US2311063A - Shore jack - Google Patents

Description

SHOREV JACK Fgled May 19,4 1942 'Lul' l INV ENT OR.

Patented Feb. 16, 1943 UNITEDA STATES K PATENT VOFFICE SHORE JACK n Hubert L. Martin, Cincinnati, Ohio Application May 19, 1942, serial No. 443,597

3 Claims.

The present invention relates to improvements in mechanical jacks and is particularly directed to raising devices for adjusting load-sustaining, vertical members such as shores used in building construction Work, or the like.

In the construction of forms for supporting poured concrete above the building level, such as in forms for making oors for the second story of said building, it is the practice to use a standard length wooden shore which rests on a mud sill at building level and extends vertically upward to support at its upper end a fabricated form for holding poured concrete until it is set. A requisite to the use of standard length shore members, therefore, is that all the mud sills be brought to a common level. This operation must be supervised by skilled men and requires considerable time for its completion. An alternative method of constructing concrete forms is to bring all the mud sills to an approximate level and then out the shore members to flt each particular sill. This method is wasteful of shore material and also requires considerable time of skilled laborers for its accomplishment.

It is .an object of this invention to provide a jack which permits the use of a standard length shore without bringing the supporting mud sills therefor to a common level. 'I'his is accomplished by mechanically raising a shore to its proper operative position and then inserting a proper wedge thereunder` betweenthe bottom of said shore and the sill.

It is another object of the invention to provide an improved jack for shore members which is particularly adapted to facilitate the vertical adjustment of said member.

Another object of the invention is to provide an improved grappling or clamping member which is economical to construct, is eilcient in operation and which is particularly adapted for use in connection with a shore jack of the general type hereinbefore described.

Other objects of the invention will be apparent from the following specification and drawing, in which:

Fig. 1 is a side elevational view of my jack shown in operative position, parts thereof being shown in fragmental cross-section.

Fig. 2 is an enlarged cross-sectional view taken on line 2 2 of Fig. 1.

Fig. 3 is an enlarged cross-sectional view taken on line 3 3 of Fig. 1. i

Fig. 4 is an enlarged cross-sectional view taken on line 4-'4 of Fig. 2. y

'Ihe jack 6 is illustrated in Fig. 1 in connection with a vertical shore member I which is resting upon a mud sill 8 and supporting, at its upper end, a concrete form 9. The jack consists of a base I0 having a ilat platform I I resting upon the ground level I2, said platform being connected by screws I3 to a centrally disposed upright I4. The upright has a pair of spaced plates I5 fastened to opposed sides thereof by bolts I6, said plates supporting between them at their upper ends a fulcrum pin I'I. Braces I8 are connected to the end po-rtions of the pin I'I and are fastened at their lower ends to the platform by bolts I9.

A lever 20 is rotatably mounted on the fulcrum pin I1, and is provided at its short working end with an eye 2| which is preferably formed thereon by means of a strap 22 which has said eye formed centrally thereof. The ends of said strap are fastened to opposed edges of the lever by means of bolts 23.

A clamping or grappling device is rotatably mounted in the eye 2| and consists of an S-shaped member 24 (Fig. 2) which is formed from a straight piece of round stock. The member so formed has three transversely disposed, spaced, parallel straight portions 25, 26 and 21, adjacent straight portions being connected by longitudinal straight portions 28 which are alternately disposed on opposite sides of said transverse portions -and at right angles thereto. As shown in Fig. 2, all of said straight portions are joined along their adjacent ends by smooth curves.

A transverse opening 29 is formed between the transverse portions 25 and 26 for receiving opposed sides of the shore 'I and, as shown in Fig. 4, said portions are spaced so as to allow suflicient clearance between them for easy insertion of the shore member therebetween. The straight portion 21 is rotatably held in the eye 2| and a bar, indicated by dotted lines 30, may be welded between the end of the portion 21 and the longitudinal straight portion 28 to prevent removal of said clamping device from the jack.

vIn operation, when a shore 'I is to lifted to its operative position and wedges 3l inserted between it and the -mud sill, the jack 6 is positioned relative thereto, as indicated in Fig. 1. The clamping .device is Imoved transversely into en gagement with said shore and will be maintained in a substantially horizontal position. By exerting a downward force on the free end of the lever, the nose end thereof will rise and raise the adjacent end of the clamping device, thus providing a twist to said device which clamps the shore firmly between the parallel portions 25 and 26. This operative position is shown in dotted lines adjacent transverse portions forming clamping` jaws for transverse insertion around a member to be raised while said remaining portion formsa pivot connection for the device with said lever.

2. A shore jack comprising a base, a lever mounted on the base and having a horizontal, transverse eye formed at the working end thereof, and an S-shaped clamping device having three transverse straight portions, and longitudinal straight portions joining adjacent transverse portions on opposite sides of the device, two of said transverse portions lforming clamping jaws for transverse insertion of a shore, while the remaining transverse portion is rotatably held in the eye.

3. In a device of the character `described a base, a lever on the base and an S-shaped clamping member formed from a straight piece of round stockv and having three` spaced, parallel straight portions disposed transversely of said lever, longitudinal straight portions joining adjacent transverse portions on opposite sides of the device, two adjacent transverse portions forming clamping jaws for transverse insertion around a member to vloe raised while said remaining portion forms a pivot connection for the device with saidllever.

HUBERT L. MARTIN.

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