US829238A

US829238A - Lifting-jack.

Info

Publication number: US829238A
Application number: US30548106A
Authority: US
Inventors: Edwin E Thomas
Original assignee: Individual
Current assignee: Individual
Priority date: 1906-03-12
Filing date: 1906-03-12
Publication date: 1906-08-21
Anticipated expiration: 1923-08-21

Description

PATENTED AUG. 21, 1906.

E. B. moms. LIFTING JACK.

APPLIUATIOH FILED MAR. 12, 1908.

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PATENTED AUG. 21, 1906.

E. E. THOMAS.

LIFTING JACK.

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Al/T/YEJJEJ lb -WW EDWIN E. THOMAS, OF PORTLAND, OREGON.

LlFTlNG"JACK- Specification of Letters Patent.

Patented Aug. 21, 1906.

Application filed March 12, 1906. Serial No. 305,481-

To all whom it may concern:

, Portland, county of Multnomah, Oregon,

have invented certain new and useful Improvements in Lifting-Jacks, of which the ollowing is a specification.

Liftin -jacks as usually made must be placed c ose to the load to be raised, and oftentimes the lifting operation is attended with great danger to the life and limb of the operator, particularly when the load is high and composed of lumber or of loose material. It has been found also very di'llicult to get down low enough to use an ordinary 'ack when the load is close to the ground. hen the load is wide or on a platform, the jack is located under the middle of it with a suitable cross-bar; but it is a diil'icult and dangerous operation to place the jack in that position. Sometimes two jacks are used, one on each side of the load and connected with one another by a cross bar or beam. This, however, has been found to be a laborious and tedious method of lifting a load.

The object, therefore, of my invention is to provide a lifting-jack capable of use under various conditions and of very simple construction, having but few working parts and these being plainly exposed to view to facilitate their adjustment and permit convenient inspection and repair.

further ob'ect is to provide a lifting-jack which will one 1c the operator to stand at a safe distance from the load during the operation of raising it.

A further object is to rovide a jack which can be easily and quicliily lowered without danger of injuring the attendant.

Other obi'ects of the invention will appear from the fo lowing detailed description.

The invention consists, generally, in a base or bar normally stationar and a movable bar havin pivotal connections with the base and held in parallel relation therewith, said movable bar engaging the bottom of the load to be raised.

Further, the invention consists in providing the movable bar with a hook or step device whereby the preliminary raising of a low-down load may be effected.

Further, the invention consists in various constructions and combinations, all as hereinafter described, and particularly pointed out in the claims.

In the accompanying drawings, forming part of this specification, Figure I is a side elevation of a liftin '-jack embodying my invention, the movab 0 her being shown in its down position. Fig. 2 is a similar view illustrating the jack in its raised )osition. Fig. 3 is a top view of the ark. view on the line a: a: of Fig. 2. Fig. 5 is a sectional view on the line 2 2 of Fig. 2. Fig. 6 is a sectional view on the line y 1 of Fig. 2. Fig. 7 is a detail view of the mechanism for operating the jack.

In the drawings, 2 represents a base rail or bar having forward and rear trucks 3 and 4 pivoted thereon on each side of the bar. These trucks or wheels are of any suitable size and facilitate the movement of the jack from place to place. shoes may be provided, or the rail may be allowed to restdirectly upon and slide on the ground.

5 is a bar arranged above the bar 2.

6 is a lever pivoted at its upper end to the bar 5 near one end and havingan antifriction-roller 7 at its lower end, which rolls on the edge of the bar 2, the lever 6 being composed, irefcrably, of two parts or pieces, the ends 0 which lap the upper edge of the bar 2 and form guides for the wheel or roller thereon. A second lever 8 is pivoted at its lower end to the bar 2 beneath the pivot of the other lever on the bar 5, and the up er end of the lever 8 has an antifrietion roller or wheel 9, which engages the lower edge of the bar 5, being guided thereon by the projecting forked end of the lever 8. The levers 6 and 8 are connected with one another centrally by a ivot-pin 10. The bars 2 and 5 are thus hcl in parallel relation with one another during the upward and downward movement of the jack. The end of the bar 5 is provided with a pivoted hook or step 11, which extends down below the level of the base-rail of the jack and is ada uted to he slipped in under a timber or ice which lies near the ground to enable the operator to impart a preliminary raising movement to the load preparato to slipping the bar 5 beneath the same the load of course being blocked up to allow the jack to be lowered and the bar 5 inserted beneath the load. In some instances the movement of the hook may be suflicient to raise the load to the desired height without utilizing the bar. The

Fig. 4 is a sectional In place of the trucks lever to be dropped and the dog 18 to engage hook, however, is intended as an ad'unct to the bar and may be used in connection with it or not, as preferred. Its attachment to the jack gives it a wider range of use than usually found in appliances of this kind.

