US2162651A - Support for scaffolds - Google Patents

Description

June 13', 1939.

P. THOMSON SUPPORT FOR SCAFFOLDS 2 Sheets-Sheet 1 Filed Oct. 29, 1938 INVENTOR. PETE? Thomson.

2 ATTORNzS.

BY a June 13, 1939- P. THOMSON 2,162,551

SUPPORT FOR SCAFFOLDS Filed Oct. 29, 1938 2 Sheets-Sheet 2 III/#147,174

INVENTOR.

PETE? Thomson.

E E m I Patented June 13, 1939 UNITED STATES PATENT OFFICE '7 Claims.

The present invention relates to trestles or scaffold supports and the primary object of the invention resides in the provision of a support for scaffolding which is of extremely simple construction, yet exceedingly sturdy and capable of supporting heavy loads.

A further object of the invention is to provide a folding scaffold support which may be quickly and easily set up and taken down, and when not in use, may be folded into compact form for shipment or storage.

A further object resides in, the arrangement for retaining the support in its folded condition by means which also serves to secure the support to a scaffold beam.

A further object is to provide a scaffold support which may be set up for use or taken down without requiring any tools, and which is adjustable to stand level and steady on uneven footing.

A still further object resides in the specific construction of the extensible supporting legs and the clamping means for securely retaining the legs in adjusted position against relative movement between the leg sections.

A still further object resides in the specific formation of the upper ends of the angle iron leg members whereby the scaffold beam is firmly gripped between the legs without any twisting or canting of the legs due to the clamping force.

Other objects and advantages of the invention will be apparent from the following detailed description, taken in connection with the accompanying drawings, forming a part of this specification and in which drawings:

Figure 1 is an elevation of the trestle or support set up for use with a scaffold beam supported thereby.

Figure 2 is a side view on a reduced scale of the showing in Figure 1.

Figure 3 is a rear view of the support or trestle in a folded position.

Figure 4 is an edge view of the trestle folded as in Figure 3.

Figure 5 is an enlarged section substantially on the lines 5-5 of Figure 4.

Figure 6 is a fragmentary perspective view of the upper end portion of one of the supporting legs.

Figure 7 is an enlarged section on the line 1-1 of Figure 3.

Figure 8 is a perspective view of a socket forming strap member of the clamping means for the extensible legs.

Figure 9 is a perspective view of a clamping shoe or block of the clamping means.

In the drawings and wherein like reference characters designate corresponding parts thruout the several views, the letter A may designate generally the improved trestle or support and B a wooden scaffold beam or plank supported by the trestle.

The trestle A comprises a metal frame embodying a pair of upwardly converging extensible supports I0 each of which includes an upper main section or leg I l and a lower extension section or leg I2 nestled in the section I I in a manner to permit relative longitudinal movement for varying the height of the trestle. These leg sections I I and I2 are formed from angle iron, with the extension section I2 being slightly smaller in size and slidably fitting in the main section II as shown in Figures 5 and '7. As will also be seen from Figures 5 and 7, the leg sections I I are what are known as square root angles, that is, the flanges form a sharp internal corner, while the leg sections I2 may be ordinary angle iron having a slightly rounded internal corner and a sharp external corner.

The legs II are arranged with the flanges I3 in confronting relation, and the flanges I4 thereof directed toward one another whereby the upper extremities of the flanges l4, provide sharp corners or biting edges I5 which are adapted to grip and bite into opposite faces of the wooden beam B. An upper end portion of the flange I3 is bent inwardly over the upper end edge of the flange I4 as at IE to form a stop flange having a straight bearing edge I'I perpendicular to the flange I 4. This bearing edge I1 is spaced slightly from the biting edge I5 and is adapted to engage thruout its length, a face of the beam B and prevent twisting strains on the legs when clamped upon the beam.

The leg sections II are connected adjacent their lower ends by a solid or one-piece spacer or cross bar I8 having its ends pivotally secured to the legs by rivets I9 whereby the upper portions of the legs are freely movable toward and from one another. As shown in Figure 5, the rivets I9 have beveled heads countersunk in the flange I4 to lie flush with the inner surface of the flange. The bearing for the rivet I9 is formed by punching the metal of the flange to form a short sleeve like projection which slightly spaces the cross bar I8 from the flange.

Adjustably connecting the upper portions of the legs II is a combined support and clamping means embodying a carriage bolt 20 having a squared shank portion adjacent the head 2I fitting in a square opening in the flange I 3 of one of the legs I I and its threaded end 22 extending thru an opening in the flange l3 of the other leg II. The bolt 20 is bent substantially midway of its ends forming a V-seat for the beam B to rest in. Threaded upon the end 22 of the bolt outwardly of the flange I3 is a hand nut 23 having a hand lever 24. Turning of the nut 22 by its lever 24 will draw the upper ends of the supports I0 toward each other so as to firmly grip the beam B between the upper ends of the legs II with the biting edges I5 biting into the beam and the bearing edges I1 bearing against opposite faces of the beam. Provided on the shank of the bolt 20, inwardly of the flanges l3, are two pins or the like 25 forming stops against which the flanges I3 abut and limit movement of the legs I I toward one another when the trestle is folded as in Figure 3. These stops 25 are so spaced that when the hand nut 23 is turned tight in folding the trestle, the biting edges I5 will be slightly spaced apart to prevent being damaged.

