WO2005043718A1

WO2005043718A1 - Tubular motor with braking device

Info

Publication number: WO2005043718A1
Application number: PCT/IT2004/000526
Authority: WO
Inventors: Massimo Vigano'; Walter Defendenti
Original assignee: Cherubini Spa
Priority date: 2003-10-31
Filing date: 2004-09-27
Publication date: 2005-05-12
Also published as: ITMI20030510U1; ITMI20030510V0; CN1875535A

Abstract

The present invention relates to a tubular motor (1) for making awnings, curtains and the like, provided with a braking device comprising a disc (5), a support (3) the braking device is made in such a manner that the disc (5) and the plate (4) are in contact when the braking device is operating and not in contact when the braking device is not operating; the disc (5) is mechanically anchored to the support (3)

Description

Title

Tubular motor with braking device

Description The present invention relates to a tubular motor for the movement of awnings, curtains and the like, provided with a brake device. As is known, tubular motors are movement devices whose casing is substantially in the form of a tube and can therefore be housed within the roller tube of awnings, curtains and the like. The tubular motor's movement is provided by an electric motor. The tubular motor very often comprises a speed reducer mechanism coupled to the electric motor. In this case, it should more properly be called a tubular reducing gear. In known tubular motors, the brake device comprises a disc, a disc support and a plate. In general, the plate rotates rigidly with the shaft of the electric motor and the support and its relative disc are rigid with the casing of the tubular motor. In general, the brake device is formed such that, in order to brake the electric motor until it completes to a complete standstill, the plate is alongside the disc creating sliding friction between the plate and the disc. It will be appreciated that the effect of the brake device ends when the disc and the plate are separated. The disc is conventionally made from silicone rubber and the support is conventionally made from plastics. The connection between the disc and the support is conventionally provided in two different ways: by adhesion or by joint moulding. The first method is simple to carry out; however, it has the drawback that the glues adapted for such a purpose are very expensive because they have to be able to adhere on one side to the silicone rubber and on the other side to the plastics material (use is conventionally made of glues to be spread in two superimposed layers) and to withstand both the considerable tangential forces and the relatively high temperatures that occur during the braking phase (there are local peaks of over 100°C). The second method provides optimum results but requires expensive moulds and production processes; its cost is justified only in the case of mass production (for instance, 100 000 pieces). The object of the present invention is to remedy the drawbacks of the prior art. The inventive step on which the present invention is based is that of mechanically connecting the disc to the disc support. The best method that has been discovered for this connection is to use pins with heads. The present invention is set out in further detail in the following description made with reference to the accompanying drawings, which are not be considered to be limiting, but merely illustrative. In these drawings: Fig. 1 is a diagrammatic sectional view of a tubular motor of the present invention; Fig. 2 shows an embodiment of a disc support of the present invention, and includes a front view, a side view partly in section and an axonometric view; Fig. 3 shows an embodiment of a disc of the present invention, and includes a global side view, a side view of a pin and an axonometric view; Fig. 4 shows the disc of Fig. 3 connected to the support of Fig. 2, and includes a side view partly in section and an axonometric view. In the embodiment of a tubular motor of the invention shown diagrammatically in Fig. 1, the tubular motor is shown overall by reference numeral 1, the casing of the tubular motor is shown by reference numeral 10, the output pin of the tubular motor is shown by reference numeral 11, an electric motor is shown by reference numeral 2, the shaft of the electric motor is shown by reference numeral 21, the disc support of the brake device is shown by reference numeral 3, the plate of the brake device is shown by reference numeral 4, the disc of the brake device is shown by reference numeral 5, an actuation sleeve of the plate 4 is shown by reference numeral 6, a reducing gear is shown by reference numeral 7 and an electric control unit of the tubular motor is shown by reference numeral 8. For clarity of illustration, many conventional components of a tubular motor, in particular the supply wires of the tubular motor and the connection wires of the unit 8, are not shown. The operation of a tubular motor of the type of Fig. 1 as regards braking is well known; a helical spring is mounted on the shaft 21 of the motor 2, between the body of the motor 2 and the plate 4, and exerts a resilient force on the plate 4, urging it against the disc 5. This spring cannot be seen in Fig. 1 as it is hidden within the sleeve 6. The sleeve 6 is made from magnetic material. The rotor of the motor 2 comprises a projection (facing to the right in Fig. 1) called a "flow deflector". When current is supplied to the motor 2, the flow deflector generates a magnetic field which acts on the sleeve 6 (which is made from magnetic material), exerting a magnetic force which attracts the sleeve 6 towards the motor 2. Consequently, if the motor is not being supplied, the plate 4 and the disc 5 are in contact through the action of the spring and the motor is braked; if the motor is being supplied, the plate 4 and the disc 5 are not in contact through the action of the flow deflector and the motor is not braked and may therefore freely rotate. The movement of the plate 4 and/or the disc 5 could also be obtained in other different ways. The present invention is fully independent of the manner in which this movement is obtained. The present invention is described below. The various Figures, in particular Fig. 1, may be consulted for a better understanding of the following description. The tubular motor of the present invention is used to move awnings, curtains and the like and is provided with a brake device comprising a disc, a disc support and a plate. The brake device is formed such that the disc and the plate are in contact when the brake device is actuated (i.e. is braking) and are not in contact when the brake device is not actuated (i.e. is not braking). The disc of the brake device is mechanically connected to the support. In this way, the connection between the disc and the support is extremely simple to produce and is extremely efficient. It should be noted that, in the embodiments of the drawings, the plate, the disc and its support comprise a central hole through which the shaft of the electric motor can pass and rotate. The best way of connecting the disc to the support is by means of pins. For correct balancing of the brake device at least two pins are needed; for correct connection, the pins need to be provided with heads (or, as an equivalent, bulges). Fig. 3 shows an embodiment of a disc provided with six equidistant pins. Alternative solutions could make provision, for instance, for a different (larger or smaller) number of equidistant pins. It will be appreciated that, in general, the pins may take many different forms and be disposed on the disc and/or the plate. The pins could also be connected and mechanically linked to one another. It is advantageous to produce the disc and the pins in one piece. In practice, the cost of production is small and the connection of the disc is better and more reliable. A simple and efficient way of producing the pins is to produce them by means of small cylinders connected on one side to the disc and on the other side to the respective heads. The pins of the embodiment of Fig. 3 are produced in this way. To facilitate the operation to connect the disc to the support, it may advantageously be provided for the head of the pin to have a cavity so that it can be crushed. In the simplest form, this cavity could be formed by a deep furrow on the head of the pin. It will be appreciated that it is useful to facilitate connection, but that it is also important to prevent the disc from disengaging too readily from the support. For that reason, a good compromise solution is to provide the cavity of the head of the pin in the form of a hole and preferably in the form of a hole coaxial with respect to the pin. The pins of the embodiment of Fig. 3 are produced in this way. The shape of the head of the pin may advantageously be such as to facilitate the connection operation and to impede the disengagement operation. The pins of the embodiment of Fig. 3 are formed in this way. With reference to the pin of Fig. 3, it can be seen that, on the left, the increase in diameter is abrupt (almost forming an abutment) and that, on the right, the decrease in diameter is gradual (almost forming a lip). The most typical material from which the disc is made is silicone rubber. This material is also very adapted to the pins and their heads as it is appropriately resilient. The most typical material from which the disc support is made is plastic. This material is also very adapted to the present invention as it is rigid enough to be able to anchor the heads of the pins. The plate may be made from plastics material or metal material, and is preferably surface treated so as to avoid sticking to the disc if the motor remains stationary for long periods (for instance, hours or days). The actuation sleeve of the plate is typically made from magnetic material to be able appropriately to cooperate with a flow deflector. It will be appreciated that the sleeve may be made from other materials if the movement of the plate is obtained in another way. If the pins are associated with the disc, the disc support will advantageously be provided with seats adapted to receive the pins and to retain them through the head. The support of the embodiment of Fig. 2 is formed in this way. In this case, these seats are advantageously provided with lips to facilitate the insertion of the pins and, possibly, the crushing of the heads. The support of the embodiment of Fig. 2 is formed in this way. As an alternative, it is possible to provide pins rigidly connected to the support, and seats in the disc adapted to receive the pins and to retain their heads. In this case, it is advisable to provide cavities in the disc to facilitate the widening of the seats when the heads are being inserted.

