US2891819A - Scaffolding jack - Google Patents

Description

June 23, 1959 5. JACKSON SCAFFOLDING JACK 2 Sheets-Sheet 1' Filed Dec. 27, 195? June 23, 1959 G. w. JACKSON SCAFFOLDING JACK 2 Sheets-Sheet 2 Filed Dec. 27. 1957 United States Patent SCAFFOLDING JACK George Wilbert Jackson, Vancouver, British Columbia,

Canada Application December 27, 1957, Serial No. 705,529 4 Claims. (Cl. 304-32 This invention relates to jacks, having referenceto device to be used in setting up scaffolding.

Scaifolds for building and like purposes are more frequently constructed of material secured together by nailing or by clamps. Brackets of various kinds have also been employed. It is with such brackets, or jacks, that the present invention is concerned and it is the purpose of the. invention to provide a simple type of jack by which materials commonly used in building may be employed in erecting the scaffold, and in which the scaifold can easily be erected or dismantled.

For this I provide a jack for scaffolding and for like purposes designed to be clamped on legs of common scantling and to engage a cross bar on which planking may be laid, and further to be easily set up or dismantled and to be secure in its engagement of the legs and cross bar. The jack is also adapted to be used in a multiple of ways for building and like purposes where scaffolding is used.

In the drawings, which illustrate a preferred embodiment of the invention,

Fig. 1 is a side view of the jack taken by itself, shown with the connecting links locked as when the jaws are in position to engage a cross bar, and with the side clamps open.

Fig. 2 shows a side view of the jack mounted on supporting legs and with the jaws open preparatory to engaging a cross bar, the jack being shown broken away in part.

Fig. 3 is a side edge view of a jack shown as part of a scaffold in attachment to a wall.

Fig. 4 is a top view of the jack as shown in Figure 1.

Fig. 5 is a perspective view showing the construction of a trestle using my improved scafiolding jack, and in cluding a hand rail and rail clamp, shown partly broken away and with the one jack and scantlings indicated in phantom.

Fig. 6 shows an end view of a scafiEold in which a pair of jacks (would be used for each end of the scaifold connected by a cross bar.

Fig. 7 is an enlarged front view of a rail clamp taken by itself.

Fig. 8 is a side view of a rail clamp attached to a scafiolding scantling engaging a rail, shown with the scantling broken away.

Referring to the drawings, the jack is made up of two pivotally connected halves, each formed of a side channel bar 1 adapted for sliding engagement of a scantling, preferably a length of two by four. At the upper end of the side bar 1 is fixed a U-shaped bracket 2, from which a jaw formed of two jaw members 33 depends. The jaw members attach at their lower ends to braces 4, one to each side of the bar 1, the braces being fixed, as by welding, to the side bars and the ends projecting beyond the side bars and jaw members. At the lower ends the braces 4 carry a pin 5 on which pivots an eccentrio 6 providing a hand grip 7 and a toothed working 2,891,819 C t rem-.

2 face 8 for clamping engagement with a length of scantling 9. p

At their upper ends the side braces 4 engage a pin 5 on which the two halves'of thejack pivot to move the opposing jaws together or apart in order to grip or release a cross bar that would form a support for seatfolding planks 12. At the lower ends. the side bars are movable to open and close. the jaws by links 13 and 14', each pivoting at 15 to a side bar 1 and together one pin 16. The links are of channel iron, the oneoversize of the other to overlap.

In the use of the jack, by pulling upon the links 13 and 14 the lower ends ofthe side bars 1 of a jack formed of connected halves are drawn together as in Fig. 2, and this causes the jack halves to. pivot on the pin 10 and divergingly spread the jaws. The cross barll is firmly gripped when the links 13 and 14 are pressed down and locked together, as in Fig. 1, forcing the lower ends of the bars 1 apart and the jaws together.

In erection of a scaffold, using thejack', this may be done in various ways, one of these being set up in Fig. 3 in which the inner end of the cross bar engaged by the jaws is attached to a wall by a bracket 17 and the planks 12;laid on the cross bars of two. 'sudh'jacks that are spaced apart.

