METHOD FOR MANUFACTURING AN INJECTION DEVICE WITH A BYPASS CHANNEL AND TOOL FOR THIS PURPOSE

Abstract

A tool and a method for manufacturing a bypass in an injection device are disclosed. The preforms of the injection device are inserted into a tool. A partial region of the cylindrical portion is heated by a heat source. The heated partial region of the cylindrical portion is plastically deformed with a male die part of the tool, so that the bypass channel is formed.

Claims

1. A method for manufacturing an injection device with a bypass channel, comprising the following steps: inserting a preform into a tool so that the preform partially rests with a cylindrical outer surface of a cylindrical portion in the tool; heating a partial region of the cylindrical portion; inserting a male die part into the cylindrical portion substantially in an axial direction; displacing the male die part in a radial direction on a cylindrical inner surface of the cylindrical portion of the preform; and pressing the male die part into the heated partial region of the cylindrical portion and thereby forming the bypass channel by plastic deformation of the heated partial region.

2. The method of claim 1, wherein the partial region of the cylindrical portion is heated to a temperature with a heat source, so that the material of the preform can be plastically deformed by a pressure of the male die part in the radial direction.

3. The method of claim 2, wherein the heating of the partial region of the cylindrical portion is performed by means of radiant heat and/or contact heat.

4. The method according to claim 1, wherein the preform is injection molded from cyclo-olefin copolymer, cyclic olefin polymer or polypropylene.

5. The method according to claim 1, wherein by the depression of the male die part in the heated partial region of the cylindrical portion by plastic deformation, an undercut is formed in the partial region of the cylindrical portion, wherein the undercut defines the bypass channel.

6. A tool for manufacturing an injection device with a bypass channel, wherein the tool is configured such that it supports at least one cylindrical portion of the preform, the tool comprises: a heat source is arranged in the tool for heating a partial region of the cylindrical portion of the preform opposite a cylindrical outer surface of the cylindrical portion; and a male die part of the tool is provided, which can be moved into the preform in an axial direction and in the preform in a radial direction towards the heated partial region.

7. The tool according to claim 6, wherein the heat source is a contact and/or radiant heat source.

8. The tool according to claim 6, wherein the tool has formed a stop for a handle of the preform, so that the preform with the partial region to be heated is reproducibly positioned opposite to the heat source of the tool.

9. The tool according to claim 6, wherein the male die part is attached to a handle, by means of which the male die part is insertable into the preform in the axial direction, movable in the preform in the radial direction towards the heated partial region, and a pressure is exercisable on the heated partial region, so that the male die part forms the bypass channel.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Various embodiments are disclosed, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, in which:

[0021] FIG. 1 is a sectional view of a preform along a longitudinal axis;

[0022] FIG. 2 is a sectional view of the preform shown in FIG. 1 positioned in the tool;

[0023] FIG. 3 is a sectional view of the preform positioned in the tool and in which the bypass channel is formed; and

[0024] FIG. 4 is a sectional view of the injection device according to the invention with the formed bypass channel.

DETAILED DESCRIPTION OF THE INVENTION AND EMBODIMENTS

[0025] At the outset, it should be appreciated that like drawing numbers on different drawing views identify identical, or functionally similar, structural elements. It is to be understood that the claims are not limited to the disclosed aspects. The illustrated embodiment for the formation of a bypass channel for an injection device represents only one possible embodiment of how the inventive method can be configured. This is not to be construed as limiting the invention.

[0026] Furthermore, it is understood that this disclosure is not limited to the particular methodology, materials and modifications described and as such may, of course, vary. It is also understood that the terminology used herein is for the purpose of describing particular aspects only, and is not intended to limit the scope of the claims.

[0027] It should be appreciated that the term substantially is synonymous with terms such as nearly, very nearly, about, approximately, around, bordering on, close to, essentially, in the neighborhood of, in the vicinity of, etc., and such terms may be used interchangeably as appearing in the specification and claims. It should be appreciated that the term proximate is synonymous with terms such as nearby, close, adjacent, neighboring, immediate, adjoining, etc., and such terms may be used interchangeably as appearing in the specification and claims.