On the rear end of the base-rail 2 a bar 12 is pivoted, having a series of ratchet-teeth 13, said bar projecting at its upper end through a slot 14, provided in a head-block 15 on the bar 5, the ratchet-bar serving as a guide for the head-block in its vertical movement with the bar 5. An operating-lever 16 is pivoted at 17 on the block 15 and carries a gravity-dog -18, pivoted at 19 thereon and havi a weighted handle 20, which normallg holds the dog in engagement with the ratchet-teeth 13. A ravity-do 21 is pivoted on the bar 5 and has a weig ted handle 22, which holds the said dog in enga ement with the ratchet-teeth 13. Both 0% these dogs are ads ted to slip over the ratchetteeth when the bar 5 is raised and lock the said bar a ainst downward movement. The lever 16 when raised on its pivot will move the dog 18 over one or more ratchetteeth, according to the degree of movement of the lever, and then when pressure is applied to. the outer end of the lever to force it down the bar 5, whereon the short arm of the lever is mounted, will be lifted to raise the load. During the time the lever 16is being swung upward the dog 21 will remain in engagement with the ratchet-teeth and lock the bar 5 against depression. In other words, the dog 18 will aetas a fulcrum for the lever 16 during the raising of the bar 5, while the dog 21 will serve as a lock and relieve the lever 16 of the weight of the load and allow it to be oscillated easily to impart the upward ste -by-ste movement to the lifting-bar 5. he loa ma be anywhere along the horizontal top of t e bar 5. The levers 6 and 8 will evenly distribute the strain, and it will be immaterial whether the load be upon the end of the lifti -bar or the middle ortion thereof. The loc in -dog 21 will sli e over the ratchet-teeth as t e bar 5 is raised tooth by tooth, and there will be no danger of the load falling through accidental movement of the operating-lever.

When it is desired to lower the load, the operator will grasp the lever 16 with one hand and raise the weighted handle 20 with the other hand, thus disengaging the dog from the ratchet-teeth. This will allow the a lower tooth on the rack-bar. Then ear down on the lever Ifiuntil the load has been raised slightly and raise the handle 22, dieenga the dog2l from the ratchet. Then b sa ing the weight of the load to swing t e lever 16 upward the dog 21 may be lowered one or two teeth, as desired. By reeatin the above-described 0 eration the ack with the load thereon can e easily and quickly lowered to the desired level. .If for any reason it is desired to drop the jack instantly to its lowest position, the lever 16 is raised to a point above the up er limit of its .normal stroke or until a beve ed surface 23 on the said lever engages a pin24 on the block 15. When this occurs, the dog 18 will be automatically disengaged from the ratchet teeth, and u on lifting the handle 22 the do 21 will also he disengaged and the jack wil drop by gravity to its de ressed position. When it is desired to raise the jack to its elevated position without any load thereon, the

of the bar 5 shown in Fig. 1 and then when the timber is blocked the hook may be removed and the entire jack thrust under the timber, as also indicated in said figure, the dotted lines representin a stick of timber when first engaged by the lifting-hook, and then the same stick of timber raised to a sufficient level to allow the bar 5 to be thrust beneath it. I regard this lifting-hook as a useful adjunct to my invention, but not an indispensable one, as the jack will be thorough y practicable and a valuable device for handlin r lumber and other material, even if the hool; is entirely omitted. I do not wish to be confined either to the use of the wheels or trucks in connection with this jack, as they may be omitted, if desired. In various ways also the details of the o crating mechanism may be modified wit out departing from my invention.

I claim as my invention 1. The combination with a base-bar, of a lifting-bar, means connectin said base-bar and said liftin -bar, means or raising and lowering said ifting-bar, and comprismg a ratchet-bar and lever and dogs carried by said lifting-bar and lever and means carried by said liftin -bar and adapted to enga e the bottom of a cad below the level of sai ing-bar when in its depressed position, substantially as described.

2. The combination with a base-bar, of a vertically movable lifting bar supported thereon, said lifting-bar being horizontal and moving vertically'in parallel relation with said base-bar, and a ratchet-and-lever mechanism for raisin and lowering said liftingbar and means or trippin said mechanism 0 allow the quick depress on of said lifting- 3. The combination with a base-bar havmg carrying-wheels, of a lifting-bar, means connecting said base-bar with said lifting-bar lift- .ing pivoted at one end to one of said bars and havin an antii'riction-roller at the other end at apted to travel on the edge of the other bar, and a ratcl1et-and-lever mechanism for raising and lowering said lifting-bar.

5. The combination with a base-bar, of a vertically-moving lifting-bar supported thereon, a ratchet-bar mounted on said base-bar, a dog provided on said lifting-bar and engaging the teeth of said ratchet, an operating-lever pivoted on said lifting-bar, and a dog carried by said operating-lever and also engaging the teeth of said ratchet, and said dogs normally locking said lifting-bar against depression, substantially as described.

6. The combination with a base-bar, of a vertically-moving liftingbar supported thereon, a ratchet-bar pivoted on said base-bar and whereon said lifting-bar is vertically slidable, an operating-lever pivoted on said lifting-bar, a do carried by said operatinglever and engaging said ratchet-teeth, said dog having a beveled surface adapted to engage a fixed pin provided on said lifting-bar when said lever is raised beyond the normal limit of its upward movement, and a lockingdog carried by said lifting-bar and engaging the teeth of said ratchet, substantially as described 7. The combination, with a base-bar, of a vertically movable liftin bar supported thereon, said li Fling-bar being horizontal and moving vertically in parallel relations with said base-bar and a ratchet-and-lever mech anism having lifting and locking do s and means for tripping said. lifting-dog, w ereby upon disengagingosaid locking-dog with one hand and raising said lever with the other, said lifting-bar can be easily and quickly lowered, substantially as described.

8. The combination, with a basebar, of a vertieally-mrwii1g lifting-bar supported thereon, a ratelwt-bar pivoted on said base-bar and whereon said lifting-bar is vertically slidable, an operating-lever pivoted on said lifting-bar, a dog carried by said operatinglever and engaging said ratchet-teeth, a lockingalog carried by said lifting-bar and also engaging the teeth of said ratchet, and means for automatically tripping said leverdog when said lever is near the limit of its upward movement whereby upon raising said lever slightly and tripping said locking-dog, said lifting-bar can be easily and quickly lowered, substantially as described.

In witness whereof I have hereunto set my hand this 20th day of February, 1906.

EDWIN E. THOMAS.

Witnesses F. G. DAVIS, ELIJAII Connmr.