Pivotally connected at one end as by a rivet 26 to each of the legs II at a point adjacent the lower end of the leg, are straight diagonal brace rods 21 having free ends adapted for clamping engagement with the beam B at a point spaced from the supports I6. As shown in Figure 5, the rivets 26 have beveled or countersink heads which are countersunk in the flange I3 to lie flush with the inner surface of the flange. The bearing for the rivet 26 is formed by punching the metal of the flange I3 to form a short sleevelike projection which slightly spaces the brace rod from the flange and forms somewhat of a loose pivotal connection. This loose pivotal connection of the brace rods 21, together with the slight spacing of the pivoted ends from the flanges I3, permits the braces to change their angular relation when moved without creating an objectionable binding action at their pivot points.

Extended thru suitable openings adjacent to the free ends of the brace rods 21 is a clamping bolt 28 provided with a hand nut 29 having a hand lever 36. The hand nut 29 when tightened by the lever 38 serves to draw the free end of the brace rods together and into clamping engagement with the beam B when the trestle is set up for use. The clamping bolt 28 as shown in Figures 3 and 4, is so spaced from the pivot 26 of the brace rods 21 as to be disposed slightly beyond the beam engaging ends of the supports II] when the trestle is folded, thereby allowing the brace rods to overlie their respective supports as shown in Figure 4.

The free ends of the'brace rods 21 are provided with inwardly directed pointed calks or spurs 3| having shanks extended thru openings in the brace rods and upset to form driving heads 32 which may be tapped with. a hammer or the like for firmly forcing the spurs into the wooden beam in addition to the clamping action of the bolt 28 and securely attach the braces to the beamagainst movement.

Each of the supports I6 is separately adjustable for varying 'the "height of the trestle and for leveling the trestle on uneven footings. The clamping means for the extensible supports i6 comprises a metal strap member 34 connected diagonally-across-the lower portion of the upper legs section II as by welding the ends of the strap'member to theedges of the flanges I 3 and I4 as shown'inFigure 7. The intermediateportion of the strap member 34 is drawn in at the side edges of the member to form a socket 35 having parallel side walls 36 and a top wall 31. Provided in this top wall 31 is an opening 38.

Adapted for co-action with the strap member 34 is a right triangular clamping shoe or block 40 having grooved right angularly gripping faces 4| and a diagonal face 42. The clamping shoe 4!] is adapted to be disposed inwardly of the strap member 34 and is provided at each end of the face 42 with side or retaining extensions 43 which slidably engage the outer surfaces of the side walls 36 of the strap member for constraining the clamping shoe to movement toward and from the strap member. Provided in the diagonal face '42 of the clamping shoe is a socket 44 adapted to receive the inner threaded end portion 45 of an L-shaped clamp screw 46. The threaded portion 45 of the clamp screw extends thru the opening 38 in the strap member 34 and is threaded thru a pressure nut 41 disposed in the socket 35 and held against rotation between the parallel side walls 36 of the socket. As shown in Figure '7, when the clamp screw is threaded inwardly, the grooved gripping faces 4| of the clamping shoewill be forced into engagement with the flanges of the leg I2 and clam-p these flanges firmly against the flanges I3 and I4 of the upper leg section II. The specific formation of the leg sections II of square root angles insures a positive and firmer gripping of the leg section l2 with the leg section II when the clamp is tightened.

The lower leg section I2 which is slidable inwardly of the upper leg section II has one of its flanges bent over the end edge of its companion flange to form a rest flange or foot 48.

In assembling the supports II), the clamp screw 46 is first backed off and the clamping shoe placed in position beneath the strap member 34. The leg section I2 is then slid between the shoe and the flanges of the leg section II After the leg sections H and I2 are so assembled and with the clampingshoein place, a retaining pin 50 which may be in the form of a screw nail is then driven into a suitable opening adjacent the upper end of the leg I2 and forms a stop engageable with 'an end of the shoe 4!] and prevents full withdrawal of the leg I2 from beneath the clamping shoe when extending the supports Hi. When the leg sections II and I2 are assembled as in Figure '7, the clamping shoe 40 will be retained in place even though the clamp screw 46 is completely removed.

