Patent GB-291272-A (GB)
Title: Improvements in an automatic can testing machine
IPC: G01M3/32
Filed: 1927-09-24
Abstract: 291,272. Potts, H. E., (Continental Can Co., Inc.). Sept. 24, 1927. Testing efficiency of cans.-The cans to be tested are placed under air pressure, the air escaping through a leak operating means for automatically separating such can from the sound cans by reason of the pressure of such air leakage against a non-compressible fluid surrounding the leaky can. General arrangement. A turret 13, Fig. 1, provided with a series of test units 14 is carried by a sleeve 3 rotated about a pillar 4 through a clutch 7 and gearing driven from a motor 12. Test unit. Fixed to the turret is a cup-shaped receptacle 15, Figs. 1, 3 open at the upper end. The receptacle is provided with a supporting plate 16 having a curved plate 17 for centering a can. Above the plate is a head 18 carrying a rubber pad 19 adapted to close both the can and the chamber 15. In connection with each unit are two rods 21 carrying upper and lower cross heads 22, 26, the lower one carrying a roller 29 engaging in a cam groove 31 in a fixed circular bracket 30. The cam thus raises and lowers the rods 21 and cross heads. The plate 16 is carried by a rod 32 extending in a fluid-tight manner through the chamber 15 and the turret and provided with a head 34 bearing against a roller 38 carried on a rock arm 36 pivoted to the lower cross-head. When the cross-heads occupy their highest positions, a roller 39 on the arm 36 lies in a recess 40 in a fixture 41. Air supply. Compressed air is supplied through the centre of the closing pad 19. The sleeve carrying the plate 18 carries a valve head 44, Fig. 17 having a main port 48 closed by a spring- pressed valve 49, and a small bye-pass 54. A stationary cam engages the head 52 to open the valve which closes when released bv the cam. The flexible supply pipes 46 are connected to a rotating head 55 connected by a pivoted link 57 to the upper cross-head. A supply pipe 63 leads to the rotating head which is provided with distributing ports 61. Incompressible-fluid supply. The chamber 15 of each unit is supplied with water from a supply pipe. Near the upper end of the chamber is a passage 65, Fig. 9, connected to a pipe 66 leading down into the chamber. The passage 65 leads to a control valve 68. The valve includes a movable inner sleeve 71 and a fixed outer sleeve 69. The sleeve 71 is provided with a cap 72 of insulating material in which is mounted a screw terminal 73. The valve is rotated bv the slots 75 in a disc 74 engaging fixed pins 78 on a ring 77 as the turret rotates. Curved portions of the disc between the slots retain the valve in the position it has been moved into by a pin 78. The valve has a central passage 79 and two radial passages 80, 80, Fig. 11, connected by a circular passage 81 which at certain positions of the valve connects with the passage 65. In line with the passage 79 and in the upper part of the sleeve 71 is a chamber 82 connected with a small chamber 84 into which the screw 73 dips without contact. Two radial passages 85, 86 are also provided. Operation. The cans are fed along a runway 87, Fig. 2, by a belt 88 and into the machine at the station A by a rotating pocket wheel 90 cooperating with a guide 93. As the turret rotates, the cam groove lowers the plate 18 to close a can, the support 16 being delayed slightly by the movement of the rock arm 36 so that the pad 19 firmly closes the can. Next the head 52 is engaged by its cam and the air supply opened. The can is lowered into the chamber 15 and the latter closed -after release of the air valve 49. The water rises around the can and overflows through passages 65, 79. Station B is reached with the passage 65 still open to the atmosphere. When the station C is reached, the valve is moved another step, the passage 65 is cut off from passage 79 and aligned with the passage 85. If a leak exists in the can, the water rises in the chamber 82 until the chamber 84 is filled. Overflow of the chamber 84 leaks away through an opening provided. The valve is moved another step before the station D is reached, and the chamber 82 is cut off from the chamber 15, the liquid being trapped in the chamber 84. The cam 31 next raises the cross-heads so that the can is at the top of the chamber 15, and on passing under a contact plate 101 the circuit of a solenoid 100 is made if the contact 73 is " live " owing to the presence of water in the chamber 84 due to a leaky can, and the solenoid causes an arm 95 to be moved and to eject the leaky can into a shoot 96. If no leak exists, the solenoid is not energized and the can passes on to be ejected by a spring arm 102 into the shoot 103.