US2796299A

US2796299A - Extension scaffold jack

Info

Publication number: US2796299A
Application number: US388205A
Authority: US
Inventors: George D Freeman
Original assignee: Individual
Current assignee: Individual
Priority date: 1953-10-26
Filing date: 1953-10-26
Publication date: 1957-06-18
Anticipated expiration: 1974-06-18

Description

June 18, 1957 Filed Oct. 26, 1953 Fig.

G. D. FREEMAN,

EXTENSION scAFFoLD JACK 2 Sheets-Sheet 1 George D.. Freeman INVENTOR.

June 18, 1957 G. D. FREEMAN EXTENSION soAFFoLD JACK 2 Sheets-Sheet iled Oct. 26. 1953 George D. Freeman INVENTOR WM my;

United States Patent O 2,796,299 EXTENSIoN scAFFo'LD JACK George D. Freeman, Alvin, Ill. Application October 26,1953, Serial No. 388,205

1 Claim. '(Cl. 3044-29) This invention relates to 'an extension scaffold jack and more specifically provides 'a 'scaffold to be employed in construction work wherein 'the Yscaffold may be vertically adjustame without removing 'the scaffold boards and the various materials usually disposed'th'ere'o'n.

Anl object of this 'invention istq'provide van extension 'scaffold .jack having a plurality 'of suecess'ively extendable frame members which are telescopic in relation to each other and including means for extending the frame, locking the frames in Yextended position and bracing the 'frames in their extended position.

A 'furtherebjeet Aof this invention is .to provide a `neveu rack and pinion lifting means wherein the rack is sectional wherein successive'se'ctions 'ofjth'e rack may be attached to the first section of the vrack thereby extending successive frame members. Y

A further VVob'jerc't yof this invention is to ,provide an Aextension scaffold jack having a-d e tachable se'ction secured thereon and a plurality `of extensible frames with each of lt-he 'frames having alignabl'e apertures therein 'and a rlocking pin extending therethrough "for :securing the 'frames in e'X- tended position.

Yet another object of this invention is to `provide an extension scaffold jack which is simple in construction, sturdy and rugged in nature, efficient to operate and constructed of 'readily 'obtainable materials thereby lending itself to economicrnanufacture.

These together with` other objects Aand -advant'ageswhich will become subsequently apparent reside in ithe A'details fof construction and operation as more :fully hereinafter described fand claimed, reference being had to fthe `accompanying drawings forming a part hereof, wherein "like numerals refer to like parts throughout, and in which:

Figure -1 is a `side View of 4the extension scaiiold jack -of the finven't'ion Ain Yextended Aposition "with the uppermost member being a detachable extension;

Figure 2 is Va longitudinal, vertical section 'taken substantially 'along the `center -line of the 'frame showing the details-of theirack-and pinioneextension means;

Figure 3 -is'a transverse, vtop plan section taken substa`ntiallly along section line 3&3 of YFigure `1 s'howi'ngthe'rela- 'tionship of 'the rack andpi-nion |lifting means;

Figure l Iis fa side elevational `vi'ewo'f the extensionscaffold jack in collapsed position with the top extension removed therefrom;

Figure 5 is a detail perspective View showing one of the detachable sections of the rack;

Figure 6 is a detail top plan section taken substantially along section line 6-6 of Figure 4 showing details of the brace attaching means; and

Figure 7 is a detail section showing the projecting guide and the socket receiving portion of the uppermost extension which is detachable from the uppermost frame.

Referring now specifically to the drawings in generell, it will be seen that the numeral 10 generally designates the extension scaffold jack of this invention generally comprising a lower frame member 12, a second framel member ICC 2 14, a third or upper frame member 16 and a detachable exten-sion frame member 18.