In setting up or erecting the trestle, the scaffold beamis placed between the upper ends of the supports Hland restin the bend of the com bined supporting and clamping bolt 20. Thehand nut 23 is then tightened for clamping the beam between the upper ends of the supports with the biting edges I5 biting into the beam and the bearing edges I'I engaging oppositeside faces of the beam, as'in Figure l. The bearing edges I'I thru contact longitudinally of thebeam, will prevent canting or twisting of the leg sections II when considerable clamping pressure is applied by the clamping means. The brace rods 21 are then swung on their pivots I9 to straddle the beam at their free ends and after which the clampingbolt 28 is tightened for clamping the free ends of the brace rods upon the beam. To assist in firmly engaging the free ends of the brace rods with the beam, the heads 32 of the calks -3I maybe tapped with a hammer for driving the'pointed calksinto the-beam. 'If the-support IO has previously been adjusted-to-height, the final adjustment of the legs may be made for leveling the trestle and providing a firm footing for the legs. When collapsing or folding the trestle for storage or shipment, the lower leg sections l2 are first slid into the leg sections I l and retained by means of the clamping shoe 40. The hand nut 23 is then turned up until the flanges I3 of the leg II are drawn up tight against the stops 25, and which occurs prior to engagement of the biting edges l5. The convergent brace rods 21 are then swung so as to overlie the flanges l3 as in Figure 4 and. then the clamping bolt 28 tightened to clamp the brace rods upon the supports Ill. Thus, the clamping bolt 20 serves the dual purpose of supporting the scaffold beam and also clamping the supports upon the beam, while the clamping bolt 28 serves the dual purpose of clamping the brace rods to the scaffold beam and also clamping the brace rods upon the supports I when the trestle is folded.

Changes in detail may be made to the form of invention herein shown and described, without departing from the spirit of the invention or the scope of the following claims.

I claim:

1. In a scaffold beam support, a support comprising upper and lower angle iron leg sections,

a sheet metal strap member connected across the flanges of the upper leg section and having its intermediate portion formed into a socket, a nut held against rotation in said socket, a right triangular clamping shoe retained in position by the strap member for engagement with the lower leg sectionand having a socket in its diagonal face,

and a clamping screw threaded thru the nut and having its free end engaging in the socket of the clamping shoe for clamping the leg sections in longitudinally adjusted relation.

2. In a support for scafiold beams, an extensible leg including upper and lower leg sections of angle-shape formation and with the lower leg section nested in the upper leg section, and clamping means for retaining the leg sections in longitudinally adjusted relation comprising a strap member secured to and extending across the inner side of the upper leg section, a socket formed in the strap member, a nut retained against rotation in the socket, a right triangular clamping shoe for engaging in the angle of the lower leg section, and a clamping screw having a threaded portion threaded thru said nut and acting upon the clamping shoe for forcing the shoe into binding contact with the inner leg section.

3. In a clamp for extensible supports of angle iron shape and having one angle iron nested within the other, a strap member secured across the flanges of the outer angle member, a socket formed in the strap member, a nut loosely retained against rotation in the socket, a right triangular clamping shoe held against displacement by the strapmember and adapted for clamping engagement with the inner angle member, and a clamping screw threaded thru the nut and acting upon the clamping shoe for clamping the shoe against the inner angle member.

4. In a scaffold beam support, a frame including. extensible supports each comprising an upper angle-shaped leg section and a lower angleshaped leg section nested in the upper leg section, clamping means carried by the lower portion of the upper leg section including a clamping shoe, a clamping screw for moving the shoe into clamping engagement with the lower leg section, and a pin projecting from one flange of the lower leg section and engageable with said clamping shoe for limiting outward movement of the lower leg section, said lower leg section when nested in the upper leg section preventing displacement of the clamping shoe should the clamping screw be removed.-

5. In a scaffold beam support, a pair of upwardly converging legs, a pivotally connected spacer bar for the lower portions of the legs, a clamping bolt adjacent the upper ends of the .legs having angularly disposed portions one of which is provided with a head and the other portion with a threaded section, a hand nut threaded upon the threaded section for drawing the legs together, and a pin in each angular portion of the bolt and limiting movement of the legs together at their upper ends 6. In a scaifold beam support, a frame including a pair of supports, clamping means for drawing the supports together at their upper ends into clamping engagement with the scaffold beam, a brace rod pivoted at one end to each support, a clamping bolt for the free ends of the brace rods for clamping the free ends upon a scaifold beam, and a pointed calk at the free end of each brace rod and having shanks passed throuthe rods and headed up at the outer sides of the rods to form driving heads for forcing the calks into the beam.

'7. ,In a s'caifold beam support, a frame including a pair of upwardly converging angle iron legs each having the upper end of the free edge of one flange providing a biting corner for biting into a scaffold beam, and the upper portion of the companion flange of the leg being bent to overlie the upper edge of said first mentioned flange and terminating short of the free edge of said first flange to form a straight bearing edge extending normal to the major plane of the frame at one side of the biting cornerfor bearing contactwith the scaifold beam longitudinally of the beam.

PETER THOMSON.

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