HEATING DEVICE

Abstract

Heating device for locally heating of an injection mold cavity wall, comprising: a base plate, an actuator located on the base plate, to perform a linear movement; a heated stamp connected to the actuator and driven by the actuator, to perform a linear movement in direction to and from the injection mold cavity wall; wherein the heated stamp is located below the base plate and the actuator is located on top of the base plate, and wherein the base plate comprises an opening through which a pin extends for transferring the linear movement from the actuator to the heated stamp.

Claims

1. A heating device for locally heating of an injection mold cavity wall, comprising: a base plate, an actuator located on the base plate to perform a linear movement; a heated stamp connected to the actuator and driven by the actuator, to perform a linear movement in a direction to and from the injection mold cavity wall; wherein the heated stamp is located below the base plate and the actuator, and wherein the base plate comprises an opening through which a pin extends for transferring the linear movement from the actuator to the heated stamp.

2. The heating device according to the preceding claim 1, wherein the base plate is integrally formed in a manifold of a hot runner system, so that it is part of the manifold.

3. The heating device according to claim 1, comprising one or more alignment elements to align the base plate to the injection mold cavity wall connected to the base plate extending in direction of the heated stamp below the base plate, to hold a position relative to the injection mold cavity wall.

4. The heating device according to claim 1, wherein the baseplate comprises bores connectable to fluid to drive the actuator or a cooling pump to protect the actuator from heat.

5. The heating device according to claim 1, further comprising a position nut holding the pin, wherein the position nut is located in a threaded bore within the actuator.

6. The heating device according to claim 5, wherein the threaded bore within the actuator extends to the upper surface of the actuator, so that an access from the upper surface of the actuator is enabled, to allow access to the position nut and or lock nut.

7. The heating device according to claim 1, further comprising a position sensor providing information of the position of the heated stamp.

8. The heating device according to claim 1, further comprising screws laterally penetrating the heated stamp, to clamp the pin, which extends into a bore within the heated stamp; a locking ring; a cotter pin to hold the pin against the heated stamp; and a thread on the pin on which the heated stamp is screwed.

9. The heating device according to claim 1, further comprising anti-rotation surfaces preventing the heated stamp to rotate relative to the base plate.

10. The heating device according to claim 1, further comprising a bracket enabling the heating device to be fixed to a hot runner system.

11. The heating device according to claim 10, wherein screws secure the bracket to the manifold of a hot runner system.

12. The heating device according to claim 1, wherein the actuator is electric driven or fluid driven.

13. The heating device according to claim 1, further comprising a temperature sensor attached to a non-moving part of the heating device for measuring the heat of the injection mold cavity wall in the vicinity where the heated stamp is able to contact the injection mold cavity wall.

14. The heating device according to claim 1, further comprising a heating element around the heated stamp that is rotatably mounted on the heated stamp or a shank in which the heated stamp is moving up and down.

15. A hot runner system comprising holding means to physically hold a heating device for locally heating of an injection mold cavity wall, wherein the holding means is configured so that the main weight of the heating device is carried by the hot runner system, wherein the heating device comprises an actuator to perform a linear movement; a heated stamp connected to the actuator and driven by the actuator, to perform a linear movement in direction to and from the injection mold cavity wall, and wherein the heating device is driven by the same media or energy as provided for the hot runner system.

16. The hot runner system according to claim 15, wherein the heating device share the same sensor cables and/or cable channels and/or adapter plates and/or connector plates at which the connectors for the hot runner system terminate.

17. The hot runner system according to claim 15, wherein the heating device comprises a baseplate to which on one side the actuator is fixed and wherein the heated stamp is located on the other side of the base plate and base plate comprises an opening through which the heated stamp and the actuator are connected, wherein the base plate is connected to a manifold or is integrated into the manifold being a part of the manifold.

18. The hot runner system according to the preceding claim 15, wherein the media are fluids, hydraulic or pneumatic fluids and/or electricity.

19. The hot runner system according to claim 15, wherein the heating device is a heating device according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0045] FIG. 1 shows a sectional view of the heating device according to the invention.

[0046] FIG. 2 shows a sectional view of the upper part of the heating device according to the invention focusing on the actuator.

[0047] FIG. 3 shows a section view of the lower part of the heating device according to the invention focusing on the heated stamp and the temperature sensor.

[0048] FIG. 4A shows a side view of the tip of the heating device.

[0049] FIG. 4B shows a sectional bottom view from the tip to the actuator of the heating system along E-E.

[0050] FIG. 4C shows the pin tube with the anti-rotation means.

