Take-off ring

Abstract

The invention relates to a take-off ring 10 which is provided in particular for use in connection with deep-draw presses 12. It serves for removing a top-shaped can body 11 from a drawing plunger 18. The take-off ring 10 includes a multitude of take-off elements 27 which are arranged uniformly distributed in circumferential direction U and separated in each case by a gap 48. The take-off elements 27 are interconnected by an annular base section 30 which extends around the take-off elements 27 in the circumferential direction U. Radially inwardly a spring section 38 and a transition section 39 of the take-off element follow. The transition section 39 is pivotable by way of the spring section 38 about a pivot axis 55 which extends in the circumferential direction U. A take-off tongue 35 extends in a transverse direction away from the transition section 39 toward a free end 41.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority of German Application No. 10 2010 019 322.4-14 filed May 3, 2010.

BACKGROUND OF THE INVENTION

The invention resides in a take-off ring which is suitable especially for use in an apparatus for the manufacture of can bodies, for example, in deep-draw presses. In such, apparatus can bodies for pressure containers or beverage cans are manufactured. The can body includes a can bottom and, extending therefrom a can wall which is manufactured from a blank of a single material without a seam or joint area. During this manufacturing process, the can body is disposed on a draw plunger. After the can bottom and the can wall have the desired shape, the can body must be removed from the draw plunger. This is the purpose of the take-off ring.

Such a take-off ring is known, for example, from DE 23 35 686. The take-off ring includes several take-off elements which are held together by an elastic means. This elastic means is formed by an elastic casting material. By way of the casting material, the take-off elements are interconnected by a surrounding ring and, in the end, form a design unit.

The manufacture of such a take-off ring is expensive: The take-off elements need to be set correctly aligned to a common radius. The elastic spring-like support is obtained by the elastic property of the casting material.

Take-off rings are also known from punching tools for punching or cutting metallic parts. They are used for the removal of punching waste, so-called punched out pieces, which after the punching procedure adhere to the punch and do not fall off, and which are retained by the slide-off arrangement in the piercing die bush when the punch is pulled out of the piercing die bush. In connection with this type of take-off arrangements however, it is not important whether during the slide-off procedure scratches or marks are left on the punched out pieces since they are considered waste material which is not needed anyway. A take-off arrangement for a piercing procedure is described in DE 10 2008 016 722 A1. There, at the front side of the punch a removing pin which is pre-tensioned by a spring is provided which, after the punching step pushes the punched out piece away from the plunger. The punched-out piece is retained by the take-off arrangement which includes radially inwardly projecting retaining hooks provided with a conical surface. During movement of the plunger, the punched out piece pushes the retainers radially outwardly as long as it slides along the conical area of the retainers as soon as the punched out piece is below the retainer they spring back radially inwardly and extend over in front of the punched out piece. With the subsequent retracting of the punch the punched out piece is released from the removing pin and falls downwardly through the cutting sleeve. The arrangement provides for a design of very long axial length.

In deep draw presses the take-off arrangements may be arranged not in the deep draw can for drawing the can body, but axially adjacent the deep draw can. It may therefore be considered to be an object of the invention to provide a take-off arrangement with which the additional stroke of the deep draw plunger required by the take-off arrangement is relatively small.

SUMMARY OF THE INVENTION

In accordance with the invention a take-off ring is provided which includes an annular base section. This base section extends radially inwardly by a spring section which defines a pivot axis extending in circumferential direction. Radially inwardly adjacent the spring section, there is a transition section which is pivotable about the pivot axis about in axial direction of the take-off ring. From the transition section a take-off tongue extends transverse to the radial direction and transverse to the circumferential direction of the take-off ring. The free end of the take-off tongue is radially and axially spaced from the pivot axis. The take-off elements are preferably arranged evenly distributed about the circumference. Upon sliding the can body through the take-off ring, the can body moves along the inner surfaces of the take-off tongues up to the free ends thereof whereby the take-off elements are pivoted about the circumferentially extending pivot axis. The free ends of the take-off tongues move as a result axially along the longitudinal axis of the take-off ring and, at the same time, radially outwardly. As soon as the can body has been moved fully through the slide off ring, the slide-off tongues spring back radially so as to abut the plunger. With the subsequent return movement of the draw plunger, the edge of the can wall abuts the free end of the take-off tongues and is moved off the draw plunger. This take-off ring is particularly suitable for use in connection with deep draw presses.

