Patent GB-963914-A (GB)
Title: Blast machine enclosure
IPC: B23Q11/00
Filed: 1961-11-06
Abstract: 963,914. Blasting. BELL INTERCONTINENTAL CORPORATION. Nov. 6, 1961 [Nov. 29, 1960], No. 39602/61. Heading B3D. A centrifugal blasting machine includes a frame, a closing plate and access door assembly movably mounted on the frame, the closing plate being in the form of a rigid, flat plate and being movable in a rectilinear path relative to the frame, and the door being also movable in a rectilinear path relative to the frame with the two paths intersecting. A centrifugal blasting machine having means for throwing abrasives on to the surfaces of articles tumbled in the barrel portion of a conveyer chain 13 has a door 10 and a closing plate 11 co-operable therewith. The door 10 includes an outer panel having upper and lower portions 16, 17, the lower panel portion 17 having a lip 18 forming, in conjunction with the lower edge of the upper panel portion 16, a slot 20 for the entrance of air into the blasting chamber. A deflector plate 21 is secured to the door and provides a channel for the incoming air directing it downwardly to impinge against the angled lower edge portion 23 of the lower panel portion 17. The upper and side edges of the door are framed by angle members 24, 25 and the lower edge of the door is framed by a flat strip 26. Journalled between the side angle members 25 is a pivot shaft 28, one end of which projects beyond one of angle members 25 and has secured thereto an arm 29 to which is attached a tension spring 30 anchored to a bracket 32<SP>1</SP> rigid with the door. Removably mounted on the shaft 28 is a baffle plate 32 provided with vertical and horizontal reinforcing members 33, 34. When the door 10 is closed the lower edge of the baffle 32 clears the conveyer chain 13 by only a very slight amount so as to prevent small articles becoming wedged between the conveyer chain and the door 10 or the closing plate 11. A bracket 36 fixed to one of the angle members 25 carries a adjustable screw 37 co-operating with the arm 29 to determine the position of the baffle 32. A channel member 41 secured between the upper edges of the side angle members is provided with a sealing strip 42 which engages a frame portion 43 of the machine when the door is closed. The mechanism for opening and closing the door includes flexible elements such as the cable 44 attached to the channel member 41. The latter carries at its ends rollers 47 operating in guide channels 48. The door has a plate 50 extending outwardly beyond the side angle members 25 and provided with angle members 51 located between angle members 52, 53 rigid with the frame of the machine. The edges of the plate 50 have wear strips 56. A portion of the plate 50 extends in overlapping relationship to the upper panel portion 16, the lower edge 58 of this portion terminating closely adjacent to the baffle 32. The interior of the plate 50 is preferably lined with resilient material 59 the lower edge 60 of which projects beyond the confines of the door for contacting engagement with the closing plate 11. The closing plate 11 consists of a flat rigid plate 65 reinforced by an element 66 which engages a portion 67 of the machine frame to act as a stop when the plate is in lowered position. The opposite side edges of the plate 65 carry angle members 70 and wear strips 71 located within angle members 73, 74 secured to the machine frame. The plate 65 is moved to open and closed position by a piston and cylinder motor 90, the piston-rod 91 being connected to an arm 93 rigid with the plate 65. To prevent binding of the plate 65, the latter is secured by brackets 86 to chains 81 trained over sprockets 80 at the opposite ends of a shaft 78 mounted in the machine frame portion 67 and over sprockets 84 at the opposite ends of a shaft 82 mounted in the side standards 83 of the machine. The baffle 32 and plate 65 may be of manganese steel. To open the machine, the door 10 is first raised and the closing plate 11 is then lowered. To close the machine, the closing plate 11 is first raised and the door 10 is then lowered. In a modification, Fig. 9, the closing plate 100 is moved by cables 120, 122 wrapped round drums 116, 118 and having their ends secured to the upper and lower edges of the closing plate. The drums 116, 118 are fixed on a shaft 110 mounted by brackets 106, 108 on a frame member 104 and rotated by a motor 114 through reduction gearing 112. In a further modification, Fig. 11, the closing plate 130 is moved by a piston and cylinder device, and is guided by a bar 146 secured thereto and sliding between vertical guide plates 148, 148 mounted on cross supports 150, 150. Specifications 865,216 and 865,217 are referred to.