US3867881A

US3867881A - Method and apparatus for printing on workpieces with an outer surface having the form of a truncated cone

Info

Publication number: US3867881A
Application number: US368255A
Authority: US
Inventors: Kurt Blattner
Original assignee: Madag Maschinen und Apparatebau Dietikon AG
Current assignee: Madag Maschinen und Apparatebau Dietikon AG
Priority date: 1972-06-14
Filing date: 1973-06-08
Publication date: 1975-02-25
Anticipated expiration: 1992-02-25
Also published as: CH566211A5; DE2328747A1; GB1413701A; DE2328747B2

Abstract

Method and apparatus for printing on the surface of a noncylindrical workpiece moving against a printing block with a printing tape therebetween in which both an angular and a straight line motion is imparted to the tape.

Description

United States Patent [191 Blattner [451 Feb. 25, 1975 METHOD AND APPARATUS FOR PRINTING ON WORKPIECES WITH AN OUTER SURFACE HAVING THE FORM OF A TRUNCATED CONE [75] Inventor: Kurt Blattner, Dietikon, Switzerland [73] Assignee: MADAG Maschinenund Apparatebau Dietikon AG, Dietikon, Switzerland [22] Filed: June 8, 1973 [21] Appl. No.: 368,255

[30] Foreign Application Priority Data June 14, 1972 Switzerland 8861/72 [52] U.S. Cl ..101/7,101/32, 101/38 R, 101/426, 156/234, 156/540, 197/151 [51] Int. Cl B411 17/28 [58] Field of Search 101/7, 5, 38 A, 40, 38 R, 101/39, 426; 156/234, 540; 197/151, 158

[56] References Cited UNITED STATES PATENTS 153,962 8/1874 Jennings 101/38 R 2,288,298 6/1942 Norman et all 101/38 A X 1 3,309,256 3/1967 Warsager 3,613,857 10/1971 Thevis et al. 197/158 X FOREIGN PATENTS OR APPLICATIONS 613,023 11/1948 Great Britain .1 101/39 1,097,507 1/1968 Great Britain 101/38 R Primary Examiner-Clifford D. Crowder Attorney, Agent, or FirmDarby & Darby [57] ABSTRACT Method and apparatus for printing on the surface of a non-cylindrical workpiece moving against a printing block with a printing tape therebetween in which both an angular and a straight line motion is imparted to the tape.

10 Claims, 3 Drawing Figures 1 METHOD AND APPARATUS FOR PRINTING ON WORKPIECES WITH AN OUTER SURFACE HAVING THE FORM OF A TRUNCATED CONE The present invention concerns a method and apparatus for printing on workpieces whose outer surfaces are non-cylindrical, such as in the form of a truncated cone, by using an embossing band arranged between a block and the workpiece.

When printing on a workpiece whose outer surface has the form of a cylinder it has already been suggested, in order to permit a space-saving construction, to also design the printing block in the form of a cylinder and to press the workpiece, which is held loosely on a mandrel, for printing against the revolving block with the interposition of an embossing band. The rotary movement is transmitted by friction to the workpiece and the printing is effected without the lateral movement of the workpiece or block.

This general construction idea, namely to give the block and the workpiece a corresponding form to achieve the above mentioned advantages, can not be simply transposed in methods and devices for printing on workpieces whose outer surfaces are noncylindrical, such as in the form of a truncated cone, since the embossing band would be caused to move less rapidly in the range of the smaller diameter position than in the range of the larger diameter portions of the cone. This would lead to destruction of the embossing band.

In addition, the use of plane blocks which one had to utilize in view of the above mentioned difficulties at the expense of a space-blocking construction, had the additional disadvantage that the printing picture naturally had to be applied on this plane block in the shape of the development of the truncated cone of the workpiece. This made the production of the block much more difficult.

The present invention provides a method and an apparatus for printing on workpieces with a noncylindrical outer surface, such as one having the form of a truncated cone, which permits, on the one hand, a space-saving construction without relative movements between block and workpiece, as it is the case with the use of plane blocks, and which permits application of the printing picture in a simple manner on the block.

In the method according to the invention a printing block is used whose outer form corresponds to the workpiece. The block is rotated about its geometric axis and an angular pivoting movement about an imaginary axis extending perpendicularly to the surface of the block is imparted to the embossing band. The pivoting motion depends on the conicity of the workpiece in such a way that the center of the roll-off ring of the block on the embossing band coincides with the geometric apex of the truncated cone form of the block.