[0028] Moreover, as used herein, and/or is intended to mean a grammatical conjunction used to indicate that one or more of the elements or conditions recited may be included or occur. For example, a device comprising a first element, a second element and/or a third element, is intended to be construed as any one of the following structural arrangements: a device comprising a first element; a device comprising a second element; a device comprising a third element; a device comprising a first element and a second element; a device comprising a first element and a third element; a device comprising a first element, a second element and a third element; or, a device comprising a second element and a third element.

[0029] Adverting now to the Figures, FIG. 1 shows a sectional view of a preform 5 for the manufacture of an injection device 10 with a bypass channel 2 (see FIG. 4). The preform 5 consists of a cylindrical portion 8, which is aligned along a longitudinal axis L. The cylindrical portion 8 defines a cylindrical outer surface 6 and a cylindrical inner surface 7. Similarly, the preform 5 has formed a handle 11, which can be used in the manufacturing process for the positioning of the preform 5 in a tool 20 (see FIG. 2).

[0030] FIG. 2 likewise shows a sectional view along the longitudinal axis L of the preform 5. The preform 5 is already positioned in a specially configured tool 20 here. The tool defines a stop 23, which cooperates with the handle 11 of the preform 5. As a result, a reproducible positioning of the preform 5 in the tool 20 is achieved. The tool 20 also includes a heat source 24 suitable for heating a partial region 9 of the cylindrical portion 8 of the preform 5. The heat source 24 may be in the form of a contact heat source and/or a radiant heat source. The preform 5 thus rests with a cylindrical outer surface 6 of the cylindrical portion 8 in the tool. The heat source 24 heats the partial region 9 of the cylindrical portion 8 to a temperature such that the material of the preform 5 can be plastically deformed. Simultaneously with the heating of the partial region 9 of the cylindrical portion 8, a male die part 21 can be inserted in the axial direction A in the preform 5. Preferably, the male die part 21 is attached to a handle 22.

[0031] FIG. 3 shows the situation that the male die part 21 has been moved in a radial direction B toward the partial region 9 of the cylindrical portion 8. Preferably, the preform 5 is injection molded from a thermoplastic material. In particular, for the preform 5, the materials COC, COP and PP are used. The movement of the male die part 21 in the radial direction B is effected substantially by the handle 22. As soon as the male die part 21 reaches the cylindrical inner surface 7 of the cylindrical portion 8, a pressure P in the radial direction B is exerted on the male die part 21 via the handle 22, which ensures plastic deformation of the heated partial region 9.

[0032] FIG. 4 shows a sectional view of the injection device 10 produced by the method according to the invention along the longitudinal axis L. The bypass channel 2 is formed in the cylindrical portion 8. In this case, the cylindrical portion 8 is arched outwards from the cylindrical inner surface 7 in the partial region 9 (see FIGS. 2 and 3), so that thereby the cylindrical portion 8 of the injection device 10 has formed an undercut 4. Furthermore, a piston 12 can be inserted into the injection device 10, with which the material present in the injection device 10 can be discharged through a nozzle 14 of the injection device 10.

[0033] It will be appreciated that various aspects of the disclosure above and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.

LIST OF REFERENCE SIGNS

[0034] 2 Bypass channel

[0035] 4 Undercut

[0036] 5 Preform

[0037] 6 Cylindrical outer surface

[0038] 7 Cylindrical inner surface

[0039] 8 Cylindrical portion

[0040] 9 Partial region

[0041] 10 Injection device

[0042] 11 Handle

[0043] 12 Piston

[0044] 14 Nozzle

[0045] 20 Tool

[0046] 21 Male die part

[0047] 22 Handle

[0048] 23 Stop

[0049] 24 Heat source

[0050] A Axial direction

[0051] B Radial direction

[0052] L Longitudinal axis

[0053] P Pressure