US1397925A - Lifting-jack - Google Patents

Description

w. c. ENGEL. LIFTING JACK.

APPLICATION FILED MAY'H. I921.

1,397,925. Patented Nov. 22, 1921.

UNITED STATES PATENT OFFICE.

WILLIAM C. EN GEL, OF ST. LOUIS, MISSOURI, ASSIGNOR OF ONE-THIRD TO EDWARD L.

HOHENSTEIN AND ONE-THIRD TO FREDERICK SCHOTT, BOTH OF ST. LOUIS, MIS- LIFTING-JACK.

Application filed May 14, 1921.

T0 aZZ NJ/Z0772 it may concern:

Be it known that I, lViLLiAM C. ENGEL, a citizen of the United States, and a resident of the city of St. Louis and State of Missouri, have invented a new and useful Improvement in Lifting-Jacks, of which the following is aspecification.

My invention relates to lifting jacks and has for its principal object to devise a jack which will lower gradually. The invention consists principally in mounting in a hollow standard, a hollow lifting post that is adapted to contain liquid and is provided with a valve at its lower end. The invention further consists in the parts and combinations of parts hereinafter described and claimed.

In the drawings which form part of this specification and wherein like reference numerals indicate like parts wherever they occur,

Figure 1 is an elevation of a jack embodying my invention;

Fig. 2 is a top plan view thereof;

Fig. 3 is a sectional view thereof on the line 3-3 in Fig. 2; and

Fig. 4 is a detail view of the lower end of the lifting post.

A hollow lifting post 1 open at the bottom is telescopically mounted in a hollow standard 2 that is closed at the bottom. Preferably the lifting post 1 is provided with a depending ratchet bar 3 that is spaced therefrom and extends parallel therewith. Vertically disposed plates 4 project from the standard 2 near the top thereof. A hand lever 5 is disposed between said plates 4 and is pivotally secured thereto. A pawl or dog 6 is pivotally secured between the bifurcated end portions 7 of said hand lever 5 in position to engage a notch of the lifting post ratchet bar 3. Secured in a notch in the lower end of said dog is one end of a spring 8, the other end of which is secured to the lever 55. This spring 8 tends to keep the dog 6 in engagement with a notch of the lifting postratchet bar 3. The movement of the dog 6 is limited by the shoulder 9 of the lever 5 that is formed by the union of the bifurcated end portions thereof. A locking pin 10 is also pivotally secured between said plates 4 above said dog 6 and in position to engage a notch of the ratchet bar 3 and prevent the lifting post 1 from lowering.

Specification of Letters Patent.

Patented Nov. 22, 1921. Serial No. 469,531.

The hollow standard 2 contains oil or other liquid. The lifting post 1 is provided with a suitable seal or packing 11 to keep the oil from filling the space between the lifting post 1 and the standard 2. A disk or valve 12 that is adapted to close the bottom of the lifting post 1 is provided with a slotted stem 13, through the slot of which extends a pin 14 that is secured in the lifting post 1. The lifting post is also adapted to contain oil or other liquid. It is provided with a small weep'hold 15 near the bottom thereof and a small air hole 16 near the top thereof.

The operation of the lifting jack is as follows:

Assuming that the lifting post is in lowered position, as shown in Fig. 3, the lifting post is filled with oil and the valve 12 hangs down, the interior of the lifting post communicating with the interior of the standard through the open end of the lifting post. The lifting post is raised by depressing the outer end of the hand lever 5, which causes the dog 6 to move upwardly, carrying the ratchet bar and lifting post upward. The locking pin 10 engages a notch of the ratchet bar 3 and prevents the post from lowering. The handle 5 is then raised, lowering the dog 6 into position to engage another notch of the ratchet bar 3. The spring 8 permits the dog 6 to give enough to clear the teeth of the ratchet bar on the downward stroke. The handle 5 is alternately raised and lowered till the lifting post is raised to the desired position. As the lifting post is raised, oil flows from it into the standard 2 and air enters the liftin post through the hole 16 near the top thereof.

ownward movement of the lifting post is grevgnted by the locking pin 10 and the When it is desired to lower the lifting post, the lever 5 is depressed far enough that the dog 6 is raised upwardly through an arc and disengages itself and the locking pin 10 from the notches of the lifting post ratchet bar 3. The lifting post then starts to settle and the valve 12 is forced against the bottom thereof, thus closing the main opening into the lifting post. The oil in the standard provides a. liquid cushion on which the post rests. Oil enters the lifting post in small quantities through the weep hole 15. Thus, as the oil gradually flows from the standard into the lifting post, the lifting post gradually settles until it reaches its lowered position.

The above described construction eliminates the necessity for operating the'lever when lowering the jack, and eliminates the danger of shocks and jars, providing an even, gradual downward movement. It is obvious that numerous changes may be made without departing from my invention and I do. not wish to be limited to the precise construction shown.

What I claim is:

1. A lifting jack comprising a hollow standard having a closed bottom, a hollow lifting post mounted to telescope therein and having its bottom open to communicate with the interior of said standard,both said standard and lifting post being adapted to contain a liquid, a valve for the bottom of said lifting post arranged to control the communication between said lifting post and standard, said lifting post being provided with a small weep hole constituting a permanently open passageway between the interior of said lift ing post and the interior of said standard.

2. A lifting jack comprising a hollow standard having a closed bottom, a hollow lifting post mounted to telescope therein and having its bottom open to communicate with the interior of said standard, both said standard and lifting post being adapted to contain a liquid, a valve arranged to control the opening between said lifting post and standard, said lifting post being provided with a small weep hole constituting a permanently open passageway between the interior of said standardand the interior of said lifting post,

and means for raising said lifting post.

3. A lifting jack comprising a hollow standard having a closed bottom, a hollow lifting post mounted to telescope therein and having its bottom open to communicate with the interior of said standard, both said standard and lifting post being adapted to contain a liquid, an oil-tight seal between said standard and lifting post, a valve arranged to control the communication between said lifting post and said standard, said lifting post being provided with a small weep hole lifting jack comprising a hollowstandard having a closed bottom, a hollow lifting post mounted to telescope therein and having its bottom open to communicate with the interior of said standard,both said standard and lifting post being adapted to contain a liquid, an oil-tight seal between said lifting post and standard, a valve arranged to open the communication between said lifting post and said standard when the lifting post is being raised and to close said communication when said lifting post is lowering, said lifting post being provided with a small weep hole constituting a permanently open passageway between the interior of said standard and the interior of said lifting post, whereby liquid may flow into said lifting post from the standard when the valve is in its closed position, and means for raising said lifting post.

5. A lifting jack comprising a hollow standard having a closed bottom, a hollow lifting post mounted to telescope therein and having its bottom open to communicate with the interior ofsaid standard, both said standard and lifting post being adapted to contain a liquid, a pin fixed in said lifting post near the bottom thereof, a valve having a slotted stem whereby it is mounted on said pin, said valve being arranged to control the communication between said lifting post and standard, said lifting post being provided with a small weep hole constituting a permanently open passageway between the interior of said lifting post and the interior of said standard, means for raising said lifting post, means for holding it in raised position and means for releasing it to permit 9 it to lower.

Signed at St. Louis, Missouri, this 12th day of May, 1921.

WILLIAM C. ENGrEL

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