Patent GB-528853-A (GB)
Title: Improvements in releasing and locking mechanisms for driving shafts, particularly adapted for value stamping machines
IPC: B41K3/64
Filed: 1939-05-06
Abstract: 528,853. Postmarking-machines. BUGGE, Y. May 6, 1939, No. 13564. Convention date, May 7, 1938. [Class 100 (ii)] Stopping and starting arrangements.-In a releasing and locking mechanism for driving shafts particularly for value stamping machines wherein the working motion of the shaft comprises a certain angle of rotation (usually a complete revolution) and wherein the shaft in each zero position is locked and released for starting by an exterior impulse upon a feeler which co-operates with a releasing member cooperating with a rotating locking member connected to the driving shaft, the feeler is suspended on the rotating locking member. Abutments 7, 10 on the releasing member 4, Fig. 1, engage abutments 8, 11 formed by the rim of the locking member 2. Feeler arm 12 is pivoted eccentrically or otherwise at 17 to locking member 2 and has a feeler 13 pivoted to it at 14 (for clockwise rotation only) which is acted on by a letter to be stamped moving from left to right along line 15 to move releasing member 4 to the right. Locking member 2 is thereby released and commences to rotate, due to manual or power driven force on driving shaft 1, carrying round with it arm 12 which is bent at a to engage cut away edge b of member 2 so that feeler 13 drops down on the letter in the position shown in dash and dot lines near the end of the revolution. At this point rib 22 engages projection 7 to drive releasing member 4 into the locking position and abutment 21.is engaged by feeler 13 to prevent further release of member 4 until the letter has passed. Abutment 24 engages projection 7 and prevents abutment 11 fouling portion c of member 4 after half a revolution ; projection 25 on member 4 serves a similar purpose. Abutment 24 may be continued all round the periphery of locking member 2 so as to positively guide member 4. The angle of operation of driving shaft 1 can be decreased by providing two or more feeler arms 12 to operate successively. Gearing may be interposed between shaft 1 and member 2 to alter the angle of operation. Member 4 may operate a switch to start and stop a driving motor and may be provided with a notch 28 to receive a member for blocking the mechanism and an abutment 29 for engagement with a locking key. In a second construction, Fig. 4, a member 34 integral with locking member 2 engages releasing member 31 which is restrained by cam surface 37 of member 30 secured to feeler arm 12. Displacement of feeler 13 allows member 34 to raise member 31 by interaction of inclined surfaces 35<SP>1</SP>, 36<SP>1</SP>, Fig 7, and pass underneath it. In the stationary position, surfaces 35, 36, 1 millimetre in length, of members 34, 31 are in contact and one or both of these is perpendicular to the direction of motion of 34 at commencement of rotation, and a spring 39 or weight urges member 31 upwards into releasing position. Arm 30 is restrained against the impulse action on the feeler by a weak spring 43. Cam surface 37 is long enough to maintain member 31 in a stationary position until feeler 13 has made a certain rotation and is rounded so that it slides above member 31 at the end of the revolution.