Auxiliary device for replacing an extruder screw

Abstract

Auxiliary device for replacing an extruder screw, characterized in that the auxiliary device has a cylindrical base body which has at one end a receiving device for receiving a tip of an extruder screw, and at the opposite end has a fastening means for attaching a pulling means, characterized in that the receiving device is provided with a snap-in mechanism for attaching the device to the tip of an extruder screw.

Description

[0001] The present invention relates to an auxiliary device for replacing extruder screws, a special screw tip for an extruder screw and a kit for replacing an extruder screw.

[0002] Extrusion processes are widely used, particularly in the plastics and food industries, employing a variety of extrusion systems. In a screw extruder, an extruder screw rotates within an extruder cylinder, generating pressure and temperature through its movement, which continuously transports and processes the material. These extruder screws show signs of wear over time and must be replaced regularly.

[0003] This often requires the extruder screws to be pulled out of the extruder, frequently with considerable force, which often results in damage to the screw or adjacent components. The tools used so far, such as simple pull rods, threaded rods, or improvised devices, do not provide a reliable fixation to the screw. This means that the connection between the pulling device and the screw can slip or loosen during the pulling process, significantly compromising the safety and efficiency of the replacement. Furthermore, screw removal is often physically demanding for the operator, as the screw can be difficult to access and heavily contaminated. The existing devices do not offer a way to securely and controllably fix the screw, increasing the risk of damage to the screw or the extruder.Overall, the replacement process is inefficient, time-consuming, and involves increased risks for both people and machines.

[0004] Therefore, there is a need for suitable tools that facilitate the replacement of an extruder screw and minimize the risk of damage to the rest of the machine.

[0005] This need is addressed by the present invention, which provides an auxiliary device that enables a simple and safe replacement of extruder screws.

[0006] Against this background, the present invention relates to an auxiliary device for replacing extruder screws as defined in claim 1. Preferred embodiments are set out in the dependent and collateral claims.

[0007] A first object of the present invention is thus an auxiliary device for replacing an extruder screw, wherein the auxiliary device has a cylindrical base body which has at one end a receiving device for receiving a tip of an extruder screw and at the opposite end a fastening means for attaching a traction element, wherein the receiving device is provided with a snap-in mechanism for attaching the device to the tip of an extruder screw.

[0008] The auxiliary device according to the invention serves to facilitate and make the replacement process of the extruder screw safer. For this purpose, the auxiliary device has a cylindrical base body at one end of which a receiving device is arranged, designed to receive the tip of an extruder screw. The auxiliary device can thus be placed onto the tip of the extruder screw and securely fastened by means of the snap-in mechanism. The fastening device arranged at the opposite end of the base body allows for the attachment of suitable pulling elements, with the aid of which the extruder screw can be pulled out of the screw cylinder.

[0009] The combination of a cylindrical base, a receiving device with a locking mechanism, and a fastening means for a pulling force enables the safe, simple, and efficient removal of the extruder screw. The auxiliary device is designed for use even in confined spaces and with minimal effort. The auxiliary device according to the invention thus contributes to reducing downtime and increasing workplace safety when replacing extruder screws.

[0010] To ensure a secure connection between the screw and the auxiliary device, the auxiliary device can be further equipped with locking elements in its receiving device. Therefore, a preferred embodiment is one in which the receiving device of the auxiliary device has locking elements in its periphery that serve to fix the auxiliary device to the tip of the extruder screw. Such locking elements can be designed, for example, as spring-loaded locking pins, radially movable bolts, or flexible snap hooks. It is possible for the locking elements to be arranged such that, when the auxiliary device is placed on the tip of the extruder screw, they automatically engage in a corresponding recess or indentation in the screw tip, thereby ensuring secure fixation.

[0011] Alternatively, the locking elements can also be manually actuated, allowing the user to selectively engage or disengage the locking mechanism. The number, shape, and arrangement of the locking elements can be adapted to the specific geometry of the extruder screw. For example, several locking elements can be evenly distributed around the circumference of the mounting device to ensure a centered and stable fixation.

[0012] The snap-in elements can be designed as an integral part of the receiving device or inserted into the receiving device as separate components.

[0013] The auxiliary device is designed in such a way that the locking elements engage in an undercut in the screw tip by rotating the auxiliary device placed on the screw tip.

[0014] To prevent the auxiliary device from unintentionally coming loose, it can also be equipped with a locking device. This could, for example, be a locking mechanism that is pre-tensioned by placing the auxiliary device onto the screw tip.

[0015] Another problem when replacing extruder screws is that the screw tips often lack specific fastening features, making it difficult to attach chains or other pulling devices. This results in cumbersome and time-consuming work processes that frequently require multiple people and additional tools. Furthermore, the risk of injury from slipping or inadequately secured pulling devices is increased.

