| 摘要 |
<p>1,022,174. Stapling machine. SIGNODE CORPORATION. Nov. 6, 1962 [Nov. 15, 1961], No. 41997/62. Heading B4C. [Also in Division F2] A driving tool for fasteners, such as staples or nails, comprises a piston-and-cylinder assembly 7, 8, driver means 9 secured to one side of the piston, diaphragm valve means 14 for controlling the flow of fluid under pressure to the cylinder, second valve means 29 for controlling the operation of the diaphragm valve means, and actuating means 32 for positioning the second valve means to effect opening and then closing movement of the diaphragm valve means. The diaphragm 14 in its normal position is urged by a spring into contact with the upper edge 7a of the cylinder 7. The second valve 29 comprises a ball mounted in a sleeve which is secured in a handle 2 constituting part of the tool housing 1; the ball valve controls the flow of compressed air from a chamber 3 to a chamber 22 via a passage 24 and the exhaust from the chamber 22. In operation, compressed air is fed into the chamber 3 via a pipe 4 and passes through valve 29 and passage 24 into chamber 22 to thereby, together with spring 19, force the diaphragm into contact with the edge of the cylinder. Upon lifting a trigger 33 a pawl 37 thereon contacts a plunger 31 which lifts the ball 29 off a seat 27 and presses it against a seat 26 thereby exhausting the chamber 22. Compressed air in a chamber 17, which is in communication with the chamber 3, then lifts the diaphragm away from the edge of the cylinder 7 and acts on the piston 8 to drive it downwardly and so eject a staple 12. Continued upward of the trigger causes the pawl to slip off the end of the plunger 31 and so allow the ball to re-engage the seat 27, thereby again admitting air into the chamber 22. The diaphragm is then urged into contact with the end of the cylinder and prevents the entry therein of compressed air. The piston is returned to its initial position by means of air in the chamber 3 acting on the inner side 8a of the piston via ports 54 in the cylinder wall. The air is exhausted from the cylinder via a passage 51 and a chamber 52. In the modification shown in Fig. 8, the air is exhausted from the cylinder 7 on the return stroke of the piston by means of a passage formed in a spindle member 146 secured to the diaphragm, the air escaping through a port 144 in a cap 141. In this modification the second valve is in the form of a conical closure member 112 arranged to contact a seat 109 in a sleeve 112, a ball-operated catch device 129, 132 being provided in place of the pawl 37. The staples are mounted on a guide bar 71 and urged toward the driver 9 by means of a pusher 72 under the action of a spring. A spring clip 86, Fig. 6 (not shown), is arranged to extend over the full length of the charged magazine in order to prevent the staples from coming off the guide bar during operation.</p> |
