US2936989A - Ladder jack - Google Patents

Description

May 17, 1960 c. slEK 2,936,989

LADDER JACK Filed Nov. 20, 1958 3 Sheets-Sheet 1 May 17, 1960 Filed Nov. 20, 1958 @29.7. l so l m/f/Q (4 i? @M/gi@ C. SIEK LADDER JACK May 17, 1960 3 Sheets-Shea?I 3 Filed Nov. 20, 1958 @Me/ee@ 76- ,duwen bor: Clarence ,5 1 e k United. States LADDER-JACK i y Clarence Siek, Des Moines, Iowa' g lApplication November 20, 1958, Serial No. 775,277

9 Claims. (ci. 24a-23s) My invention relates to scatloldingequipment and more particularly to scaffolding equipment used in conjunction with ladders. Y

`Many devices have been used in combination with ladders to create a scaffolding unit. These devices known to me are generally of very heavy construction. Furthermore, these ladder jacks are very awkward to put to u'se land are generally unsafe unless very carefully operated.

"Therefore, the principal object of my invention is to provide a ladder jack of light weight'which is easy to -handle and to operate. A further object of my invention is to provide atladder jack that will be safe to use. s

A still further object of my invention 'is ladder jack that can be usedon Veither side of the ladder units. f A still further object of my invention is to provide ai ladder jack that has its elements adjustable to compensate for diierences in the angle ofthe ladder units. v

A still further object of my invention is to provide av ladder jack that is economical of manufacture,mdurable in use and reiined in appearance. l

These and other objects will .be apparent to those' skilled in the art. V

My invention consists in the construction, arrangements, and combination, of the various parts of `the device, whereby the objects contemplated are attained as'hereinafter more fully set forth, specifically pointed out in my claims, and illustrated in the accompanying drawings, in which:

Fig. 1 is a perspective view ofrvmy device in one of its operating positions;

Fig. 2 s an elevational view Aof my device in a second operating position;

Fig. 3 is ya partial plan view of my device; Fig. 4 is a sectional view ofl myldevice taken online 4--4 ofFig. 3;-

Fig. 5 is a partial perspectiveview badi-ment of my device;

Fig. 6 is a side elevational view of the structure shown in Fig. 5; l

Fig. 7 isa View similar to that of Fig. 6 but illustrating the function of my bracket element;

Fig. 8 is a perspective view of my bracket element;

Fig. 9 is a partial perspective view of a further embodiment of my device;

Y Fig. 10 is a sectional view taken in a plane transverse to the longitudinal axis of my bar element; and

Fig. 11 is a sectional view of my device taken on line 11-11 of Fig. 10. I l

I have used the numeral 10 to designate a hollow elongated bar which can be rectangular in cross section and is preferably made of aluminum or the like. Bar 10 can have a plurality of parallel, vertical holes 12` towards one of its ends which extend through the bar. A pin 14 secured to bar 10 in the near 4vproximity ofholes'12'by of a preferred emto provide-a inserted into the holes.

.and 7.

Bar 10A has kan elongated slit 40 in the lower portion of its two opposite sides which-extends in a horizontalv Z The length of pinr14 is sucient to extend some distance through and beyond the bar.

A slot opening 18 appears in the top center portion of bar 10 and a horizontal pin 20 extends transversely across the inside of the bar directly underneath slot 18.

A second slot opening 22 appears in the top of bar 10 near the end opposite to holes 12. A pin 24 is disposed below slot 22 in the same manner that pin 20 appeared below slot 18. A sleeve 26 is rotatably mounted on pin 24 and extends the full length thereof. A'iexible cable 28 has one of its ends secured to pin 20 and then extends upwardly out of slot 18, downwardly into slot 22, thence underneath sleeve 26 and upwardly out of slot 22. The free end of cable 28 is secured to chain 30 which is comprised of a plurality of links 32. A Y-shaped hook member 34 has a hook element 36 on its lower end and hook elements 38 on its upper ends.

InFgs. 5, 6 and 7, I have shown the preferred form of my bar member. In these figures I have shown a bar member 10A which serves the same general purpose as bar 10. Only the distinguishing details of bar 10A as compared to bar 10 have been shown in Figs. 5, 6

direction parallel to the bottom of the bar. A plurality of spaced apart lugs 41 is mounted on the top of bar 10A along the centerline thereof. The sides of the lugs nearest the end 42 of bar 10A are tapered upwardly and outwardly. A bracket element 44 has a crossbarv 46 which is slidably mounted in slits 40. Cross bar 46 dwells in ya plane perpendicular tothe longitudinal axis of baiy 10A. The length of cross bar 46 is substantially the same as the width of bar 10A and the cross bar gisv capable of being rotated aboutgits longitudinal axis in` slits 40. Bracket element 44 is further comprised of a rod 45 which has a hook portion 48 on its lower ends and which extends vertically upward from its end portions toa horizontal U-shaped hoopV portion 50. The

open part of hoop portion 50 and hook portions 48 face-v n opposite directionsand the hook portions open towards the end 42 of bar 10A when `the bracket element y44 is mounted on `the bar 10A. Horizontal cross barV 46 is secured to rod 45 at points just above hookpori" tions 48 so that the hook portions will extend slightly below the bottom of bar 10A. The vertical distance bef tween cross bar 46 and the plane of hoop portion 5,0

is substantially equal to the vertical distance from the top of bar 10A to slits 40. v

