US2665953A - Knockdown scaffold having safety lock - Google Patents

Description

1954 c. F. MARONEY ETAL KNOCKDOWN SCAFFOLD HAVING SAFETY LOCK Filed Sept. 13, 1951 IN VEN TORJ Patented Jan. 12, 1954 2,665,953 KNOCKDOWN soAr'lgc r n HAVING SAFETY Clair F. Maroney, Daniel I. Weisz, and Ralph W. McGrew, Ellwood City, Pa., assignors to Beaver Art Metal Corporation, Ellwood City, Pa., a corporation of Pennsylvania Application September 13, 1951, Serial No. 246,366

2 Claims. (Cl. 304-40) This invention relates generally to knockdown scaffold and, in particular, to an improvement of the connector for securing diagonal braces or stays to the spaced rectangular end frames of such scaffolds in order to form a rigid self-sustaining structure.

Knockdown scaffolds are used extensively but as made prior to this invention they were not quickly and easily assembled but required considerable time and labor as well as the use of tools for erection and dismantling.

It is the object of this invention to provide a positive locking device for use with a scaffold.

In a preferred embodiment of the present invention, there are provided gusset plates at the junction of the horizontal and vertical members of the end frames. These plates are provided with keyhole slots extending thereinto from an exposed edge, adapted to receive the end of a brace or a stay. There is also provided a brace with a head at each end and a flange spaced inwardly thereof. Between each head and flange there is rotatably mounted a collar having a segmental fiange and a handle for turning it. The segmental flange is adapted to enter the restricted outer neck of the keyhole slot when turned to the proper position and to lock the brace in the gusset plate when the segmental flange is turned perpendicular to the position for entering the keyhole slot. A locking member is slidably mounted in the segmental flange handle so as to be slidable transversely to its plane of rotation. In the locked position the locking member lies beneath the gusset plate so as to be adjacent the lower edge thereof and prevent the rotation of the handle to the unlocked position.

A more complete understanding of the inven tion may be obtained from the following detailed description and the drawings in which:

Figure 1 is a partial elevation of one end of a scaffold frame.

Figure 2 is a section through a horizontal member of one frame showing the ends of braces secured thereto.

Figure 3 is a section through a horizontal member of a different frame embodiment showing the ends of braces secured thereto.

Figure 4 is a section of the horizontal member and gusset plate of Figure 2.

Figure 5 is a section on the line 5-5 of Figure 4.

Figure 6 is a front elevation of the locking collar.

Figure 7 is a side elevation thereof.

Figure 8 is a side elevation of a segment of 2 brace member showing locking collar in place thereon.

Figure 9 is a top plan View of the locking member of the invention.

Figure 10 is a side elevation thereof.

Referring to the drawings there are illustrated end frames i0 composed of posts l and beams l2 welded together. While both the posts I! and beam I? are shown as fabricated from tubular members they may be made of any other section or combination of sections. The end frames Ill of a multiple section scaffold are spaced apart and connected by braces or stays l3 extending from one end frame to another. The braces l3 are shown in the drawings as round bar stock but they may be of any other desired section. Gusset plates M are welded to the posts and beams in the corners of the frames. Keyhole slots l5 are provided in the gusset plates, each having a restricted neck It adjacent an exposed edge of the plate and an eye I! spaced from the edge. The neck 5 is slightly greater in width than the diameter of the braces l3. As shown in Figures 2 and 3 there are gusset plates in each corner of the frame, which plates may be parallel to each other (Figure 2) or in the form of a V (Figure 3).

Each brace l3 has a head H3 in the form of a disc welded thereon or upset from the body of the brace. A flange I9 is welded at each end of the brace a short distance inwardly of the head I8. A collar 20 having a manipulating lever or handle 2| is rotatably mounted on the brace between each head l8 and flange I 9. The collar 20- has a segmental portion 22 extending laterally thereof, which portions are of such width that they will pass through the necks of the slots E6. The eyes ll of the slots have a diameter slightly greater than the outside diameter of the segmental portions 22 so as to permit rotation of the collars and segmental portions after they have entered into the eyes of the slots.

The method of operation of these scaffolding members is believed to be apparent from the foregoing description; however, a brief description is as follows: The handles 2| are turned to the horizontal position (chain lines, Figure 5). This alines the segmental portions 22 with the necks of the slots I6 and permits them to pass therethrough. When the ends of the braces have thus been brought into the eyes of the slots, the handles 2| are turned down to the vertical position. The braces are thus centered in the eyes with the segmental portions 22 in such relation to the necks l6 of the slots that they cannot be removed.

So long as the handles 2| remain in the vertical position, the assemblage above described constitutes a rigid, self-sustaining structure. However, the handles 2| may he accidentally moved by being bumped etc. to the horizontal position thus releasing the braces. In order to overcome this undesirable feature a locking member 23 is slidably mounted in a slot 24 in the handle 21 of the rotatable locking collar. One end 25 of the locking member is divided and the portions so formed turned outwardly from the body thereof in the form of wings or stops 26. 1 The other end 21 is notched to form a single projecting wing 28 turned outwardly from the body thereof. These outwardly turned wings 26'and 28 prevent the locking member from falling out of theslot 24. The single wing 28 permits the use of two such looking members on adjacent handles where the space is limited by reason of onebein'g able to overlie th other in the manner shown in Figure 3. When the locking member is in the position shown in chain lines on Figure 4 the handle 2| can be freely moved to insert or release the braces. When the locking member is moved inwardly beneath the gusset plate (solid lines, Figure 4) then the handle cannot be moved to the horizontal position since the locking member strikes the bottom of the gusset plate preventing movement of the handle.

While there has been 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.

We claim:

1. In a separable connection for securing diagonal braces to the rectangular end frames of a knockdown scafiold having at least one gusset plate on the end frame, each having a keyhole slot therein including an eye and a restricted neck, a collar rotatably mounted on each end of the braces, said collar having a portion shaped 4 and dimensioned to enter said neck when turned to one position and be held against removal when turned to another position, retaining means integral with the brace on either side of the collar whereby the collar is maintained against axial or longitudinal movement, and handle means on the collar for rotation thereof, the combination with said separable connection of a pin mounted in an opening in the handle means for movement transverse to the plane of rotation of said collar whereby rotation of said handle is prevented when said pin is in one extreme position and freely rotatable when the pin is in the other extreme positiomsaid pin being slotted at one end and bent outwardly in opposite directions from the plane of the body of the pin preventing removal from the opening in the handle at said end, the opposite end having a notched portion and an outturned portion whereby the pin is removable at said end by turning the pin into a plane parallel to the plane of rotation of the collar.

2. In a separable connection as claimed in claim 1 having a pair of gusset plates in each corner of the frame and a pin slidably mounted in the handle of each collar, said notched portion of one pin being arranged to receive the outturned portion of the adjacent pin whereby each collar is locked against rotation.

CLAIR F. MARONEY. DANIEL I. WEISZ. RALPH W. MCGREW.

References Cited in the file of this patent UNITED STATES PATENTS Niunber Name Date 1,386,671 Zych Aug. 9, 1921 1,992,683 Webb et a1. Feb. 26, 1935 2,483,862 Weisz Oct. 4, 1949

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