The jack can also be used to form a trestle, the showing in Figure 5 illustrating this and in which two jack assemblies would be employed engaging a cross bar therebetween. On the brackets 2 of the jacks may be laid one or more planks 18. In this showing there is also provided a rail 20, for mounting which on the scaffold or trestle a rail clamp is required, the rail being attachable on extensions of the scantlings 1.

The rail clamp consists of spaced side plates 21, back plate 23 adapted to lie against the upright 1, and a further back plate 24 spaced from the upright to seat the rail bar 20. On the side plates 21 is mounted a clamping member 22 on a pin 25, this clamping member corresponding to the clamps 6 and being adapted for engagement of the scantling extensions by which the rail is to be carried.

In Fig. 6 is shown a further arrangement in which each end of the trestle would be made up of a pair of jacks with connecting cross bar, and between this and a similar pair of jacks with cross bar planks 19 would be laid on the cross bars. This also indicates how a scaflold or trestle could be erected on a sidehi-ll by raising one of the scantlings to support the connecting cross bar on a level. Also the jacks permit easy variation of the height of a scaffold by moving them up or down on their supporting scantlings.

While I have herein disclosed a preferred embodiment of the jack, it is obvious that changes would be readily conceivable, but in so far as such changes come within the spirit and scope of the invention they would be considered a part hereof.

Having thus particularly described and ascertained the nature of my said invention what I claim and wish to secure by Letters Patent is:

1. In a scaffolding jack providing a pair of side bars adapted to receive lengths of scantling therein to form legs for the jack and including clamping means for engagement of the lengths of scantling in the side bars, inwardly directed brackets carried by the upper ends of the side bars, jaws attached depending from the brackets, and means by which the pair of side bars may be pivotally connected to form the jack, said means comprising a pair of brace bars for each side bar attached fixed to the lower end portion of the side bar and the depending jaw, means pivotally connecting the upper end portions of the brace bars of a pair of side bars to form the jack, and link means pivotally connecting the lower ends of said side bars adapted for effecting movement of said side bars together or apart and to lock said side bars apart.

2. A scaffolding jack comprising two channel iron side bars adapted to slidingly receive lengths of scantling thereinto provide legs for the jack, inwardly directed brackets fixed to the upper ends of the side bars, depending jaws fixed to the brackets, diagonal brace bars fixed to the lower end portions of the jaws and the side bars, a pin attaching the upper ends of opposing brace bars to form a pivotal connection therebetween, link means providing a pivotal connection for the lower ends of the side bars by which said side bars may be moved together or apart, and clamping means carried by the lower ends of the brace bars for efiecting engagement of the side bars on lengths of scantling.

3. A scaffolding jack comprising mating halves each consisting of a side bar providing a channel in which a length of scantling is receivable to be endwise slidable therein, a bracket carried by the upper end of the side bar, a pair of toothed jaw members fixed depending from the bracket spaced apart, a pair of brace bars attached fixed to the lower portions of the side bar and to the lower ends of the jaw members, said brace bars projecting beyond the side bar and jaw members, clamping means carried by the lower projecting ends of the brace bars adapted for engagement of a length of scantling in the side bar, a pin through the upper ends of the brace Cit bars and on which pin two mating halves of the jack may pivot, and link means pivotally connecting the lower end portions of the side bars and adapted for moving said side bars together or apart pivoted on the pin through the upper ends of the brace bars, said link means being adapted to lock the lower end portions of the side bars spaced apart.

4. A scaffolding formed of jacks and lengths of scantling in accordance with claim 3 and including side rails, the lengths of scantling on the side or sides on which rails are to be provided extending above the jacks and clamps for attachment of the rails to the scantling extensions, said clamps each providing side and back plates defining a slideway in which a length of scantling is receivable, clamping means on the side plates adapted to engage the clamp on the length of scantling, and a further back plate attached to the side plates spaced to leave an interval between said further back plate and a length of scantling and in which interval a rail bar is endwise receivable.

References Cited in the file of this patent UNITED STATES PATENTS 318,896 Hanssen May 26, 1885 1,682,671 Gooding Aug. 28, 1928 2,561,864 Hollywood July 24, 1951 2,705,174 Squire Mar. 29, 1955

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