It 'will be seen that each ofthe '

frame members

12, 14, 1'6, and 18 is formed with a pair of vertical uprights and a pair of

cross-braces

20 and 22 being connected to opposite end 'portions of the uprights of the frames by suitable screw threaded members 2'4 having an operating handle 26 thereon for ease of manipulation. The

cross braces

20 and 22 are secured at point 28 where the braces cross over each other. Each of the uprights of the

frame members

12, 14, 16 and 18 is tubular with the ilowermost frame 12 having a base member 30 secured to the lower Vend of the v tubular uprights forming a support and closure for the lower end of the uprights ofthe frame member 12.

As shown in Figure l, the frame 16 includes a crossmember 32 connecting the upper ends of the vertical uprights of 'the frame members 16 'and forming a support for scaffold boards or lthe like. As shown in Figure 7, the upper ends of the 'vertical uprights of the frame 16 are each provided with an upwardly `extending rod 34 with an enlarged ball vmember 36 on the end thereof 'and it will be seen that the ball member 36 forms a guide and positioning means for the 'tubular uprights of the extension member 18 wherein the extension member or frame 18 'may 'be removed from the upper frame member 16. A cross member is secured between the upper ends of the vertical uprights of the extension frame 18 with the vertical uprights extending slightly beyond the cross-member wherein scaffold boards will be retained on the cross- *member 38 inan obviousmanner.

A's will be seen in V'the drawings, the upper end of the vertical uprights of the lower frame member 1-2 andthe intermediate frame member 14 and the lower ends of the upper'frame member 16 andthe intermediate frame member 14 are provided'with apertures 40 which are alignable with each other when in --their extended position and lock- -ing pins 42 are provided for Vinsertion in the aligned apertures when the frames `16, 14 and 12 'are in extended position, thereby locking 'the frames in such extended position. :lt will ibe understood that the brace members 20 and-22 `on the frame 'member 14'may be removed, thereby lpermitting the uprights `of the frame 14 to be telescoped into the uprights of 'the frame 12 as the uprights of the frame :14 are 'smaller than the uprights of the frame 12, vand it will 'be further `understood that the uprights of the 'frame member 16 may Vbe telescoped .into the uprights of the frame member "14 after removal yof the brace Vmembers 20fand 22. The extension frame 18 may be removed and the vdevice will be in its collapsed position, as shown in vFigure-4.

It will be seen yin the drawings that a projecting lug member 44 Ais rigidly ysecured to the side of one of the vertical uprights of the upper frame member 16, and a depending elongated .member 46 is rigidly secured to the undersurface thereof and extends downwardly parallel to Vthe vertical upright of the frame 16 in spaced relation thereto. .It will be Lseen that vthe elongated member is provided with projecting teeth 48 along one side thereof and an aperture 50 is provided at its lower end for a purpose described hereinafter. It will be understood that the elongated member i6 with the teeth 48 thereon forms a rack.

A U-Shaped bracket member 52 is secured adjacent the upper `en-dof the vertical upright of the lower frame member 12 by suitable welding lor the like and surrounding the elongated member 46. A spacer member S4 is secured to the outer circumference of the vertical upright of the frame 12 and includes `a bearing portion 56 riding against the rear edge of the elongated member 46. A pinion gear 58 is journaled between the legs of the U- shaped member 52 `on a suitable axle 60 with one end of the axle 60 projecting beyond the U-shaped member 3 52 and a handle 62 is secured to the projecting end of the axle 60. The pinion gear 58 includes teeth 64 which are in meshing engament with the teeth 48 on the elongated rack 46. A gravity operated p-awl 66 is pivotally secured to the inner side of one of the legs of the U- shaped member 52 adjacent the upper edge thereof and engaging the teeth 64 of the pinion gear 58 wherein the gear 58 may be rotated only upon disengagement of the pawl 66 from the teeth 54. It will be seen that the bearing surface S6 maintains the elongated rack 46 in correct position for meshing of the

gears

48 and 64. As 4shown in Figure 1, a second section of rack, indicated by the numeral 68, may be secured to the rack member 46 by insertion of a suitable fastener 70 through the aperture S in the rack 46 and an aperture 72 in a projecting lug on the upper end of the section 68. The

ra-ck section 68 is provided with an aperture at the bottom end thereof for securing successive sections of elongated racks wherein each section is similar to the section 68, as shown in Figure 5, with each section having teeth 48 thereon. It will be understood that the successive frame members 16, @14 and the like may be extended -by `attaching successive sections of the rack to the lower end of the first rack Section 46 wherein the device has a long range of adjustability.

