US1228015A - Lifting-jack. - Google Patents

Description

qwm /2 0. GATES -& H. A; SMITH.

LIFTING JACK.

I APPLICATION FILED APR. 25,1915.

15. v v Patented-May 29, 1917.

avummtol/ 0- 42666 Hfl oWuZZJ OLUS GATES AND HOWARD A. SMITH, 0F ARNOLDS PARK, IOWA; SAID GATES ASSIGN'OR TO SAID SMITH.

LIFTING-JACK.

Application filed April 25, 1916.- Serial No. 93,450.

To all whom it may concern:

Be it known that we, OLUS GATES and HOWARD A. SMITH, citizens of the United States, residing at Arnolds Park, -in the county of Dickinson and State-of Iowa, have invented certain new and useful In provements in Lifting-Jacks, of which the following is a specification.

This invention contemplates an improved lifting jack and has as its primary object to provide a device of this character which may be easily and quickly adjusted and wherein the leverage of the jack may be varied according to the weight of the load.

The invention has as a further object to provide a jack normally adapted to engage the load at various elevations to thus reduce to a minimum, the necessity for the initial adjustment of the jack; 1

The invention has as a further object to provide a jack of thischaracter wherein the speed at which the load is lifted may be varied. v

And a still further obj ect of the invention is to provide a simple and efficient operating lever for the jack having pawls normally gravitating to engage coacting sections of the jack so that the said pawls will automatically act to extend the jack upon the actuation of the said lever.

Other and incidental objects will appear as the description proceeds and in the drawings wherein we have illustrated the preferred embodiment of the invention and wherein similar reference characters" designate corresponding parts throughout the several views: I

Figure 1 is a perspective View of our improved jack showing the sections of the body thereof in normal position,

Fig. 2 is a side elevation more particularly showing the mounting ;of the vpawls carried by the operating lever of the jack,

Fig. 3 is a transverse sectional view more particularly showing the construction of the body section of the jack,

Fig. 4 is a perspective view showing the body section of the jack detached, and

Fig. 5 is a side elevation showing-the'jack extended. i

In carrying out the invention, we employ a body section 10 which may be formed of any suitable material and which is provided, at its lower extremity, with a stir- Specification of Letters Patent.

of the section 10 is a substantially Patented May 29, 1917.

rup Formed in opposite sides of the section 10, are longitudinally"extending slots 12 and 13 each of which is substantially T- shaped in cross-section. The slot 12 opens through the lower end of the body 10 and slidably mounted in the said slot is an extensible section 14 which projects laterally from the adjacent side of thesection 10 and is provided in the outer edge thereof with a plurality of longitudinally spaced notches 15. The section 14, at its lower extremity, is formed with a foot 16, the under side of which is preferably concave so that the said foot will be adapted to firmly engage the ground or other surface. Slidably mounted in the slot 13 of the body section 10 is an extensible section 17 which laterally from the side of the section 10 opposite the section 14 and is provided in its outer edge with a plurality of longitudinally spaced notches 18. At thispoint, it will be'observed that the notches 18 are arranged in reverse relation to the notches 15 of the section 14. At its upper extremity, the section 17-is provided with astirrup 19 and at its lower extremity, the said section is formed with a laterally projecting stirrup 20, each of the said stirrups being adapt.- ed to engage a load as is also the stirrup 11 of the body section 10.

It will now be observed that the section 17 is adapted to rest against the stirrup 11 for supporting the said'section in normal position relative to the body section 10. Swingingly connected to the lower extremity U-shaped pawl 21 upon one extremity of which is formed a weighted arm or handle 22. The pawl 21 is adapted to engage in a notch 23 formed in the lower extremity of the sec tion 14 for supporting. the said section in normal position relative to the body 10 with the arm 22 arranged to normally urge the pawl to engage within the said notch. In this connection, it will be observed that when the jack is being collapsed, and the section 14 is moved to its normal position, the weighted arm 22 will act to automatically shift the pawl 21 to engage within the notch 23.

Pivotally connected to the body section 10, is an operating lever 24 which, at one extremity, is provided with a suitable socket to detachably receive a handle 25 and projects at its opposite extremity is bifurcated to formspaced arms 26 embracing the body of the jack and detachably connected thereto by a suitable pivot'bolt. Swingingly connected to the arms 26 to coact with the section 14 of the jack is a substantially U- shaped pawl 27 upon one extremity of which is formed a weighted arm or lever 28 nor mally urging the pawl to engage the teeth 15 of the said section. Swingingly connected to the arms 26 to coact with the section 17 is a substantially U-shaped pawl 29 identical with the pawl 27 and provided at one extremity with a weighted arm or lever 30 normally urging the pawl to engage the teeth 18 of the said section.