I have used the numeral 52 to designate'a -ladderf having conventional rungs 54, 5,6, 58, and 62. Av

herebefore described exceptfor the ladder rung engaging details on the bar itself. In these drawings, I have shown fwith the endof the bar. This detail of slits 40A a bar 10B which is similar to bar 10 except that the bar 10B has an open bottom area. Flanges 68 extend inwardly from the bottom edges of bar 10B. Bar 10B has slits 40A in its sides which are similar to slits 40' in bar 10, but slits 40A extend upwardly and communicate shown in Figs. 9 and 11. g s

An elongated slit extends down the top of bar 10B Vand extends completely to the end thereof. A plurality' f l ofelongated notches 71 are disposed in bar 10B along slit 70 and each notch communicates-with slit chain length 16, and pin 14 is `adapted to be removably 70 at a point near the center of each notch. f A bracket 72 is slidably mounted in slits 40A. Brack-Q et 72 is comprised of a fiat bar 74 whichrests in slits 40A and -Which hasaV lengthv slightly greater than bar 10B;

Patented May 17, A1960i istl in Fig. ll, a ladder rung 6i) passingthroughrhook portions 78 will engage the vertical legs 76. A rod Si? eX- tends upwardly from the center of bar 74 and terminates above the top of bar 10B. Rod 8i? can extend through either slit 70 or notchesV 7l. A handle 82 is horizontally disposed on rod 80. The distance between hook portions 78 on bracket 72 should be slightly less than the length of rung 60.

The normal operation of my device is as follows: My device will be used in pairs and with each being mounted on a separateV ladder. At the ground level, the operators will loosen the cable 28 so that a slack loop appears therein between the openings 1S and 22 on bar lil. The end of a scaold plank 64 is then inserted into this loop. The exertion of force on cable 28 .in a direction away from opening 22 will pull the cable into tight engagement with lthe plank 64 and the plank will thereupon be inV tight engagement with the bar 10. The operators can then grasp hook member 34and proceed up the ladders to the desired scaiolding height. My device will assume the position shown by the dotted lines in Fig. 2 as it is being carried up the ladders. Having reached the desired scaffolding height, the operators can mount hook member 34 on ladder rung 56 by utilizing thelnook elements 38. lf the slope ofthe ladder 52 does not leave sutlicient working room between the ladder and the wall 66, my device is mounted on the outward side of the ladder as shown` in Fig. l. This is accomplished by lifting the lower end of bar 10, as shown by the dotted lines in Fig. 2, so that this end of the bar rests on ladder rung 601. Pin 14 is then inserted into an appropriate hole 12 in bar 10 to prevent the weight of my device and anyone thereon to slide bar 1t) across the rung 6i?. To insure that plank 64 is level, hook element 36 on hook member 34 can engage any of the links 32 in chain 30, and pin 14 in bar 10 can be inserted into any of the holes l2 in the bar. By merely reversing the position of my unit, and making proper adjustments with chain 3) and pin 14, my device can be similarly mounted on the inside ot ladder 52 as depicted in Fig. 2.

, An important aspect of my on pin 24 about which cable 28 is threaded. Sleeve 26 prevents paint droppings from falling onpin `2dr and thus, sleeve 26 will always be free to rotate thereon. The rotation of sleeve 26 on pin 24 greatly facilitates the operation of cable 28 as it is tightened about plank 64.

The bracket element 44 serves the same function to bar 10A as pin 14 serves to bar 1t). To adjust the position of bracket element 44, the bracket element is rotated about cross bar 46 in the direction of the arrow shown in Fig. 7. This will permit the hoop portion Sil of the bracket to clear the lugs 41 on the top of bar lilA. Then, the bracket element 44 can be slidably moved to a subsequent position so that the hoop portion 5t) engages the invention is the sleeve 26 tapered side of a subsequent lug 41. When my deivce is mounted on a ladder as described above, hook elements 48 on bracket element 44 engage ladder rung 6ft), and the weight of my device bearing against the rung oil prevents the bracket element from rotating as depicted in Fig. 7. Lugs 41 prevent bar 170A from sliding through the bracket which is being maintained in the position shown in Fig. 6. Bar 10A can be mounted on ladders in the same manner that bar 10 was described to be mountedV thereon.

Bar 10B can be mounted on ladders in the same manner that bar 10 was described to be mounted thereon.