The operation of the device will be readily understood. The extension scaffold jack 10 of this invention is in its normally collapsed position in Figure 4, and by releasing 1 members 24. It will be seen that the ycross-piece 32 may i be used to support a scaffold board thereon. It will be understood that additional sections 68 may be attached to the original rack section 46 for extending the

frames

16 and 14 to their uppermost vertical positions in an obvious manner. If a greater vertical height is required, the

extension frame 18 may be positioned over the upper frame 16 with the tubular uprights of the extension 18 extending over the guide bar 36 and the extending shank 34 wherein the uprights of the frame 18 are in alignment with the frame 16 and supported thereon. The

vcross-member 38, like the cross-member 32, is adapted to hold a scaiold board thereon and it will be noted that both of the cross-members 32 and 38 are recessed below the upper ends of the vertical uprights of the

frame members

16 and 18 wherein scaffold boards will be retained on the cross-members. Obviously, the device of this invention may `be constructed of readily obtainable pipe or other tubular members wherein the device will be economically feasible and the device may be utilized without removing the scaffold boards and vertically adjustable without removing the scaffold boards and the usual material found thereon. This is especially useful in masonry construction where there is usually a heavy load of building blocks, mortar or tools on the scaffold boards and it is desirable to adjust the scaffold boards vertically without removing the material on 'the boards. The locking pins 4-2 provide .a locking means for securing the frames in fully extended position and the pawl member 66 provides a lock for securing the frames in any extended relation.

From the foregoing, the construction and operation of the device will be readily understood 1and further explana-tion is believed to be unnecessary. However, since numerous modifications and changes will readily occur to those skilled in the art, i't is not desired to limit the linvention to the exact yconstructionsh'own and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the appended claim.

What is claimed as new is as follows:

An extension scalold jack comprising a pair of tubular verticaluprights, brace means interconnecting said uprights, a plurality -of tubular extensible members telescopically received in each of said tubular uprights, a cross member rigidly connecting the upper ends of the upper pair of tubular extensible members, .an extensible rack member connected at one end to one of said uppermost pair of tubular extensible members and extending downwardly in spaced, parallel relationship thereto, a bracket extending from one of said tubular vertical uprights, guide means in said bracket for said rack member, a gear journaled in said bracket and having teeth in meshing engagement with the teeth of said rack member, a handle attached to said gear for moving the rack and tubular extensible members upwardly with respect to the tubular vertical uprights, said extensible rack member beingl provided with a plurality of detachable rack portions each suspended from a higher rack portion, each portion having a length substantially equal to the length of a single tubular extensible member, and removable 'lock pins in said tubular vertical uprights and lthe lowermost tubular extensible members for locking said tubular extensible members in upwardly moved position.

References Cited in the tile of this patent UNITED STATES PATENTS 60,085 Tanner Nov. 27, 1866 382,245 Stadler 4May 1, 1888 417,678 MacLaurin Dec. 17, 1889 831,994 Rudman Sept. 25, 1906 1,012,246 Clarke et al. Dec. 19, 1911 1,084,966 Rodes Jan. 20, 1914 1,442,075 Knechtel Ian. 16, 1923 v 1,725,329 Blandford Aug. 20, 1929 1,905,626 Hershey Apr. 25, 1933 2,062,473 Norton Dec. 1, 1936 2,290,450 Renschin July 21, 1942 2,311,988 Lavn Feb. 23, 1943 2,472,887 Core June 14, 1949 2,546,674 North Mar. 27, 1951 2,573,575 Keroson Oct. 30, 1951 2,672,319 Nelson Mar. 16, 1954