GB2178794A

GB2178794A - A driving device employed in a window regulator

Info

Publication number: GB2178794A
Application number: GB08614020A
Authority: GB
Inventors: Tetuo Kobayashi; Shoichi Hirai
Original assignee: Nippon Cable System Inc
Current assignee: Nippon Cable System Inc
Priority date: 1984-01-20
Filing date: 1986-06-10
Publication date: 1987-02-18
Also published as: GB2176836B; GB2178794B; DE3441790A1; GB2176836A; GB2153906B; DE3448351C2; FR2558514B1; IT8423469A1; DE3441790C2; FR2558514A1; GB8614019D0; IT8423469A0; GB2153906A; GB8614020D0; GB8428203D0; IT1196321B

Abstract

The device, which automatically regulates the tension of wires employed in a window regulator, comprises a drum (4) winding on and off the wires (32, 33) and rotatable within a housing (1, 2), and having first ratchet teeth (7), and a portion (9) for engaging a first wire end. A ratchet plate (5) is coaxial with the drum, and has second ratchet teeth (12) engaging the first ratchet teeth and a portion (14) engaging a second wire end. A spiral spring (19) has one end engaged with the ratchet plate and its other end engaged with the housing (2), and urges the ratchet plate so that the first and second ratchet teeth are moved relatively to take up wire slack. An elastic member (spring 25) axially urges the drum toward the ratchet plate and causes relative rotation between the drum and a handle (28) to facilitate tensioning. A handle shaft (3) rotates the drum via a member (22) whose notch (23) engages a drum projection (24) with some play in the rotational direction. The mechanism of the present invention can employ a spiral spring (19) having a larger diameter, and therefore, functions of regulating tension of wires and of balancing the force for raising with the force for lowering the glass operate smoothly. <IMAGE>

Description

1 GB 2 178 794 A 1

SPECIFICATION

A driving device employed in a window regulator The present invention relates to a driving device 70 employed in a window regulator (hereinafter re ferred to as "driving device"), and, more particu larly, to the driving device which can automatically eliminate looseness or permanent elongation of wires, and which can always maintain tension of wires in a suitable range.

Until now, a window regulator, in which flexible wires are employed as a power transmitting means, has been used in doors of a car, or the like.

For example, a window regulator shown in Figure 24 has been known. Namely, the window regulator comprises two wires 81, 82 being laid in the win dow regulator in tense condition; a driving device 84 having a drum 83, for winding the wires 81, 82 in the opposite directions, to which one end of each wire is connected; and a driven device 87 having a carrier plate 86, capable of sliding on a guide rail 85, to which the other end of each wire 81, 82 is connected. When the drum 93 is rotated in the direction of Arrow A or B, one of the wires 81, 82 is wound around the drum 83 and the other wire is unwound from the drum 83, and as a re sult, the carrier plate 86 moves in the direction of Arrow C or D.

However, elastic elongation and permanent elongation generally generate in the wires, such as stranded metallic wires, in the course of the operation. If permanent elongation and/or looseness generate in the wires, tension of the wires is lost and it is impossible for the driving device 84 to correctly transmit the operational force to the driven device 87.

Such looseness or permanent elongation of wires causes the following disadvantages: For ex- ample, a window glass shakes in the up-and-down directions due to vibration of a car, or the like; a crank lever shakes due to vibration of a car, or the like; the window glass is stained since greased wires come in touch with the window glass; and a whipping noise of wires is generated in the doors due to vibration of a car, or the like. Such disadvantages offend a driver, or the like. Further, loosed wires tend to come off from a guide member or a pulley for guiding wires, and tend to be damaged. Therefore, the window regulator be- 115 comes inoperable occasionally.

Therefore, hitherto there has been proposed various means for eliminating looseness or permanent elongation of wires in order to suitably regulate tension of wires.

For example, there has been a tension-regulating mechanism for extending the length of wire-path, by means of a spring urging an outer casing (concluit), capable of slidably guiding a wire, toward an associating member with which the outer casing is to associate at one end of the outer casing, or by means of a tension pulley. Further, Italian Patent No. 927,030 (corresponding to British Patent No. 1382330) discloses another mechanism which can eliminate looseness of wires by means of manually rotating a ratchet plate relatively to the drum. The ratchet plate is adjacent to a wire-winding drum having a ratchet teeth and engaging with an end of a wire.

However, as to the former mechanism, there is a problem that it is somewhat hard to operate the device, since the wire is always stretched strongly.

As to the latter mechanism, there are some prob lems that it is practically impossible to regulate tension of wires after the mechanism is installed in an inside of a door of a car, or the like.

For eliminate the above disadvantages, mecha nisms for automatically eliminating permanent elongation generated in the wires are discussed in USP 4,400,993 and USP 4,440,354.