As a result of the arrangement of the spring sections radially outwardly around the take-off tongues an axially short design of the take-off rings can be achieved. The length of the take-off rings in axial direction is mostly determined by the length of the take-off tongues. The attachment of the take-off rings in axial extension of the deep draw can occur by the base section. The base section, the spring sections and the transition sections therefore form a flange extending surrounding the take-off tongues annularly in circumferential direction.

The manufacture of the take-off ring is possible in a simple manner. For example, the take-off ring may be manufactured from a single piece without connections or joints that is so-to-say integrally. The basis section, the spring section, the transition section, as well as the take-off tongues therefore, consist of the same material and are free of any joints. Preferably, the take-off ring consists of a metal. Alternatively, the take-off ring could also be made of a plastic material.

In a preferred exemplary embodiment, the take-off tongues of the take-off ring are inclined with respect to the longitudinal axis thereof. The inner surfaces of the take-off rings extend at an acute angle with respect to the longitudinal axis of the take-off ring. The inner surfaces of the take-off elements may be disposed on a common truncated cone surface with annular base area. In this embodiment, the inner surfaces are curved in circumferential direction.

Between two adjacent take-off elements a gap may be provided to permit an uninhibited pivot movement about the pivot axis. This gap has in the area between two spring sections preferably an increase gap end which can easily be manufactured by bores between two spring sections. The bores may extend in axial direction and define the pivot axis of the spring section.

The thickness of the take-off tongues measured normal to the respective inner surface is expediently constant. The inner surfaces are in particular planar and without radial projections or recesses so that the can body to be taken off can be easily moved along the inner surfaces.

BRIEF DESCRIPTION OF THE DRAWINGS

Advantageous embodiments of the invention are disclosed hereinafter. The description is limited to essential features of the invention as well as other facts. The drawings are to be considered exemplary of the invention in which it is shown in:

FIGS. 1-3 an exemplary embodiment of a take-off ring in use position adjacent a can to be taken off a deep draw press at various situations during the manufacture of the can body;

FIG. 4 an exemplary embodiment of the take-off ring according to FIG. 1 in a view taken in an axial longitudinal direction;

FIG. 5 the take-off ring in a sectional view taken along line A-A of FIG. 4;

FIG. 6 a perspective representation of an individual take-off element of the take-off ring according to FIGS. 4 and 5; and,

FIG. 7 a schematic representation of the pivot movement of a take-off element about the pivot axis of a spring section.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS

FIGS. 4 and 5 show a preferred exemplary embodiment of a take-off ring 10. The take-off ring 10 is preferably installed in an apparatus for the manufacture of can bodies 11. Such an apparatus can also be called a deep-draw press 12 and is shown schematically in FIG. 1. The deep draw press 12 includes a down holder 13 with a hollow cylindrical down holder section 14. The down holder 13 can be moved by a down holder drive 15 in an operating direction Z. The operating direction Z extends parallel to the longitudinal axis of the down holder 13.

Co-axially with regard to the down holder 13 a drawing plunger 18 is arranged. The drawing plunger 18 can be moved in this movement through the hollow-cylindrical down holder section 14 by a plunger drive 19 into a draw-down or deep-draw opening 20 of a lower tool 21 provided herefor. The draw-down opening 20 in the lower tool 21 is hollow cylindrical and may have several concentric sections with different radii. The draw-down opening 20 in the lower tool 21 has an entrance opening 22 and an opposite exit opening 23. Co-axially with the draw-down opening 20 and the exit opening 23 the take-off ring 10 is releasably mounted to the lower tool 21, for example, by a screw connection. The longitudinal axes of the draw-down opening 20, of the drawing plunger 18 and the take-off ring 10 form in operating position a common longitudinal axis L.