Claims

1. A tubular motor for the movement of awnings, curtains and the like, provided with a brake device comprising a disc, a disc support and a plate, the brake device being formed such that the disc and the plate are in contact when the brake device is actuated and are not in contact when the brake device is not actuated, characterised in that the disc is mechanically connected to the support.

2. A tubular motor according to claim 1, wherein the disc is connected to the support by means of at least two pins provided with heads.

3. A tubular motor according to claim 2, wherein the disc and the pins are made in one piece.

4. A tubular motor according to claim 3, wherein each pin comprises a small cylinder connected on one side to the disc and on the other side to the head.

5. A tubular motor according to claim 3 or 4, wherein the head of the pin has a cavity so that it can be crushed.

6. A tubular motor according to claim 5, wherein the cavity of the head of the pin is a hole which is preferably coaxial with respect to the pin.

7. A tubular motor according to any of the preceding claims, wherein the disc is made from silicone rubber.

8. A tubular motor according to any of the preceding claims, wherein the disc support is made from plastics material.

9. A tubular motor according to any of the preceding claims, wherein the plate is made from plastics material or metal material, and is preferably surface treated so as to avoid sticking to the disc.

10. A tubular motor according to any of claims 3 to 9, wherein the disc support comprises seats adapted to receive the pins and to retain them by their heads.

11. A tubular motor according to claim 10, wherein the seats are provided with lips to facilitate the insertion of the pins and, possibly, the crushing of the heads.