[0051] FIG. 5A shows a sectional view of the heated stamp and the pin along F-F.

[0052] FIG. 5B shows a perspective view of the heated stamp from the bottom.

[0053] FIG. 5C shows a top view of the heated stamp and the pin.

[0054] FIGS. 6A and 6B show the mounting of the heating device to a hot runner system sharing the same cable channel and connector plates.

[0055] FIGS. 7A and 7B show the linear movement of the heated stamp on and off.

[0056] FIG. 8 shows the invention in sectional directly mounted on a manifold.

[0057] FIG. 9 shows a perspective view of the heating device mounted on a manifold.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0058] In the following embodiments shown in the Figs. as discussed, without the intention to limit the scope of protection of the claims.

[0059] FIG. 1 shows a sectional view of a heating device 1 for locally heating of an injection mold cavity wall (2). A base plate 3a/3b, which is located between a heated stamp 5 and an actuator 4. The actuator 4 is located on top the base plate (in the figure on the right side), to perform a linear movement 27 (FIG. 2). In the center of the actuator is a bore which is at least partially threaded. The bore extends from the top to the bottom of the actuator, so that pin 7 located and fixed within the bore can be introduced from both sides. At the bottom end of the pin a heated stamp 5 is fixed. The pin translates the linear movement of the actuator to the heated stamp. By this linear movement the heated stamp is moved in direction the injection mold cavity wall and brought into contact with the injection mold cavity to locally heat the injection mold cavity wall (FIG. 7A).

[0060] The heated stamp 5 is located below the base plate and the actuator 5 is located on top of the base plate. A vice versa implementation is also possible. The base plate comprises an opening 6 through which the pin 7 extends for transferring the linear movement from the actuator to the heated stamp.

[0061] The pin is surrounded by a pin tube 32 which also serves as an anti-rotation means. At distinct areas of the (top and or bottom) pin tube 32 flatted side walls are designed which are in contact with flatted areas of the heated stamp and the base plate 3A, which prevents the heated stamp to rotate.

[0062] The pin tube is made of a less heat conductive material to reduce heat loss from the heated stamp. This part does not move relative to the base plate.

[0063] The pin tube is fixed in the base plate by screws 20 and or by the base plate 3b. A slide offset of the screws to the groove takes care that the pin tube is pressed against the base plate. This could also be used to define the angle of the heated stamp if rotation would be adjustable (no anti-rotation flats on pin tube and base plate).

[0064] Within the central bore of the actuator a position nut 9 and a lock nut 10 are located to fix the requested position of the heated stamp and set a stroke limitation. The nuts are screwed into the threaded bore. The position nut embraces a pin head 18 and holds the pin which enables the actuator to drive the pin in both directions through an opening 6 in the base plate. The lock nut has the function of counter screws

[0065] Parallel to the pin a temperature sensor 19 extends from the base plate to measure the temperature on the surface of the injection mold cavity in vicinity of the contact area of the heated stamp.

[0066] On the upper surface 12 of the actuator a position switch 13 is located. In this area anti-rotate secured switching cam held by hollow screw is located. The hollow structure allows access to the position nut and the lock nut below.

[0067] FIG. 2 shows a sectional view of actuator 4 on top of the base plate 3. The base plate and the actuator 4 are held together with screws 23, which extend from the bottom of the base plate through the base plate into the bottom surface of the actuator 4. The base plate also comprises fluid inlet/outlet 25 for fluid (air/hydraulic) to drive the actuator and/or for cooling purposes to cool the actuator to protect the actuator from the heat of the surrounding components

[0068] The inlet/outlet 25 can be located at different positions on top at the side or at the bottom of the base plate. In some embodiments the fluid inlet/outlets are located directly at the housing of the actuator.

[0069] Also, in the baseplate set pin(s) 8 are located to define and keep the distance between the injection mold cavity 2 and the heated stamp. The set pins are located in bores preferably blind bores and are pressed into the bores.

[0070] Furthermore, the outlet of the temperature sensor extends below the base plate to a side of the base plate.

[0071] The arrow 27 shows the linear movement directions of the actuator. Position switch 13 is triggered by a switch cam 24 that is driven by the linear movements of the actuator. The switch cam 24 is fixed to an upper end of the threaded bore by a hollow screw 21 which extends into the threaded bore and is located above the lock nut and position nut.

