US2808297A - Separable connections or cam locks - Google Patents

Description

Oct. 1, 1957 D. I. WEISZ 2,808,297

SEPARABLE CONNECTIONS OR CAM LOCKS Filed Nov. 9, 1955 United States Patent SEPARABLE CONNECTIONS 0R CAM LOCKS Daniel I. Weisz, Ellwood City, Pa., assignor to Beaver- Advance Corporation, Ellwood City, Pa., a corporation of Pennsylvania Application November 9, 1955, Serial No. 545,863

3 Claims. (Cl. 304-40) This invention relates to knock down scaffolds and particularly to an improvement on the connection or cam lock shown in Patents 2,435,171 and 2,483,862 for securing the diagonal braces or stays to the spaced rectangular end frames of such scaffolds in order to form a rigid selfsustaining structure.

Knock down scaffolds are used extensively but the problem of quickly assembling and removing them has never been completely solved. Various types of connections or cam locks have been heretofore proposed for securing brace members to end frames but none have proven to be entirely a solution to the problems.

It is an object of the present invention to provide a positive locking device for scaffolding.

Another object of this invention is to provide a separable connection for securing diagonal braces to the rectangular end frames of knock down scaffolding.

A further object of this invention is to provide a separable connector or cam lock providing preferably a gusset plate on a scafiold end frame having a keyhole opening therein, a pair of spaced retaining rings on the brace adapted to pass on opposite sides of the gusset plate, a collar rotatable between the rings to pass into the key hole opening, operating means for rotating the collar and locking means automatically engageable by gravity within the key hole slot.

While certain objects and advantages of this invention have been described above, other objects and advantages will become apparent from a consideration of the following description and the accompanying drawings in which:

Figure 1 is a partial elevation of a scafiold end frame and bracing member according to this invention with the connector or cam lock in insertable position.

Figure 2 is a partial elevation as in Figure 1 with the connector or cam lock in locked position.

Figure 3 is a section on the line IIII of Figure 2.

Figures 4 4 and 4 are an exploded view of the parts making up the connector shown in Figures 1 through 3 with the parts in isometric views.

Referring to the drawings there is illustrated a rectangular end frame for a knock down scaffold having vertical posts 11 spaced apart by horizontal "beams 12 welded together. The end frames 10 of a multiple section scaffold are spaced apart and connected by diagonal braces 13 extending from one frame to another. Gusset plates 14 are welded to the posts and beams in the corner of the frames. Keyhole slots 15 are provided in the gusset plate 14, each slot having a restricted neck 16 and an eye 17.

Each diagonal brace 13 is provided at its ends with spaced retaining rings or discs 18 connected by a shaft 19. A cylindrical collar 20 having a pair of axially extending segmental lugs 21 on each side is rotatably mounted on the shaft 19. An operating handle 22 having an elongated opening 23 therein with parallel flat sides 24 adapted to engage the edges of one pair of lugs 21 is slidably fitted on one set of such lugs 21. One of the discs 18 is provided with opposed recesses 25 into which a latching lug 26 on the handle fits to hold the handle against rotation. The other pair of lugs 21 is adapted to slide through the restricted neck 16 of the key hole slot into the eye 17 where turning of the handle 22 rotates them in the eye 17 and prevents the removal of the diagonal brace 13.

The operation of these scaffolding members is believed to be apparent from the foregoing description; however a brief description follows: The handle 22 is turned 'to the horizontal position (Figure 1) with the lugs 21 turned to pass through the restricted neck 16. When the collar 20 passes into the eye 17, the handle 22 is turned to the vertical position (see Figures 2 and 3) thereby rotating the lugs 21 to prevent removal from the eye 17. When the handle 22 is turned to the vertical position the latching lug 26 enters one of the recesses 25 by reason of the Weight of the handle and the elongated hole 23 sliding on the lugs 21. When the handle is in this position, it cannot be accidentally turned to release the brace from the gusset plate.

When it is' desired to release the brace the handle 22 is moved in the vertical direction and rotated to the horizontal position in which the lugs 21 are slidable through the restricted slot 16. V

While there is illustrated and described but a single embodiment of this invention it will be understood that it may be otherwise embodied within the scope of the following claims.

I claim:

1. A separable connection or cam lock for securing diagonal braces to the rectangular end frames of a knock down scaffold, comprising a gusset plate on the end frames having a keyhole slot therein with an enlarged circular eye and a restricted opening to the edge of the gusset plate, a pair of spaced retaining rings on the end of the brace member adapted to pass on opposite sides of the gusset plate and connected by a member adapted to pass through the restricted neck of the keyhole slot, a collar rotatable between the retaining rings, a pair of arcuate lugs extending axially of the collar on opposite sides of the'connecting member between the retaining rings, said lugs being dimensioned to enter the restricted neck when turned in one position and held against removal when turned degrees from said one position, a handle having an elongated opening therein fitted over said pair of lugs and slidable diametrically thereon, said handle engaging the lugs to rotate the collar on the connecting member, an axially extending latching lug on the handle and a cooperating recess in one of the retaining rings adapted to receive the latching lug whereby the collar is locked against removal when the handle is moved diametrically of the connecting member to bring the latching lug into the recess and is released for rotation when the handle is moved in the opposite direction on the lugs to lift the latching lug from the recess in the retaining ring.

2. A separable connection as claimed in claim 1 wherein the collar is provided with .a pair of arcuate lugs extending axially on'each side of the collar, one of said pair adapted to enter the restricted neck when turned in one position and to be held against removal when turned 90 degrees from said one position and the other pair receiving the elongated opening of the handle and engaged for rotation thereby.

3. A separable connection as .claimed in claim 1 wherein the chord of each arcuate lug is substantially equal to the diameter of the connecting member between the lugs and the width of the restricted neck of the keyhole slot.

References Cited in the file of this patent UNITED STATES PATENTS 1,130,470 Booth Mar. 2, 1915 2,483,862 Weisz Oct. 4, 1949 2,665,953 Maroney et a1. Ian. 12, 1954

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