US1320478A - Harry alqhzq king - Google Patents

Description

H. A. KING.

LIFTING JACK.

APPLICATION man OCT- 19, I916.

Patented Nov. 4, 1919.

WITNESSES ATTORNEY HARRY ALONZO KING, QEAST'ORIA, OREGON. v I

LIETING-JAGK.

Application filed October 19, 1916.

To all whom it may concern:

Be it known that I, HARRY ALoNzo KING, a citizen of the United States, residing at Astoria, in the county of Clatsop and State of Oregon, have invented certain new and useful Improvements in Lifting-Jacks, of which the following is a specification.

My invention relates to a lifting ack of the screw type.

The main object of the invention is to provide an exceedingly simple construction of jack without impairing efficiencyand durability, so as to reduce the cost of manufacture to a very low figure. Particularly it is a desideratum to provide the screw with ratchet means to cooperate with a pawl mounted by a supporting plate turnable about the screw and normally held against descent by engagement of the pawl with the ratchet means.

Other advantages and specific objects will become apparent as the following description progresses with reference to accompanying drawings illustrating one preferred embodiment and wherein Figure 1 is a view showing my improved jack in side elevation;

Fig. 2 is a cross sectional view on the line 22 of Fig. 1, and,

Fig. 3 is a cross sectional view on the line 33 of Fig. 1.

Fig. 4c is a view of the lifting screw showing the ratchet teeth and operating pawl.

Referring specifically to the drawings, wherein like reference characters designate like or similar parts, 4 designates any improved type of support for a lifting screw 5 which may be provided with a cap 6 turnable independently thereof if preferred. Lifting screw 5 passes through an opening in the crown plate 7 of the stand 1 and in the said opening screw-threads cooperate with the screw-threads of the lifting screw. The lifting screw may thus be extended or dis tended relatively to the crown plate 7.

A supporting plate 8 is provided having a supporting lug 9 through which a rivet 10 or other suitable pivot passes, and which mounts a pawl 11. Plate 8 also has a ring 12 extending from the lug 9. The ring 12 does not tightly bind the lifting screw memher 5 but is freely rotatable around the same at its peripheral wall above the screwthreads. The lifting screw member 5 is also cut away in order to provide equi-distant Specification of Letters Patent.

PatentedNov. 4, 1919.

Serial No. 126,575.

longitudinallyextending teeth 15 with intermediate slots 16 to thereby form a ratchet device. A lever 11 has a pawl at 17 through which the pivot 10'specifically passes, and this pawl has points 18 and 19, respectively disposed on opposite sides of the pivot 10. It will be noted that the pawl 17 normally has one of its points disposed in one of the grooves 16 and thus as a result, the pawl rests upon the base of such groove and prevents downward movement of the support 8 thus preventing displacement of the lever and its support.

In use, stand 4, lifting screw device 5 and the support 8 with the lever 11 mounted thereon are disassembled. To assemble them the lever 11 is brought into radial relation with the axis of the lifting screw device 5 and such screw device is then inserted through the ring 12 until the slots 16 are.

reached, whereupon the lever 11 is moved on its fulcrum so as to extend into one of the slots 16 and thus be supported against descent by the base wall of the slot. The screw device may then be screwed into the crown plate 7.

In order to actuate the jack, the cap 6 is brought into proper relation with the work or article to be lifted whereupon lever 11 is pulled in one direction with say point 18 extending into one of the slots 16 and bearing against one of the teeth or ribs 15, thus turning the jack 5 and moving the screw relatively to the crown plate 7 and the work. After the turning action, lever 11 is moved in the reverse direction until the lever 11 is in radial relation to the axis of the screw 5. It is then held in such position and moved as far as desired in the reversed direction. It is then again tilted so as to move the point 18 into one of the slots 16 whereupon it is again turned in the initial direction so as to turn the screw 5. These operations are repeated and thus the lever functions as a pawl and the screw functions as a ratchet. If desired, the lever 11 may be tilted so that the point 19 will extend into one of the longitudinal axis of the lifting member, a

supporting means turnable about said member, turning means on said supporting means extending into said slot and resting on said wall to mount the supporting means against displacement by movement in one direction.

2. A lifting jack having a liftingmember, a supporting means slidable along said member for attachment to said member, a pawl on said supporting means, said pawl being movable to position in radial relation with the axis of the lifting member, and said pawl being movable from said position to overlap the lifting memberand thereby prevent displaeement of the supporting means from the lifting member through movement in onedirection.

V 3. A lifting jack having a lifting member, a supporting means having a supporting lug anda ring, said lifting member being insertible through said ring whereby said ring may be mounted turnably relative to the lifting'member, said lifting member having a plurality of slots and ribs to form a ratchet, a lever having a pawl pivoted to said lug, and said pawl having portions on olpposite sides of its pivot to extend into said s ots.

4. A lifting jack having a lifting member, a supporting means having a supporting lug and a ring, said lifting member be ing insertible' through said ring whereby said ring may be mounted turnably relative to the lifting member, said lifting member having a plurality of slots and ribs to form a ratohet a base wallbetween said ribs being at a right angle to the longi-V tudinal axis of the lifting member, a lever having a pawl pivoted to said lug and said pawl having portions on oppositesides of its pivot to extend into said slot and rest on said base wall.

In testimony whereof I afiix my signature in presence of two witnesses. HARRY ALONZO KING. WVitnesses:

- P. W. PETERSON, V GUY O. LAITIN,

copies of this patent may be obtained for five cents each, by addressing the Commissioner of latelits,

' Washington, D. Q. l

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