Patent GB-943425-A (GB)
Title: Apparatus for making impressed markings on elongated travelling workpieces
IPC: B29C59/04
Filed: 1961-01-20
Abstract: 943,425. Embossing. SCHUMAG SCHUMACHER METALLWERKE G.m.b.H. Jan. 20, 1961 [March 31, 1960], No. 2426/61. Headings B6C and B6J. [Also in Division B3] Apparatus for forming impressions at given intervals on elongated travelling workpieces is characterized in that at least one die holder adapted to carry an embossing die is mounted for rotation on a shaft, there being driving elements on the shaft and die holder for transmitting rotation of the shaft to the die holder while allowing the die holder to rotate in advance of the shaft, and drive means are provided for rotating said shaft so as to impart to the die holder a peripheral speed which is less than the speed of the workpiece by an amount which is equal to the possible degree of slip between the die and the workpiece, said driving elements being arranged to allow the die holder to accept the speed of the workpiece when the die contacts the workpiece, there being catch means for retaining the driving element of the die holder, after the latter has left the region in which its die contacts the workpiece, until the driving element of the shaft has caught up with it the driving element of the shaft being arranged then to release the catch means to permit the die holder to be rotated by the shaft at the speed thereof. In an embodiment embossing dies 3 and 4, Fig. 4, are carried by segments 1 and 2 respectively loosely mounted on shaft 5 and 6. When the shafts are rotated abutments 9 and 10 on entraining members 7 and 8 keyed to the shafts 5 and 6 engage and deflect downwardly spring-loaded yielding levers 11 and 12. The machine is driven independently of the workpieces by a drive shaft 13 rotated by the press tool which delivers the workpieces. The drive shaft rotates the shaft 5 through sprocket and chain gearing and the shaft 6 through gearing 15, 16 and 17. A rocking lever 18 pivotally mounted on the shaft 5 is oscillated by an eccentric 19 connected with the intermediate gear 16 and said lever operates a spring-loaded push rod 20. A carrier slide 21 is adjustably mounted on the machine frame to enable the embossing dies to be spaced the required distance from backing rollers 26 and 27. In operation, the drive means directly imparts rotation to the two segments 1 and 2. The die embosses the workpiece on each full revolution of the segment 1 but owing to the action of the eccentric 19 the die 4 only forms an impression when the eccentric pushes the die 4 on to the workpiece e.g. every third revolution of the segment 2 if the transmission ratio between the intermediate gear 16 and the segment is 1: 3. Thus a series of two different unequally spaced impressions are formed on the travelling workpiece. In order to ensure a satisfactory impression when slippage occurs, and especially when longer legends are impressed on to the work, allowance for slippage is made by suitably selecting the speed of rotation of the segments. When the workpiece travels at a slightly higher speed than the peripheral speed of the driven segments and the impression begins to be formed the fixed abutments 29, 30 on the segments slightly gains on the abutments 9, 10 of the entraining members 7, 8 because the segments 1, 2 are carried around at the speed of the workpiece. Thus each segment and its die accepts the increased speed of the work due to slippage. After the impression has been made, the fixed abutments 29 and 30 continue to lead the entraining abutments until they reach projections 32 and 33 on levers 11 and 12 where they are intercepted until abutments 9 and 10 have caught up and, by depressing the two levers 11 and 12, release the abutments 29 and 30 and hence the segments for further entrainment by abutments 9 and 10.