[0016] The auxiliary device according to the invention is therefore provided with a fastening element that allows for the easy attachment of suitable traction elements. The fastening element is advantageously designed as an eyelet, ring screw, or bayonet fitting. For example, an eyelet can be provided through which a traction element, such as a rope or chain, can be threaded and fastened. Alternatively, the fastening element can be designed as a ring screw, which allows for easy screwing and unfastening of the traction element. The use of a bayonet fitting is also conceivable, allowing for quick and secure connection and release of the traction element. The selection of the respective fastening element can be adapted to the specific requirements of the application and the local conditions. It is also possible for the fastening element to be attached to the auxiliary device in an interchangeable manner to ensure flexible handling.In this case, the fastening element is preferably a thread provided in the auxiliary device, into which, for example, a ring bolt can be screwed. Due to the different embodiments of the fastening element, the auxiliary device can be used in a variety of ways and adapted to different pulling forces and working environments.

[0017] Another aspect of the present invention is a tip for an extruder screw, which is provided with an undercut that can be used to attach an auxiliary device according to the invention. Such an undercut can, for example, be designed as a circumferential groove, an annular recess, or another suitable geometry that allows the locking or hooking of locking elements of the auxiliary device. It is conceivable that the undercut is designed in such a way as to support a positive-locking connection between the screw tip and the auxiliary device, thereby ensuring a secure hold during the drawing process.

[0018] Alternatively, the undercut can also be designed as a local recess, a notch profile, or a combination of several geometries to accommodate different types of snap-in elements or fastening mechanisms. The precise design of the undercut can be adapted to the specific extruder screw design and the auxiliary device used.

[0019] The use of an undercut at the screw tip can further facilitate the extruder screw replacement process and increase handling safety. Therefore, creating an undercut represents an advantageous option for improving the connection between the screw tip and the auxiliary device.

[0020] Another aspect of the invention is a kit for replacing an extruder screw, comprising an auxiliary device and a screw tip according to the invention. The screw tip is designed to be suitable for attachment to an extruder screw and has an undercut for attaching the auxiliary device.

[0021] When attaching the auxiliary device to the extruder screw, the mounting device is placed onto the screw tip in such a way that the locking mechanism engages in the undercut of the screw tip. This creates a positive-locking and secure connection between the auxiliary device and the screw tip. This connection ensures that the auxiliary device remains firmly attached to the extruder screw throughout the entire replacement process and cannot detach unintentionally.

[0022] The kit is designed to simplify extruder screw replacement and increase workplace safety. The combination of a specially adapted screw tip with an undercut and a matching auxiliary device with a snap-in mechanism enables easy, quick, and reliable attachment. The fastener at the opposite end of the auxiliary device's cylindrical base allows for the attachment of a pulling cord, enabling the extruder screw to be pulled out of the extruder housing in a controlled manner.

[0023] The present invention is further illustrated by the following figures, which are in no way to be understood as limiting the inventive concept. Fig. 1a and Fig. Figure 1b shows perspective views of an embodiment of the auxiliary device according to the invention. Fig. Figure 1c shows a perspective view of the auxiliary device according to the invention, which is mounted on a screw tip. Fig. Figure 2 shows an embodiment of a snail tip according to the invention.

Claims

[1] Auxiliary device for replacing an extruder screw, characterized by , that the auxiliary device has a cylindrical base body which has at one end a receiving device for receiving the tip of an extruder screw, and at the opposite end a fastening means for attaching a traction element, characterized by that the receiving device is equipped with a locking mechanism for attaching the device to the tip of an extruder screw. [2] Auxiliary device according to claim 1, characterized by that the receiving device has locking elements in its periphery for fixing the auxiliary device to the tip of an extruder screw. [3] Auxiliary device according to claim 2, characterized by that the locking elements are designed as an integral part of the receiving device or are inserted into the receiving device as separate components. [4] Auxiliary device according to at least one of the preceding claims, characterized by that the auxiliary device has a safety device. [5] Auxiliary device according to at least one of the preceding claims, characterized by that the fastening device is an eyelet, ring screw or bayonet fitting. [6] Screw tip for an extruder screw, characterized by that the tip has an undercut for attaching an auxiliary device according to at least one of claims 1 to 5. [7] Kit for replacing an extruder screw comprising an auxiliary device according to at least one of claims 1 to 5 and a screw tip according to claim 6, wherein the screw tip is adapted for attachment to an extruder screw and the auxiliary device is attached to the extruder screw in such a way that the locking mechanism engages in the undercut of the screw tip.

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