US2744795A - Scaffolds - Google Patents

Description

May 8, 1956 J. s. MODONOUGH SCAFFOLDS Filed May 27, 1952 FIG! INVENTOR. JAMES S. MCDONOUGH HTTORNEY United States Patent Ofice 2,744,795 Patented May 8, 1956 SCAFFOLDS James S. McDonough, Hartford, Ill.; Herbert E. McDonough, James E. McDonough, and F. Marvin McDonough, administrators of said James S. McDonough, deceased, assignors to The Finest Scaffold Co., Belleville, 11]., a corporation of Delaware Application May 27, 1952, Serial No. 290,256

2 Claims. (Cl. 304--2) This invention relates in general to scaffolds and, more particularly, to certain new and useful improvements in locking means for preventing unauthorized dislodgment of transverse support members during use of the scaffold.

It is the primary object of the present invention to provide a scaffold having cooperative means associated with the standards and the transverse members which are adapted for locking engagement upon imposition of weight, such as of a workman, on the transverse members or on a platform supported thereby; and which, upon removal of the weight from the scaffold will revert to unlocked relation.

It is a further object of the present invention to provide scaffold locking means which are positive in operation and which are certain to be in engaged position during actual use of the scaffolding.

It is a still further object of the present invention to provide a scaffold which is adjustable vertically and horizontally and which may be adjusted with maximum facility.

It is an additional object of the present invention to provide a scaffold which has a simplicity of parts; which may be most inexpensively manufactured and which is reliable and durable in usage.

With the above and other objects in view, my invention resides in the novel features of form, construction, arrangement, and combination of parts presently described and pointed out in the claims.

In the accompanying drawing- Figure l is an elevational view of a scaffold constructed in accordance with and embodying the present invention;

Figure 2 is a fragmentary perspective view of the scaffold;

Figure 3 is a transverse sectional view taken along line 33 of Figure 2; and

Figure 4 is a transverse sectional view taken substanstantially along line 33 of Figure 2, showing the cross beam in locked position.

Referring now to the drawing which illustrates a preferred embodiment of the present invention, A indicates a scaffold incorporating a pair of standards or uprights 1, 1', each of which comprises a vertically extending channel member 2, preferably of steel, having its legs or side flanges 3, 3', directed inwardly with its web 4 presented to the outer side. Each channel 2 is supported at its lower end by leg braces 5, 5, the lower ends of which are suitably secured as by riveting, to an angle-shaped base member 6, axially normal to the channel member 2. The side flanges 3, 3, of the channel members 2 are each drilled at predetermined intervals, such as 6 inches substantially throughout their extent to provide pairs of aligned apertures, generally denoted 7, 7, for receiving a bolt or pin 8 extending transversely between the flanges 3, 3', and rigidly maintained in position by appropriate means.

Provided for transverse or bridging disposition between the standards 1, 1', is a pair of cross beams or members 9, 10, commonly referred to as stringers, which are preferably fabricated of sturdy wood, such as fir, and

in size comparable to the conventional 2" x 6". Said beams 9, 10, are disposed adjacent their inner ends in side by side relation, being supported therein by means of a plurality of brackets 11 bolted spacedly on said beams 9, 10; said brackets 11 permitting relative slidable movement of the beams 9, 10, for mutual extension or contraction to accommodate the selected distance between the standards 1, 1'.

On the upwardly and downwardly presented surfaces of each of the beams 9, 10, at their outer ends, there is secured as by carriage-type bolts 12, strap members 13, 13', respectively, which extend beyond the outer end faces of the beams 9, 10, and spacedly therefrom are bent downwardly in hook formation to provide depending tongues 14, 14. The apertures 7, 7, in the channel members 2 are located with reference to the inner face of the web 4 so that the distance between the bolts 8 and the web 4 is slightly in excess of the thickness of the tongues 14, 14', which are preferably of inch metal.

In usage, the standards 1, 1', are presented in spaced apart relation with the distance therebetween depending upon the particular work to be accomplished. The beams 9, 10, are commensurately extended and are presented for insertion of the depending tongues 14, 14', downwardly between the web 4 and vertically adjacent bolts 8, as may best be seen in Figure 3. Since the space between the bolts 8 and the web 4 is but slightly greater than the thickness of the tongues 14, 14', it is requisite that the beams 9, 10, be held in substantially horizontal position during the insertion step to prevent any impeding contact between the tongues 14, 14, and the web 4. The plurality of vertically aligned bolts 8 in each standard 1, 1', permit vertical adjustability of the beams 9, 10, so that scaffold boards or a platform 15 supported thereon may be conveniently positioned with reference to the work. Any desired number of the scaffolds A herein described may be used to support a platform 15 adequate for the particular working area.