The device for carrying out this method in turn includes a pivot mechanism for the first arm of a parallel guide, the embossing band being so arranged on a second arm extending parallel to the first arm that its feeding direction is parallel to the second arm.

An embodiment of the device according to the invention is represented schematicallyin the drawing, which also shows an embodiment of the method according to the invention as well as a development process. In the drawings:

FIG. 1 is a schematic top view of an appratus according to the invention;

FIG. 2 shows the same view of a block and of the workpiece in the direction of the arrow A in FIG. 1; and

FIG. 3 is a representation of the development process.

In FIGS. 1 and 2 the printing block 1, having the printing information thereon, for example in the form of a die or engraving, is secured on a block carrier 2 and is revolved about its geometric axis. This block carrier is driven in the represented embodiment by two bevel gears 3 and 4, bevel gear 4 being connected to a pinion 5 which meshes with a rack 8 connected with a pushrod 6 of a hydraulic driving unit 7. As can be seen in FIG. 2, the workpiece 9 in the form of a hollow truncated cone is arranged below the block 1 and rotates loosely on a mandrel 10 so that the block and workpiece are in contact with each other along a directrix, with the interposition of an embossing band 11. The workpiece is pressed against the block I with the interposition of the embossing band 11, by means not shown here, so that when block 1 is set in rotation by the above-described driving unit 3-8,. the block and workpiece hob on one another and the printing picture is transmitted through band 11 to the workpiece.

The embossing band 11 is entrained by this hobbing movement between block 1 and workpiece 9 and is unwound from a supply roll 12 and wound on a roll 14 driven by a driving unit 13. Both rolls l2 and 14 are held each in a fork, or bracket 15. The forks are, on the one hand, connected with each other by a bar 25 offset from the center of the forks. Each fork is articulated, on the other hand, by a connection to one end of a re spective guide rod l6 each of whose other ends are connected to an additional guide rod 17. The forks l5 and the bars 25 form thus one arm of a parallelogram guide on which the rolls 12 and 14 as well as the embossing band 11 are held. The guide rods 16 and 17 form the other sides. A pinion 18 is connected with the guide rod 17 and meshes with a rack 20 having an extension 26. The extension 26 has a head 27 which is held and can move in a longitudinal groove 21 of a guide piece 19. The guide piece 19' rotates about a journal 22 rigidly connected with the pushrod 6 and is articulated at its end remote of the head 27 at pivot 24 by an adjusting device 23. This arrangement permits the angle between the geometric longitudinal axis of the guide piece 19 and the push-rod 6 to be adjusted.

If an axial movement in the direction of the arrow B in FIG. 1 is imparted to the pushrod 6 to drive the block, not only block 1 is set in revolution in the above described manner through

elements

8, 5, 4, 3, 2, but at the same time the guide piece 19 is entrained in the same direction. As guide piece 19 moves the head 27 is displaced in the longitudinal groove 21 toward the journal 22, that is, to the right in FIG. 1. This displacement is transmitted through a pivoting mechanism, including a guide piece 19, rack 20 and pinion 18, to the guide rod 17 and thus to the forks l5 and the embossing band 11. The amount and the direction of the angular pivoting movement is determined by the position of the fulcrum 24 of the adjusting device 23 relative to the pushrod 6. If the fulcrum is displaced into a plane passing through the pushrod 6, an angular pivot movement can be prevented completely in which case the apparatus can be used for printing on workpieces with an outer surface in the form of a cylinder. If the fulcrum 24 is displaced to the left of push rod 6, with regard to the drawing, the embossing band 11 is pivoted in the opposite direction.

As far as the method of operation is concerned, the center of the hobbing surface 33 of the truncated block 1 must lie on the embossing band 11 along a line 29 projected from the (imaginary) apex X of the truncated cone. It is possible, and for certain applications even expedient, to form the

parallelogram

15, 16, 17, 25 by a suitable selection of the lengths of the guide rods 16. However, such an arrangement has a disadvantage in that the lengths of the guide rods 16 must always be changed when embossing workpieces of different conicity. In order to avoid this disadvantage, the arrangement is such that the embossing band 11 and the rolls l2 and 14 respectively, as well as the forks 15 are turned about the intersection Y of the center line 28 of the embossing band with the contact line 29 between block 1 and the embossing band 11. In this arrangement the length of the guide rods need not be changed, regardless of the conicity of the workpiece or of the block.

