GB380093A - Improvements in and connected with apparatus for riveting metal tubular members - Google Patents

Abstract

380,093. Riveting. VICKERS (AVIATION), Ltd. and WALLIS, B. N., Weybridge Works, Byfleet Road, Weybridge, Surrey. June 9, 1931, No. 20620. Divided on 380,091. [Class 83 (iv).] In making tubular members formed from bent metal strips, particularly for use as aeroplane spars, rivets are inserted by hand from outside into holes located along opposing seams in the tube and are riveted by an expanding riveter located inside the tube in conjunction with oppositely arranged dollies, the tube being supported on a carrier which is moved intermittently to present the rivets in succession to the riveter and the latter being actuated by fluid pressure in timed relation with the carrier. The machine bed comprises channel members 11 supported on legs 12 and the carrier 15 is mounted on pairs of rollers 14 carried by transverse shafts 13 and is guided by inclined rollers 16. The tube 17 is held at one end by a collar 18, Figs. 1 and 4, having opposed holes 19 registering with holes in the tube seams and adapted to receive screwed pins 22 which lie in vertical slots 23 in brackets 24 on the carrier and are secured by spring catches 25, and is supported at the other end by a screw jack 27 on the carrier. The rivets are inserted by hand into the previously drilled seams and are prevented from falling out by bars 28 lying against their heads and supported by arms 29 pivoted to the machine frame. Screws 32 prevent the bars from falling inwards when the finished tube is removed. The internal riveter 40 is supported by a stationary tube 65 and comprises pivoted arms 41, Fig. 8, normally held contracted by a spring 44 and arms 43 and having heads 42 which are expanded against the rivets by a conical plunger 48 operated by a hydraulic cylinder 45 and withdrawn by a spring 47. Fluid is supplied to the cylinder 45 from a control box 63, Fig. 7, through a conduit 64 and the tube 65, the box being operated by two cams 55, 56 on a shaft 39 rotated by hand. A rise 61 on the cam 56 depresses a plunger 62 through a rocking lever 57 to admit fluid to the cylinder 45 for a short time and the circular periphery of the cam 55 normally maintains a plunger 67 depressed to exhaust the cylinder a flat portion 66 on the cam 55 allowing the cam 56 to operate. The cams 55, 56 may be replaced by a single cam. The rivet heads are supported during riveting by dollies 49, Fig. 6, carried by arms 50 pivoted at 51 to the machine frame and normally held apart to allow axial feeding of the tube 17 by means of a spring 52. A cam 54 on the shaft 39 engages between rollers 53 on the arms 50 to position the dollies during riveting. Spacing apparatus.-A rack 33 is attached to the carrier 15 and is held stationary during riveting by a pawl 37, Figs. 5 and 7, on an arm 69 secured to a shaft 71. When the riveter 40 has contracted and the dollies 49 have withdrawn a cam surface 74 on the cam 54 engages a roller 73 attached to the arm 69 and moves the pawl 37 transversely, releasing the rack and allowing a weight attached to a pulley 34 to draw the carriage forward a distance equal to half the pitch of the rack teeth, a second pawl 68 on the arm 69 then engaging the tooth which the pawl 37 has left. On passing off the cam 74, the roller 73 is released and a spring 77 returns the pawl 37 into engagement with the next tooth of the rack, the weight having moved the rack through another half pitch distance. The arm 69 is maintained by a spring 79 in contact with a plate 80 capable of transverse movement by a disc 86 attached to a shaft 83 screwing in a hole 85 in the member 11. Inclined slots 81 in the plate 80 engage the heads of stationary bolts 82 so that on rotation of the shaft 83 by a hand wheel 78 the plate will be moved forwardly or rearwardly to locate the work in the exact position for the rivets to be operated upon. Should it be desired to advance the work through one or more pitch distances without actuating the riveter, a handle 110, pivoted at 111, may be reciprocated to give the arm 69 one or more spacing motions through a collar 171 on the shaft 71 engaging a cam end 113 on the lever. A spring 112 returns the lever. At the end of its traverse the carrier 15 engages a block 97, Fig. 1, secured by bolts to a second block 97 attached to the machine frame, rubber blocks 100 being mounted between the blocks 97. Operation.-Rotation of a hand-wheel 38 on the shaft 39 actuates the riveter 40 and the dollies 49 and moves the work forwards, step by step. The work is held together while being inserted in the machine by a few widely separated rivets whose heads are further acted upon by the riveter in their passage through the machine. Actuation of the machine is prevented by a plunger 91, Fig. 6, forced into engagement with a groove 90 in the hand-wheel 38 by a spring 92 until the plunger is withdrawn by a pedal 96 acting through a link 95 and lever 93, and rotation of the hand-wheel is confined to one direction only by a pawl 89 engaging a ratchet 88 on the wheel. To maintain the inner surface of the tube truly cylindrical the constituent strips may be lapped and joggled and the strips may be drilled by the machine described in Specification 380,091.