FIGS. 1-3 show schematically the manufacture of the can body 11. First, a pot-shaped blank 25 is provided on the lower tool 21 coaxially with the entrance opening 22. This pot-like blank 25 is called a “cup”. The down holder drive 15 then moves the down holder in the operating direction Z so that the hollow cylindrical down holder section 14 engages into the blank 25 and presses the bottom of the blank 25 against an annular surface area around the entrance opening 22 of the lower tool 21. Subsequently, the plunger drive 19 moves the drawing plunger 18 in the operating direction Z through the down holder 13 into the hollow-cylindrical draw-down opening 20. In the process, the drawing plunger 18, pressing down the bottom of the blank pulls the blank bottom into the hollow-cylindrical draw-down opening 20. The gap remaining between the outer circumferential surface of the drawing plunger 18 and the inner surface of the draw-down opening 20 determines the thickness of the can wall of the can body 11 to be manufactured. It can be reduced stepwise within the draw-down opening 20. The drawing plunger moves the can body manufactured in this way completely out of the exit opening 23. In the process, the drawing plunger 18 and the can body 11 move through the central opening 26 of the take-off ring 10. The take-off ring 10 includes a plurality of take-off elements 27 which are arranged in circumferential direction next to one another. The take-off elements 27 are moved radially outwardly with respect to the longitudinal axis L as it is shown schematically in FIG. 2. After the can body 11 has been moved by the drawing plunger 18 completely through radially the take-off ring 10, the take off elements 27 spring back inwardly because of the spring pre-tension and then directly abut the drawing plunger 18. When now the drawing plunger 18 is moved back by the plunger drive 19 in a direction opposite the operating direction R the take off ring 10 abutting the drawing plunger 18 slides the completed can body 11 off the drawing plunger 18.

In order to keep the needed stroke of the drawing plunger 18 as small as possible, the design of the take-off ring as proposed by the invention provides for a short axial length of the take-off ring. The take-off ring 10 consists of a single material which is for example a metal. It is of an integral design without connecting or joint areas so that a simple and precise manufacture is facilitated.

The take-off ring 10 consists of an annular flange 30 which is arranged coaxially with respect to the longitudinal axis L. An annual area 31 of the annular flange 30 is in contact with the lower tool 21 of the deep draw press 12 when the ring 10 is installed. The plane in which the annular area 31 is disposed extends at a right angle to the longitudinal axis L and forms the upper side of the take-off ring 10. No other components of the take-off ring 10 penetrate the plane of the annular surface 31.

The radially outer part of the annular flange 30 is formed by an annular base section 32. The annular base section 32 is in the circumferential direction U without interruption and has for example a rectangular cross-section. The base section 32 interconnects the take-off elements 27 which are disposed radially within the base section 32 unreleasably with one another. The take-off elements 27 have as seen in a circumferential direction U an angled shape wherein a first leg 33 is part of the annular flange 30. A second leg 34 extending transversely thereto forms a take-off tongue 35.

The first leg 33 of the take-off element 27 is divided into two sections. A spring section 38 connects the take-off element 27 to the base section 32. Between the spring section 38 and the take-off tongue 35 there is a transition section 39. The base section 32 and the spring sections 38 and the transition sections 39 of the take off elements 27 form together the annular flange 30. The thickness of the sections 32, 38, 39 forming the annular flange 30 is constant as measured in the direction of the longitudinal axis L.

The take-off tongue 35 has a first axial end 40 which is connected to the transition section 39. Starting from the first axial end 40, the take-off tongue 35 extends to its second free axial end 41. The take-off tongue 35 includes an inner surface area 42 facing the longitudinal axis L. The inner surface area 42 extends over the whole length of the take-off tongue from the first axial end 40 to the second axial end 41. It forms with the transition area 39 at the first axial end 40 a first edge 43. At the free end 41, the inner surface area 42 ends at a second edge 44. At this second edge 44 the inner surface area 42 forms a front face 45 of the take-off tongue 35 extending about in the direction of the longitudinal axis L. This area transition is about rectangular. In a direction at a right angle with respect to the inner surface 42 the thickness of the take-off tongue 35 is constant. The inner surfaces 42 are planar and without any radial projections or recesses. The take-off ring 10 extends in the longitudinal direction L from the annular area 31 to the free end 41 of the take-off elements 27. As a result, it may be very short in the longitudinal direction L.