Swingingly connected to the upper extremity of the body section 10 is a substantially U-shaped pawl 31 which is similar to the pawl 21 and is arranged to coact with the section 17 of the jack. The pawl 31 is provided, at one extremity, with a laterally extending weighted arm or handle 32 normally urging the pawl to coact with the teeth 18 of the said section and it will be observed that the said pawl is adapted to engage the section 17 for holding the said section against downward shifting movement relative to the body section 10. In the normal position of the sections 14 and 17 relative to the body section 10, either the stirrup 19 of the section 17 or the stirrup 11 thereof may be engaged with the load, the jack being thus adapted to obtain a purchase upon the load at different heights and consequently reducing to a minimum the necessity for the initial adjustment of the jack. However, to accomplish, such adjustment, the section 17 may be manually moved upwardly upon the body section 10 to engage the load and when so moved, it will be noted that the pawls 29 and 31 will ride over the teeth 18 of the said section. When the section 17 is thus shifted upwardly upon the body section 10, the stirrup 20 will then be moved away from the stirrup 11 a suflicient distance to permit the said stirrup to be engaged with the load so that the jack may then be engaged with the load at any one of the threeelevations of the stirrups 11, 19, or 20.

In operation, the jack is first positioned to engage the load, in the manner previously described, and the pawl 21 is shifted from a position engaging within the notch 23 of the section 141- to a position coacting with the teeth 15 of the said section with the handle 22 normally urging the pawl to engage with the said teeth. The lever 24L is then rocked upon its pivot when the pawls 27 and 29 will coact with the teeth 15 and 18 of the extensible sections 1 1 and 17 to shift the body section 10 and the section 17 upwardly relative to the section 14 by a step by step movement. When the body section 10 and the section 17 are thus shifted upwardly, the pawls 21 and 31 will ride over the teeth of the said sections to be automatically urged by the weighted arms of the said pawls to engage with the said teeth for holding the several. sections of the jack at adjustment. In this way, the jack may be easily extended to lift the load and it will be observed that the pawls 27 and 29 will ride over the teeth of the sections 14.- and 17 to engage with the said teeth as the lever 24; is rocked upon its pivot. Preferably, the section it is longer than the section 17 so as to increase the effective height of the jack when extended and, of course, the length of the said section may be varied as desired.

Particular attention is now directed to the fact that when the jack is operated, as

just above described, the body section 10 will be shifted upwardly upon the section 14- at one rate of speed while the section 17 will be shifted upwardly upon the section 10 at a greater rate of speed, the sections 10 and 17 while being lifted, also being simultaneously moved relative to each other. However, by holding the pawl 29 in inactive position, the section 17 -will then remain stationary relative to the section 10 so that the said sections will then be lifted at the same rate of speed. Thus, when it is desired to lift the load quickly with a correspondingly increased leverage, the pawl 29 is shifted to coact with the section 17 while, when it is desired to lift the load more slowly, with a correspondingly decreased leverage, the pawl 29 is shifted to inactive position. Consequently, we provide an arrangement wherein the load may be lifted at difierent rates of speed and also wherein the leverage required to operate the jack may be correspondingly varied. For light loads, the sections 10 and 17 may be shifted relative to each other while being simultaneously shifted relat've to the section 14L while for heavy loads, the said sections may be lifted at the same rate of speed.

From the preceding description, it is thought that the manner in which the sections of the jack may be collapsed will be readily understood. The pawls 26 and 29 are manually operated to lower the sections 10 and 17 upon the section 14 by a step by step movement in a manner reverse to the operation of the said pawls in extending the jack and the pawls 21 and 31 are manually operated at the same time to properly cooperate with the teeth of the sections 1-1 and 17. It will therefore be seen that we provide a simple and efficient construction for the purpose set forth and particular attention is directed to the fact that the several pawls employed are so arranged as to permit the several sections of the jaclrto be manually shifted relative to each other to initially engage the load without the necessity of manually operating the said pawls, it being understood in this connection that the pawl 21 is first shifted to disengage from within the notch 23 of the section 14:. Moreover, the section 17 of the body of the jack is, at its lower extremity, so formed that this section may first be shifted to the limit of its upward movement to engage the load, as shown in Fig. 5, and the lever 24 then' operated to shift the section 10 upwardly upon the section 14 with thepawl 29 inactively riding over the lower end of the said section 17, so that the said sections, when in this position may be lifted at the same rate of speed without the necessity of manually holding the pawl 29 away from the teeth 18. I

Removably connected to the upper extremity of the section 17 to cooperate with the stirrup 19 thereof, is a load engaging member 33. This member will provide a firm bearing for the load tending to prevent the load from tilting sidewise.