When the scaffold A is in usage with a workman or workmen on the platform 15, the beams 9, 10, will be subjected to a downwardly directed force due to the weight of the workman or workmen which force is transmitted directly from the platform. This force will cause the beams 9, 10, to cant or to tilt downwardly at their inner ends, which, as indicated above, are not supported by any external means. This canting movement will cause a relative upward rocking of the outer end portions of the beams 9, 10, with the tongue 14' being brought into surface abutting relation with the inner face of the Web 4 (see Figure 4). Upon such surface engagement further canting or tilting of the beams 9, 10, is prevented and the same are thereby positively held against untoward dislodgment. The tongues 14, 14, are stable and are resistant to any deformation by such tight locking engagement with the web 4. It will thus be seen that the lock-actuating force is the weight of the workman or workmen on the platform 15, whereby whenever the scaffold A is in use, the beams 9, 10, will be locked. By this invention, the security of the workmen is certain since there is no need of any conscious locking procedure as would be required with various types of latches and the like heretofore well known in this art. The workmen may thus move across the platform 15 without concern as to the safety of the scaffold A since his very presence on thesaid platform assures locking engagement.

When the scaffold A is not in use, the absence of any weight upon the beams 9, 10, will permit same to return to normal horizontal disposition with the tongues 14, 14', reverting to the original position as shown in Figure 3. I

In view of the foregoing, it will be readily seen that the scaffold A comprises but few parts which may be easily assembled and disassembled without the exercise of skill on the part of the user. Additionally, the component parts are so designed as to. require a minimum of storage space when the scaffold A is disassembled and. which are relatively light in weight for facile transportability.

It should be understood that changes and modificain the form, construction, arrangement, and combination of the several parts of the scaffold may be made and substituted for those herein shown and described without departing from the nature and principle of the present invention.

What I claim and desire to secure by Letters Patent 1. A scaffold comprising a pair of spaced apart, vertically presented channel members, each channel member having side flanges and a web, a plurality of vertically aligned, spaced bolts extending transversely between the side flanges of each channel substantially throughout its length, a beam, and vertically spaced bolt-engaging members secured on the upper and lower surface of said beam at each of its ends, said bolt-engaging members at each end having. vertical depending tongue-like portions at their extremities for downward insertion between a bolt and the channel web of the adjacent channel member for normal disposition in planar parallel relation to the channel web, the tongue-like portion of the lowermost hook member projecting downwardly below the beam, said bolts being spaced from the channel web a distance slightly greater than the thickness of the depending portions of the bolt-engaging members whereby the same will normally be spaced therefrom and upon the imposition of weight on the beam the depending portion of at least one of said members at each end of the beam will be moved into lockingly abutting relation with the adjacent channel web, said members having a width less than the distance between the channel side flange for being normally spaced therefrom.

2. A scaifold comprising a pair of spaced apart, vertically presented channel members, each channel memher having side flanges and a web, a plurality of vertically aligned, spaced bolts extending transversely between the side flanges of each channel substantially throughout its length, a pair of strap members secured respectively on the upper and lower surface of said beam adjacent each of its ends and each having a horizontal portion projecting beyond the adjacent end of the beam for resting disposition upon a bolt, said strap members each further having at the outer end of its horizontal portion a downwardly bent tongue portion for downward insertion between a bolt and a channel web of the adjacent channel member, the tongue-like portion of the lowermost hook member projecting downwardly below the beam, said bolts being spaced from the channel web a distance slightly greater than the thickness of the tongue portions of the strap members whereby the same will normally be spaced therefrom and upon imposition of weight on the beam the tongue portion of the lower strap member at each end of the beam will be rocked in a tight surface abutting relation with the adjacent channel web, said strap members having a width less than the distance between the channel side flange for being normally spaced therefrom.

References Cited in the file of this patent UNITED STATES PATENTS 118,424 Barlow Aug. 29; 1871 118,553 Redick Aug. 29, 1871 153,270 Newhard July 21, 1874 405,195 Aryes June 11, 1889 768,295 Palfrey Aug. 23, 1904 843,456 Higbee et al. Feb. 5, 1907 924,353 Horton June 8, 1909 2,549,212 Lane Apr. 17, 1951

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