In the start-out or rest position of the take-off ring 10, the take-off tongue 35 and in particular the inner surface 42 is inclined with respect to the longitudinal axis L. A straight line extending parallel to the longitudinal axis L intersects the inner surface 42 of the take-off tongue 35 at an angle of inclination α. The inclination angle α is preferably smaller than 10° and is in particular in the range of 3 to 7 degrees.

The inner surface areas 42 of the take-off tongues 35 of the take-off ring 10 are curved in the circumferential direction U of the take-off ring 10. The first edges 43 are disposed on a common radius R1 around the longitudinal axis L and the second edges 44 are disposed on a common second radius R2 around the longitudinal axis L. The second radius R2 is smaller than the first radius R1. The outer diameter of the can body 11 is smaller than the first radius R1 and larger than the second radius R2. The inner surface areas 42 of all take-off elements 27 are disposed on a common truncated cone surface area.

The take-off elements 27 of the take-off ring 10 are interconnected exclusively by the common base section 32. Between two adjacent take-off elements 27 there is a gap 48. In a first gap area 49 between two adjacent take-off tongues 35 and two adjacent transition areas 39, the gap has in the circumferential direction U a constant gap width B. Between the two adjacent spring sections 38 the first gap area 49 becomes the second gap area which forms a gap end 50 that is widened in the circumferential direction U. The widened gap end 50 is formed in the exemplary embodiment by cylindrical bores whose cylinder axes extend parallel to the longitudinal axis L of the take-off ring 10. The cylinder axes 51 of the bores are disposed on a common third radius R3 about the longitudinal axis L. The first gap areas 49 extend in planes which are defined by the longitudinal axis L and a radial direction, wherein two of the planes of adjacent first gap areas 49 form an angle β in the area of preferably 5 to 10 degrees.

With the widened gap ends 50, the first leg 33 of the take-off element 27 is narrowed down between two gap ends 50 as seen in the circumferential direction U. In this way, the spring section 38 is formed which facilitates a pivoting of the transition area 39 together with the take-off tongue 35 about a pivot axis 55. The pivot axes 55 of the take-off elements 27 are disposed on a common radius about the longitudinal axis L which corresponds to the third radius R3.

The common pivot movement of the take-off tongues 35 with the transition section 39 is shown schematically in FIG. 7. As soon as the can body 11 is moved out of the exit opening 23 and reaches the inner surface area 42 of the take-off tongue 35, the pivot movement about the pivot axis 55 starts. Herein the take-off tongue 35 is not only pressed radially outwardly, but there is an additional movement in operating direction Z, that is in the direction of the longitudinal axis L as well as radially thereto. The take-off tongue 35 moves together with the can container 11, a distance in the operating direction Z. In this way, the resistance which the take-off elements 27 generate against the movement of the can body 11 can be kept very low. In this way, the formation of scratches or grooves on the can body is avoided.

After the can body 11 has been moved fully through the take-off ring 10, the take-off elements 27 pivot back to their original position whereby the inner surface areas 42 come into contact with the drawing plunger 18. When the plunger is now retracted in a direction opposite to the operating direction Z the front face of the can wall of the can body 11 abuts the front faces 45 of the take-off tongues 35. That is the front faces 45 form stops areas 46 for the can body 11. The force imparted during the return movement of the drawing plunger 18 and applied via the can body 11 to the take-off tongues 35 is supported by the lower tool 21. The can body 11 is in this way pushed off the drawing plunger 18.

The invention relates to a take-off ring 10 which is provided in particular for use in connection with deep-draw presses 12. It serves for removing a top-shaped can body 11 from a drawing plunger 18. The take-off ring 10 includes a multitude of take-off elements 27 which are arranged uniformly distributed in circumferential direction U and separated in each case by a gap 48. The take-off elements 27 are interconnected by an annular base section 30 which extends around the take-off elements 27 in the circumferential direction U. Radially inwardly a spring section 38 and a transition section 39 of the take-off element follow. The transition section 39 is pivotable by way of the spring section 38 about a pivot axis 55 which extends in the circumferential direction U. From the transition section 29 a take-off tongue 35 extends in a transverse direction away from the transition section 39 toward a free end 41. The front face 45 of the take-off tongue 35 present at the free end 41 forms a support surface 46, which abuts the can body 11 during take off of the can body 11 from the drawing plunger 18. The take-off ring 10 permits a design of short axial length L. It is easy to manufacture and easily exchangeable.