Having thus described our invention, what we claim and desire to secure by Letters Patent is:

1. A device of the character described including a body section, extensible sections shiftably mounted thereon, a pivoted operating lever carried by the body section, and means connected to said lever at opposite sides of the pivotal center thereof and engaging with the said extensible sections with the said meansmovable in opposite directions upon the actuation of the lever to simultaneously shift the said extensible sections in opposite directions relative to the body section by a step by step movement.

2. A device of the character described including a body section, extensible sections shiftably mounted thereon, a pivoted operating lever carried by the body section, and means connected to said lever at opposite sides of the pivotal center thereof and normally urged in opposite directions inwardly toward the said extensible sections to engage therewith with the said means movable in opposite directions upon the actuation of the said lever for simultaneously shifting the said extensible sections in opposite directions relative to the body section by a step by step movement.

3. Avdevice of the character described including a body section, extensible sections adjustable in opposite directions thereon, a pivoted operating lever carried by the body section, means connected to said lever at opposite sides of the pivotal center thereof and engaging said extensible sections with the said means movable in opposite directions upon the actuation of the lever for shifting the said extensible sections in opposite directions relative to the body section,v

and means having weighted arms gravitating in opposite directions to urge the said last-mentioned means toward the said extensible sections to active position for holding the extensible sections at adjustment;

4:. A device of the character described in- Y engaging the extensible sections with the said means movable in opposite directions upon the actuation of the lever for shifting the said extensible sections relative to the body section by a step by step movement, and means cooperating with said first-mentioned means and engaging the said extensible sections for holding said extensible sections at adjustment with the said last-mentioned means shiftable for gravitating movement to inactive position for freeing the said extensible sections. a

5. A device of the character described including a body section, extensible sections shiftable in opposite directions thereon, means for holding one of said extensible sections fixed with respect to the body section, a pivoted operating lever carried by the body section, and means connected to said lever at opposite sides of the pivotal center thereof and engaging both of the said extensible sections with the said means movable in opposite directions upon the actuation of the lever for shifting the other of said extensible sections relative to the body section.

6. A device of the character described in cluding a body section, extensible sections adjustable in opposite directions thereon, substantially U-shapedpawls having the arms thereof pivotally connected to the body section with one arm of each pawl extended to provide a weighted lever, the said levers normally urging the bights of the said pawls to engage the said extensible sections for holding the extensible sections at adjustment, and means for shifting the said extensible sections relative to the body section.

7 A device of the character described including a body section, extensible sections shiftable upon the body section and provided with reversely arranged series of teeth, an operating lever pivoted to the body section, and means connected to said lever at opposite sides of the pivotal center thereof and shiftable in opposite directions upon the actuation of the lever to cooperate with said teeth for shifting the extensible sections by a step by step movement relative to the body section.

8. A device of the character described including a body section having slots formed in opposite sides thereof, extensible sections movable in opposite directions with respect to the body section within said slots, an operating lever pivoted to the body section,

paWls connected to said lever at opposite sides of the pivotal center thereof and normally engaging the said extensible sections With the said paWls movable in opposite directions upon the actuation of the lever for adjustably shifting the extensible sections in opposite directions relative to the body section, and pawls carried by the body section and engaging the said extensible sections for holding the extensible sections at adjustment.

9. A device of the character described including a body section, extensible sections mounted upon opposite sides of the body section and shiftable in opposite directions thereon, an operating lever pivotally connected to the body section, and Weighted paWls carried by the said lever upon opposite sides of the body section and normally urged to engage the said extensible sections for shifting the said sections in opposite directions relative to the body section upon the actuation of the said lever.

10. A device of the character described in cluding a body section, extensible sections shiftable in opposite directions thereon, an operating lever having arms pivotally connected to the body section, and paWls carried by the said arms at opposite sides of the pivotal center of said lever and simultaneously cooperating with the said extensible sections for shifting the said sections relative to the body section upon the actuation of the lever.

In testimony whereof We affix our signa- Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C.

Images