GB Patent: GB-649,582
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Improvements in, or Relating to, Presses
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Patentee:
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John Eaton (exact or similar names) - unknown, England |
Manufacturer: |
Not known to have been produced |
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Patent Dates:
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Applied: |
Nov. 05, 1947 |
Granted: |
Jan. 31, 1951 |
Espacenet patent
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Joel Havens "Vintage Machinery" entry for Whatton & Sons, Ltd.
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Description: |
A pneumatic press comprises a toolcarrying reciprocable ram 1 which is driven towards a fixed bed 6 in two stages, namely, an initial stage under the control of a low-pressure cylinder 16 to bring the tool into contact with, or proximity to, the work and a working stage under the control of a high-pressure cylinder 14 which perates the ram through a rigid lever 24 which, durng the initial stage is disconnected from the ram but is so displaced that, as the ram completes its initial stage, it makes positive drivng connection with the ram.; The cylinder 16 and a power lever 12 are pivoted on a fixed bracket 22 and the low pressure piston 18 is coupled to a cam 23 pivoted near one end of the lever 12 and is adapted to engage a stop 28 on the beam 3 only when the ram 1 is driven through its initial stage. The lever 24 is spring-urged into engagement with the stop 28 which limits the movement of the cam 23. A relay valve 19 is operated by a spring-loaded arm 29 and a rod 30 which has a projection 32 normally retained in the path of the lever 24. Compressed air is supplied to the press through pipes 35, 36, and hence to a valve 37 controlled by a spring-returned pedal 38 and an automatic valve 40, respectively.; On depressing the pedal compressed air flows from the pipe 35 through pipes 41. 42 to the inlet of the relay valve 19 and through a branch pipe 43, pressure reducing valve 44 and a safety valve 45 to the cylinder 16 being exhausted through pipes 51, 49. The piston 18 displaces the cam 23 angularly away from the lever 24 allowing it to engage the stop 28. As the upper part of the cam engages the stop 28 it urges the beam upwards until a shoulder 27 on the lever 24 is spring-urged under the stop 28 and hence actuates the valve 19. Compressed air now flows through a pipe 46 and the valve 40 to the cylinder 14 to actuate the lever 12; air being exhausted from the top of the cylnder through a pipe 50.; On releasing the pedal 38 the underside of the cylinder 16 and the relay valve 19 are exhausted whilst pressure is supplied to the automatic valve 40 and the pressure in the pipe 36 diverted to the power cylinder 14. Simultaneously, compressed air flows through the pipe 51 to the upper end of the cylinder 16 whereupon a reverse movement is imparted to the cam 23 which in turn displaces the lever 24 and hence permits the valve 19 to revert to its original position and raise the cam 1. |
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