LISTING OF THE REFERENCE NUMERALS

• • 10 take-off ring
  • 11 can body
  • 12 deep-draw press
  • 13 down holder
  • 14 down holder section
  • 15 down holder drive
  • 18 drawing plunger
  • 19 plunger drive
  • 20 draw-down opening or deep-draw opening
  • 21 lower tool
  • 22 entrance opening
  • 23 exit opening
  • 25 blank
  • 26 central opening
  • 27 take-off element
  • 30 annular flange
  • 31 annular area
  • 32 base section
  • 33 first leg
  • 34 second leg
  • 35 take-off tongue
  • 38 spring section
  • 39 transition section
  • 40 first axial end of 35
  • 41 second axial end of 35
  • 42 inner surface area
  • 43 first edge
  • 44 second edge
  • 45 front face
  • 46 stop surface area
  • 48 gap
  • 49 first gap area
  • 50 gap end
  • 51 cylinder axis
  • 55 pivot axis
  • α angle of inclination
  • β angle
  • B gap width of 49
  • L longitudinal axis
  • R1 first radius
  • R2 second radius
  • U circumferential direction
  • Z operating direction

Claims

1. Take-off ring (10), in particular an arrangement (12) for the manufacture of a can body (11), said take-off ring (10) comprising:

an annular base section (32) by which several take-off elements (27) are interconnected,

each take-off element (27) includes a spring section (38) which extends radially inwardly from the base section (32) and has a pivot axis (55) which extends in a circumferential direction (U), each take-off element (27) includes a radially inwardly disposed transition section (39) from which a take-off tongue (35) extends transverse to the radial direction and transverse to the circumferential direction (U) and which is supported so as to be pivotable about the pivot axis (55).

2. Take-off ring (10) according to claim 1, wherein the base section (32) and each take-off element (27) consist of the same material and are manufactured from a single piece without connecting points or joints.

3. Take-off ring (10) according to claim 1, wherein the take-off tongue (35) extends over the full axial length of the take-off ring (10).

4. Take-off ring (10) according to claim 1, wherein the take-off tongue (35) extends in its rest position at an inclined angle with respect to a longitudinal axis (L) of the take-off ring (10).

5. Take-off ring (10) according to claim 1, wherein the take-off tongue (35) having a radially inwardly positioned free end (41), the take-off tongue (35) at its radially inwardly positioned free end (41) has a front face (45) which serves as a support surface (45), which serves as abutment area (46) for the can body (11) to be taken off.

6. Take-off ring (10) according to claim 1, wherein the take-off tongues (35) of the take-off elements (27) each have an inwardly facing planar inner surface area (42).

7. Take-off ring (10) according to claim 6, wherein the inner surface areas (42) of all take-off elements (27) are disposed on the outer surface of a common truncated cone.

8. Take-off ring (10) according to claim 1, wherein each two adjacent take-off elements (27) are separated from each other by a gap (48).

9. Take-off ring (10) according to claim 8, wherein each gap (48) has a gap end (50) proximate pivot axis (55) of increased size which is disposed between the spring sections (38) in circumferential direction (U).

10. In combination with an apparatus for the manufacture of can bodies (11), said apparatus including a lower tool (21) having a hollow cylindrical deep-draw opening (20) with an exit opening (23), the improvement which comprises:

a take-off ring (10) including an annular base section (32) by which several take-off elements (27) are interconnected,

each take-off element (27) includes a spring section (38) which extends radially inwardly from the base section (32) and has a pivot axis (55) which extends in a circumferential direction (U), each take-off element (27) includes a radially inwardly disposed transition section (39) from which a take-off tongue (35) extends transverse to the radial direction and transverse to the circumferential direction (U) and which is supported so as to be pivotable about the pivot axis (55),

the base section (32) arranged coaxially with the exit opening (23) of the deep-draw opening (20) in the lower tool (21) and releasably connected to a mounting surface area surrounding the exit opening (23).