In order to achieve that the development lies on annular ring segment 33 (also shown by

lines

30 and 31 in FIG. 1) with the center in X, despite the fact that the angular pivoting movement takes place not about X but about Y, an axial advance movement is imparted to the embossing band additionally by the motor 13. The movement of the embossing band 11 is thus a combined movement and it is composed, on the one hand, of a pivoting movement about the center Y, and on the other hand, of an axial advance movement.

The combined movement is represented in the diagram in FIG. 3, divided into the two partial movements. Starting from an assumed neutral position, in which the contact line between the block and the embossing band corresponds to the line C Y D, the advance movement takes place first in the direction of the center line 28 of the embossing band by which the points C, Y and D are transported to Cl, Y1 and D1. The points C1 and D1 are outside the

boundary lines

31 and 30 of the roll off surface 33. If a pivot movement about the center Y1 follows, the said points C and D move to C2 and D2, the pivot angle being given by the conicity of the workpiece and of the block and corresponding to that transmitted within the respective time interval over the guide piece 19, head 27, extension 26, rack and pinion 18 to the parallelogram l6, 17, 25.

By the following advance movement, which is perpendicular to the line C2, D2, the points move to C3, Y3, D3 which lie again on the boundary lines and 31 and on the center line 32 respectively, of the roll-off annular ring section surface 33.

The two partial movements, that is, the pivot movement and the advance movement take place steadily and simultaneously, so that it is possible, despite a pivoting of the embossing band 11 about Y instead of X, to achieve a roll-off movement about the center X. It is obvious and irrelevant for the explanation of the combined angular pivot advance movement, that the same result is obtained if the angular pivot movement takes place first, followed by the advance movement.

The above described arrangement can naturally also be used for printing on cylindrical workpieces, in which case the center line of the embossing band is set perpendicular to the cylinder axis and the transmission of a pivot movement is foregone, for example, by disengaging the connection between the guide piece 19 and the head 27.

Furthermore, conical workpieces can also be embossed where the apices of the cone lie on the driving side of the block, in which case the pivoting of the embossing band takes place in the opposite direction.

This way it is possible to provide a device for printing on workpieces with an outer surface in the form of a truncated cone, which can be produced in a spacesaving manner and which also has the advantage that the blocks can be produced in a simple manner.

What is claimed is:

1. A method for printing on an object having a conical outer surface comprising the steps of providing an object having a conical outer surface, providing a printing block having a corresponding conical outer surface, providing an elongated printing tape, rotating one of said object and said printing block about its geometric axis in driving engagement with the other with the printing tape engaged therebetween to move said printing tape in a first direction parallel to its length, and imparting a pivoting movement to said printing tape in a direction at an angle to said first direction about an imaginary axis perpendicular to its surface passing through the printing block.

2. The method of claim 1 wherein the center of an annular ring travelled by the block on the printing tape due to the two movements imparted to the tape coincides with the geometric axis of the block.

3. A method as in claim 1 wherein said axis passes through the intersection of a line parallel to the longitudinal axis of the tape and the contact line between the block and the tape.

4. Apparatus for printing on a workpiece having a non-cylindrical outer surface comprising a printing block having an outer surface of substantially the same shape as the workpiece to be printed, an elongated printing tape, means for revolving one of said printing block and workpiece in driving engagement with the other with the tape therebetween to impart movement to said tape in a first direction parallel to its longitudinal axis, and means for pivoting said tape in a direction at an angle to said first direction about an imaginary axis perpendicular to the tape surface passing through the printing block.

5. Apparatus as in claim 4 wherein said revolving means comprises means for revolving said block about its geometric axis.

6. Apparatus as in claim 4 wherein both said printing block and said workpiece are of conical shape and contact is made with said tape by said block and said workpiece over a sector of an annular ring during the revolving of said block and workpiece and the movement of said tape in said first direction, the center of the ring sector lying on a line corresponding to the geometric apex of the cone shaped block.

7. Apparatus as in claim 4 wherein said means for imparting the pivoting motion to said tape comprising an articulated parallelogram arm linkage, said tape being parallel to one of the arms of said linkage.

8. Apparatus as in claim 4 wherein said revolving means comprises means which are linked to the means for imparting a pivoting motion to the tape.

9. Apparatus as in claim 4 wherein each of said printing block and said workpiece are generally conical in shape and are located with the base ends adjacent one another.

10. Apparatus as in claim 4 further comprising means for controlling the angle of the pivoting motion imparted to said tape.