Compression arm 9 is pulled downward as the throw arm rotates. Coil spring 7 is compressed during the downward movement of the leg. The leg is locked in its downward position when compression arm 9 is in the position shown in FIGS. 2 and 3 or rotated from vertical toward anchor bracket 25. The elbows 14 of the throw arm enable the compression arm to reach a locking position before foot pedal 13 abuts the leg. The projection of the foot pedal permit easy engagement of the throw arm for raising the leg by the operators foot. To raise leg 3 to its upper position, pedal 13 is engaged and pulled out of contact with the extended leg. The coil spring assists in returning the leg to its upper position.
The invention has been clearly explained. Changes in detail of construction may be resorted to without departing from the spirit of the invention and it is accordingly my intention that no limitations be implied and that the annexed claims be given the broadest interpretation to which the employed language fairly admits.
E. A jack comprising:
a barrel having anchor means for coupling to an external apparatus;
a leg slidably mounted within said barrel;
a cap rigidly attached to said leg near the upper end thereof;
bias means disposed between said cap and barrel for urging said leg upward relative to said barrel;
a throw arm pivotally coupled to said barrel for rotational movement about its pivot point between an upper and lower position; and
a compression arm pivotally attached at one end to said cap and pivotally attached at the other end to said throw arm at a point removed from the throw arm pivot point wherein movement of said throw arm to its lower position causes said compression arm to act against said bias means, moving said leg to a lower position, and wherein movement of said throw arm to its upper position moves said leg to its upper position.
2. The jack of claim 1 further including adjustment means attached to said cap and leg for varying the lower position of said leg relative to said barrel.
3. The jack of claim 2 wherein said adjustment means includes a threaded extension member rigidly coupled to said leg mating with a threaded bore in said cap, and crank means attached to said extension for rotating said extension to raise and lower said leg relative to said cap.
4. The jack of claim 1 wherein said throw ann includes left and right arm throw plates pivotally attached at one end to opposite sides of said barrel and having angled elbows between the ends thereof, and
wherein said compression arm includes left and right compression arm plates pivotally attached at one end to opposite sides of said cap and pivotally attached at the other end to said elbows.
5. The jack of claim 4 wherein said throw arm further includes a first foot pedal attached between said throw arm plates near the outer ends thereof, the pedal extending beyond at least one of said plates providing a surface for engaging the throw arm to move the leg between its upper and lower positions.
6. The jack of claim 5 including a second foot pedal coupled to said throw arm positioned to cause movement of the throw arm to its upper position when the throw arm is in its lower position.
7. The jack of claim 6 further including means near the lower end of said leg for attaching a floor abutting apparatus such as floor plates, casters and the like.
8. The jack of claim 7 wherein said floor abutting apparatus includes a support plate attached to the lower end of said leg by universal ball joint coupling means enabling said support plate to be positioned at varying angles relative to said leg as required by the terrain.