GB1218001A - Apparatus for fabricating wood structures - Google Patents

Abstract

1,218,001. Attaching spiked plates. HYDRO AIR ENG. Inc. 6 Jan., 1969 [8 Jan., 1968], No. 819/69. Heading B4C. Apparatus for pushing spiked plates N1, N2 into wooden truss joints comprises a press 9 having an upper jaw 27 on a bracket 25 joined to a fluid cylinder 31 and a lower jaw 33 forming part of the piston of the cylinder 31, the press being floatingly mounted on a carriage 47 comprising rails 49 and having rollers 53 engaged in fixed rails 23 for horizontal reciprocation by a fluid cylinder 57 having its piston rod connected to the carriage 47 by brackets 67, 71. The timber T constituting the truss is clamped to rails 39 and the lower nail plate N1 rests on a tray 43. In one embodiment the press 9 is connected to the carriage 47 by a spring suspension means 45, the cylinder 31 and hence the upper jaw 27 resting, via a bracket 55 on springs 73, 77 separated by a washer 93, and the lower jaw being partially supported with the cylinder 31 by the springs 73, 77 and partially supported on the upper end of a tube 85, which has a washer 89, Fig. 6 (not shown), abutting the spring 77 at its lower end, the other end being held on the rail 49 of the carriage 47. A rod 79 extends through the tube 85 and is fixed to the lower jaw at its upper end and has a washer 84 supporting a further spring 75 and adjusting nuts 83 at its lower end. Fluid entering the lower part of the cylinder 31 initially causes the cylinder and upper jaw 27 to move downwards compressing springs 73, 77 until the washer 93 is acted on by the spring 75, then equal forces act on each jaw which converge at the same rate. If one side of the wood of the truss T is harder than the other then the jaw will be stopped on the harder side and will continue on the other until the forces on each jaw are again equal. The suspension arra ngement 45 can be rotated about rollers 53, orthe springs on one side can be compressed more than on the other to compensate for warping of the wood. In a second embodiment the spring arrangement is replaced by a pneumatic compensating arrangement 101, Fig. 9, comprising an expansible chamber 103 having a diaphragm (107), see Fig. 11 (not shown), joined by a rod 109 and pivot 111 to the bracket 25, the chamber 103 being itself joined to the carriage 47 by a bracket 115 and rods 117 passing through cylindrical guides 123 attached to the bracket 25. The chamber 103 is supplied with compressed air below the diaphragm and can be relieved through a line 131 by a valve 133, controlled by a button 141 operated by the upward movement of a bolt 137 joined to the lower jaw 33 by a bracket 135, so that upward movement of the lower jaw 33 permits downward movement of the upper jaw 27. The compressed air supply may be the same as that used for the cylinder 57. The apparatus may have castors 18, Fig. 3, for movement on rails 19 and may be locked in position by a clamp 21 or it may be moved on an air cushion contained in a dome-shaped chamber 165, Fig. 9, and may be held at any position by a suction cap 171 connected to a vacuum pump.