[0072] FIG. 3 shows a sectional view of the lower part of the invention. The temperature sensor 19 extends through a bore/passage 15 in the heated stamp 5. A gap 30 in the bore passage 15 prevents an overheating of the temperature sensor 19 and its cables. Additionally, a protection pipe 31 surrounds the temperature sensor and its cables as a heat protection. The heated stamp has at its outer surface a heating coil or heating element 22 which is wrapped around a core of the heated stamp. The core has notches surrounding the core in the shape of a coil. The valve pin is movable up and down in a pin tube 32 which has at each end anti-rotation flat surfaces 16 that prevent rotation of the heated stamp.

[0073] FIG. 4A shows a sided view of the heated stamp with the rotatable heating device 33 and the outlet 34 of the heating. FIG. 4b shows a sectional view along the cut E-E of FIG. 4a. FIG. 4b shows that the heater/heating can be turned to change the location of an outlet 34, so that the cabling can be adapted to the location when fixed to the hot runner system.

[0074] FIGS. 5A-5C show the heating device 33 and the outlet 34 in a sectional view. Also, it is disclosed that heated stamp 5 is fixed to the pin 7 by screws 14, which are screwed into threaded bores extending into a center bore in which the pin is located.

[0075] FIG. 6A shows a top view of the heating device attached by a bracket 37 to the hot runner system 35. Due to the slotted bracket a flexible mount to the hot runner system is possible. In the FIG. 6A the bracket is L-shape and is on one end connected to the manifold 36 of the hot runner system 35 and on the other end to the heating device. In a possible embodiment the bracket is attached to the base plate of the heating device. Different shapes for both the heating device and the brackets are possible (like a straight bracket, a rounded bracket, etc.).

[0076] Supports for adaptation on bracket or holding means take care for flexible mounting on hot runner system.

[0077] Sensor cables and actuator powering (oil, air or electric) is integrated in the same cable channel and/or connector plate like the sensor and/or actuator powering of the hot runner system.

[0078] Complete system has everything included no separate assembling is necessary.

[0079] FIG. 6B shows a side view of FIG. 6A, where the slotted bracket can be seen. The bracket 37 is screwed to the manifold and the base plate. Each of them has threaded bores in which screws extend.

[0080] This allows a flexible mounting on the hot runner since slots on bracket or holding means 17 take care for flexible mounting on the hot runner system. The holding means comprise screws, the bracket 37, and bushings between the bracket and the screws.

[0081] FIG. 7A shows that the heated stamp 5 is in contact with the injection mold cavity wall 2 and is heating the contact area to improve the quality of the injected plastic 39. FIG. 7b shows the heated stamp 5 removed from the injection mold cavity wall 2 so that the plastic can cure (e.g., solidify and/or harden).

[0082] FIG. 8 shows a sectional view through a device according to FIG. 9. Between the manifold 36 and the actuator 4, a cooling device 40 is located, to prevent heat damage to the actuator. Base plate 3a is located directly on the manifold 36. The heating device 22 is designed as a sleeve that can be rotated around the heated stamp 5.

[0083] The above description is intended to be illustrative, not restrictive. The scope of the invention should be determined with reference to the appended claims along with the full scope of equivalents. It is anticipated and intended that future developments will occur in the art, and that the disclosed devices, kits and methods will be incorporated into such future embodiments. Thus, the invention is capable of modification and variation and is limited only by the following claims.

LIST OF REFERENCE NUMERALS

[0084] 1 heating device [0085] 2 injection mold cavity wall [0086] 3a/b base plate [0087] 4 actuator [0088] 5 heated stamp [0089] 6 opening in the base plate [0090] 7 pin [0091] 8 dowel pin(s) [0092] 9 position nut [0093] 10 threaded bore [0094] 11 lock nut [0095] 12 upper surface of the actuator [0096] 13 position switch [0097] 14 screws clamping the pin [0098] 15 bore/passage within the heated stamp [0099] 16 anti-rotation means [0100] 17 holding means [0101] 18 pin head [0102] 19 temperature sensor [0103] 20 set screw [0104] 21 hollow screw [0105] 22 heating [0106] 23 screw to fix the actuator to the base plate [0107] 24 Switch cam [0108] 25 fluid inlet/outlet [0109] 26 Shank [0110] 27 stroke path/linear movement [0111] 28 outlet of the temperature sensor [0112] 30 gap in the bore/passage [0113] 31 protection pipe/lance of the temperature sensor [0114] 32 pin tube [0115] 33 Rotatable heating around the heated stamp or shank [0116] 34 outlet of the heating [0117] 35 hot runner system [0118] 36 manifold of the hot runner system [0119] 37 slotted bracket to flexibly holding the heating device [0120] 38 connector plate [0121] 39 plastic [0122] 40 Cooling