belt pulley

Abstract

Belt pulley (1) for roller shutters with a winding core (1.1) and with at least one edge disc (1.2a, 1.2b) for limiting the winding space of the roller shutter belt (1.7) comprising a clamping element (2) for fixing the roller shutter belt (1.7) to the belt pulley (1).

Description

[0001] The invention relates to a belt pulley according to claim 1. Belt pulleys serve to hold the roller shutter belt in a belt-driven roller shutter. Typically, such a belt pulley is rotationally fixed to the shaft that holds the roller shutter curtain. Conventional belt pulleys have a protruding, nose-like extension on their winding core, into which the end of the belt, provided with a corresponding hole, is simply hooked. After prolonged use and due to material fatigue, this protruding extension, made of plastic or thin sheet metal, often breaks off. Consequently, the roller shutter can no longer be operated, as there is no longer a positive connection between the belt and the belt pulley, and the belt can no longer cause rotation of the belt pulley or the roller shutter shaft. Since repair is not possible, at least the belt pulley usually has to be replaced, which incurs high repair costs.

[0002] The invention provides a novel belt pulley that functions reliably even after prolonged operation of the roller shutter, thus avoiding high repair costs. An embodiment of the invention is explained in more detail below with reference to the drawing. This shows Fig. 1: A schematic representation of a roller shutter belt pulley Fig. 2: a cut through the belt pulley Fig. 3: a clamping element in a first position Fig. 4: a clamping element in a second position

[0003] Fig. Figure 1 shows a schematic representation of the pulley 1 of a roller shutter. The pulley 1 serves to wind up a roller shutter strap with which the roller shutter is operated. For this purpose, the pulley 1 is positively and non-rotatably connected to the roller shutter shaft (not shown) onto which the roller shutter curtain is wound. Pulling or releasing the roller shutter strap causes the pulley and the roller shutter shaft, which is coupled to it in a rotationally fixed manner, to rotate. This winds up or down the roller shutter curtain. The in Fig. A schematically depicted belt pulley 1 comprises a substantially hollow cylindrical winding core 1.1. The roller shutter belt 1.7 of the roller shutter is wound onto this winding core 1.1 when the roller shutter curtain is lowered. When the roller shutter is opened, the roller shutter belt is unwound from the winding core 1.1 and wound onto a belt winder accessible in the room. According to the invention, a clamping element 2 is arranged inside the winding core 1.1. The clamping element 2 is designed as a hollow cylindrical cup, which is rotatably mounted coaxially inside the winding core 1.1 on a shaft (not shown in detail in the drawing). The clamping element 2 is acted upon by a torsion spring 2.1, the force of which causes the clamping element 2 to assume essentially two rotational positions, as will be explained below. Fig. Figure 1 shows a slot 1.5 in the casing of the winding core 1.1, through which the end piece of the roller shutter strap 1.7 can be inserted into the interior of the winding core 1.1. Fig. Figure 2 illustrates the arrangement of the clamping element 2 within the belt pulley 1 using a schematic sectional view of the belt pulley 1. The clamping element, which is essentially hollow and cylindrical, is rotatably mounted coaxially to the winding core inside it on a shaft (not shown). A slot 2.5 is also provided in the wall of the clamping element 2, through which the end of the roller shutter belt 1.7 can be inserted further into the interior of the clamping element 2. Based on Fig. 3 and Fig. 4 The process of threading and clamping the roller shutter strap 1.7 is explained below. Fig. Figure 3 first illustrates how to thread the roller shutter strap 1.7. To do this, the clamping element is first rotated until the two slots 1.5 and 2.5 are aligned opposite each other. This tensions the torsion spring 2.1. After inserting the roller shutter strap 1.7 through the aligned slots 1.5 and 2.5 into the interior of the clamping element 2, the clamping element 2 is released. Under the force of the previously tensioned torsion spring 2.1, the clamping element 2 takes the Fig. Figure 4 shows the rotational position in which the roller shutter strap 1.7 is securely clamped. The roller shutter strap 1.7 can now be reliably wound onto or unwound from the winding core 1.1.

[0004] To increase the clamping effect of the clamping element 2, the outer surface of the clamping element 2 facing the inner wall of the winding core 1.1 can advantageously be designed to increase friction. This can be advantageously achieved by roughening the surface of the clamping element 2. In a further embodiment of the clamping element 2, barbs are incorporated into the outer surface of the clamping element, which engage with the clamped roller shutter strap 1.7. Reference symbol list 1 belt pulley 1.1 Winding core 1.2a Edge disc 1.5 slot 1.7 Roller shutter strap 2 clamping elements 2.1 Torsion spring 2.5 slots

Claims

[1] Belt pulley (1) for roller shutters with a winding core (1.1) and with at least one edge disc (1.2a, 1.2b) for limiting the winding space of the roller shutter belt (1.7) comprising a clamping element (2) for fixing the roller shutter belt (1.7) to the belt pulley (1). [2] Belt pulley (2) according to claim 1, characterized by , that the clamping element (2) is designed as an essentially hollow cylindrical body which is rotatably mounted inside the winding body (1.1) and coaxially to it. [3] Belt pulley (1) according to one of the preceding claims, characterized by , that the clamping element (2) is subjected to a torsion spring (2.1) by the force of which the clamping element (2) can assume essentially two rotational positions. [4] Belt pulley (1) according to one of the preceding claims, characterized by, that slots (1.5, 2.5) are provided in the outer surfaces of the winding core (1.1) and the clamping element (2), which can be aligned with each other by rotating the clamping element (2) so that the roller shutter belt (1.7) can be inserted into the interior of the clamping element (2).

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