The structure on bar 10B shown in Figs. 9, l0 and ll is operated in the following manner: Since bar 74 is longer than the width of bar 10B, bracket 72 can be moved laterally from notches 7l into slit lil or vice versa. Thus, rod 80 on bracket 72 can be selectively moved to any one of the slots 7 1, as the bar 74 is moved through assenso. 'A

slits 40A. This action will permit the operator to place Vthe bracket 72 in any desired position. Bracket72 can even be removed for replacement or substitution purposes by moving bar 74 and rod 80 to the end of bar 10B through their respective slits.r

Hook portions 78 can be mounted on ladder rung 60 and it will be noted that the weight of the scaffold exerted upon bracket 72 will in turn be distributed at the ends and in the middle of the rung by hook portions 78 and legs 76, respectively.V This distribution of weight on the rung is a very important feature of this species of my invention.

From the foregoing, it is seen that my device will accomplish `at least all of its stated objectives.

Some changes may be made in the construction and arrangement of my ladder jack without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims, any modified forms of structure or use of mechanical equivalents which may be reasonably included within their scope.

I claim: Y

l.. In a ladder jack, an elongated bar member, a flexible' means on said bar and the free end of said eXible means.`

2. In a ladder jack, an elongated bar member, a flexible means secured by one of its ends to said bar, the free end of said flexible means movably threaded through said l bar and forming a loop with respect to said-bar whereby said loop can be selectively tightened, said loop adapted to receive a scaolding plank, and adjustable ladder rung engaging means on said bar and the free end of said flexible means.

3. In a ladder jack, an elongated bar member, a flexible means secured by one ofits ends to said bar, means on said' bar for permittingsaid flexible means to form a loop portion with respect to said bar, said means movably securing Vsaidilei/ rible means to said bar whereby the size of said loop can be adjusted, said loop portion adapted to receive a scaffolding plank, and Aladder rung engaging means on said bar and the other end of said flexible means.

4'. In a ladder jack, an elongated bar member, a exible means vsecured by one of its ends to said bar, means on said bar for permitting said ilexible means to form a loop Yportion with respect to said'bar, said means movably securing said flexible means to said bar whereby the size v.of said loop can be adjusted, said loop portion adapted to receive a scaiolding plank, a -hook member removably secured to the other-end of said ilexible means, a bracket element rotatably and slidably mounted on one end of said bar member, ladder rung engaging elements on said bracket element, means on said bar member for selectively holding said bracket element against sliding movement, and means on said bracket element for preventing its rotation when in engagement with a ladder" a bracket element rotatably and slidably mounted on oneV end of said bar member, ladder rung engaging elements on said bracket element, means on said bar member for selectively holding said bracket element against sliding movement, and means on said bracket element for preventing. its rotation when in engagementk with a ladder 6. In a ladder jack, an elongated bar member, a ilexible means secured by yone of its endsto said bar member, a horizontal pin on said bar member, a sleeve rotatably mounted on said pin, the free end of said flexible means threaded over said sleeve to form a loop with said bar member, said loop adapted to receive a scaffolding plank,

and ladder rung engaging means on said bar member and l the free end of said flexible means.

7. In a ladder jack, an elongated bar member, a ilexible means secured by one of its ends to said bar, the

free end of said exible means movably threaded through said bar and forming a loop with respect to said bar Y whereby said loop can' 'be selectively tightened, said loop adapted to receive a scaffolding plank, a ladder rung engaging means on the free end of said ilexible means,'a plurality or" vertical openings in said bar, and a removable pin in one of said openings and adapted to extend therethrough to engage a ladder rung.

8. In a ladder jack, an elongated bar member, a flexible'means secured by one vof its ends to said bar, means on said bar for permitting said flexible means to form a loop portion with respect to saidbar, said means movably securing said ilexible means to said bar whereby the size ofsaid loop can be adjusted, said loop portion adapted to receive a scaffolding plank, a hook member secured to slidabl'y mounted on one end of said bar member, ladder rung engaging elements on said bracket element, and means on said bar member for vselectively holdingv said bracket element against sliding movement.

9. In a ladder jack, an elongated har member, a exfble means secured 'by one of its ends to said bar, means on Said bar for permitting said flexible means to form a loop portion with respect to said bar, said means movably securing said flexible means to said bar whereby the size of said loop can be adjusted, said loop portion adapted to receive a scaffolding plank, a hook member secured to the other end of said flexible means, a bracket element slidably mounted on one end of said bar member, ladder rung engaging elements extending outwardly from the sides of said bracket element, and means on said bar member for selectively holding said bracket element against sliding movement.

References Cited in the tile of this patent UNITED STATES PATENTS 762,304 Goheen .Tune 14, 1904 881,996 Block Mar. 17, 1908 2,488,984 Pennington Nov. 22, 1949

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