The mechanisms basically comprise two divided drums, i.e. a first drum and a second drum having ratchet teeth 93, 94 at each facing side, as indi cated by two-dot chain line in Figure 24. The mechanisms can eliminate permanent elongation by means of relative rotation of the first drum 83a and the second drum 83b. However, the mechanism has no function of balancing between force for raising the window glass and force for lowering the window glass, and no function of reducing the force for raising the window glass, since a spiral spring is not employed. As to the mechanism, in spite of having the spiral spring, the size of the spiral spring is restricted by the size (the diameter and the depth) of the cavity dug in the second pulley. Accordingly, the spiral spring is not substantially employed in the latter mechanism, except a spiral spring of which diameter and width are small, i.e. the urging force of the spiral spring is weak. Namely, the relative rotation of the first pulley and the second pulley is caused by a torque of a crank lever, by a braking force, i.e. a frictional resistance which is applied to the second pulley when the first pulley is rotated, and by the urging force of the spiral spring. However, the frictional resistance is not a suitable element, since the frictional resistance depends upon various conditions, i.e. roughness of each contacting surface, pressure between the pulleys, existence of some adhesion on the sliding portions, and the like. Also, the frictional resistance changes due to abrasion generated in the course of operation. Therefore, a dispersion of tension values becomes broad occasionally. Further, labor of the operation is large in case of rotating the second pulley since the frictional resistance is applied to the second pulley not only in one direction but also in the opposite direction.

In order to solve the above problems, it is de- sired that the spiral spring having high urging force as much as possible is employed. Namely, if the urging force of such spiral spring rotates the ratchet teeth in the direction of idling movement, tension can be regulated more precisely, and the operational labor can be decreased, as compared with the case of the above frictional resistance.

"Idling movement" or "move idly" described in the specification means that, when a torque due to the relative rotation of a first ratchet teeth and a second ratchet teeth by means of rotating a crank 2 GB 2 178 794 A 2 lever generates, slant portions of the first ratchet teeth and the second ratchet teeth slip in the rotational direction with each other, and both ratchet teeth move axially in the opposed direction with each other, and at last the ratchet teeth engage again. Further, the conception of "idling movement" or "move idly" includes not only a case that one ratchet teeth moves in the axial direction and rotates around the axis, but also various cases, e.g.

the case that one ratchet teeth moves in the axial direction and the other ratchet teeth rotates around the axis, or the case that both of the ratchet teeth move axially so as to depart away with each other, and one or both ratchet teeth rotate around the axis in the opposite directions.

On the other hand, when the spiral spring is adapted to support weight of the window glass or to balance the force for raising the window glass with the force for lowering the window glass, the urging force for balancing is not sufficient, since the size of the spiral spring is restricted by the size of the cavity dug in the conventional second pulley. In this respect, it is desired that the urging force of the spiral spring is increased as much as possible. Particularly, it is desired that the diameter, in the state of setting, of the spiral spring is large as much as possible in order to thin the whole thickness of the mechanism.

However, it is desired to reduce the operational force of the crank lever by means of increasing a ratio of a length of the crank lever to the diameter of the second pulley, i.e. by means of decreasing the diameter of the pulley. In order to satisfy the contradictory demands at the same time, it is thinkable to take out the spiral spring from the cav- 100 ity of the second pulley, and to locate at another portion. However, in that case, there happens a problem that the whole thickness of the driving device increases.

Further, in case that the above-mentioned mechanisms having rathcet teeth are employed in the driving device, excess elastic elongation is generated occasionally. For example, when sliding resistance between the carrier plate 86 and the guide rail 85 increases temporarily, or when the crank lever 91 is rotated in the direction of Arrow B after the first wire 81 has entirely wound up, (i.e. after the carrier plate 86 reaches the stopper 88), the relative rotation of the first drum 83a and the second drum 83b is excessively performed. As a result, excessive elastic elongation generates in the first wire 81 (and the second wire 82). Further, as a result, the mesh of the ratchet teeth 93, 94 might advance in a state of eliminating suitable play. It is disadvantageous that such excessive elastic elongation of the wires causes permanent elongation, and causes the pulley 89 and rotational shafts of other connecting members to be bended, and causes the operation of the crank lever 91 to be heavy.

Also, in case that the crank lever 91 is rotated in the direction of Arrow A, one fact that the above sliding resistance increases, or another fact that the crank lever is rotated in the direction of Arrow A after the carrier plate 86 has reached the oppo- site stopper 90 causes the ratchet teeth 93, 94 to fly over with each other, in spite of meshing direction of both ratchet teeth (this phenomenon is hereinafter referred to as "flying phenomenon").

The flying phenomenon causes wires to be loosed. By means of wearing out addendums of the ratchet teeth 93, 94, it tends to occur the flying phenomenon.

By the way, a mechanism for eliminating perma- nent elongation or looseness of wires, having a brake spring (e.g. a brake spring 114 in Figure 25) located between the driving shaft 95 and the drum 83, has been known.

The brake spring 114 shown in Figure 25 is employed to prevent a window glass (e.g. a window glass 100 of Figure 24) from being raised or lowered, except that the crank lever 113 or the shaft 112 is positively rotated. In such driving device, operations of the brake spring 114 are, as described later, realized by means of association of a notch portion 118 of a associating member 117 and a associating projection 119 of the drum 108 with some play, for example, an angle of 30 de grees, in the rotational direction. In that case, the drum 108 is not fixed to the shaft 112, and the as sociating member 117 is fixed to the shaft 112.

As shown in Figure 25, when the crank lever 113 is rotated in the direction of Arrow A, one side sur face 118a of the notch portion 118 pushes a nail 114a of the brake spring 114 in the direction of Ar row A. Accordingly, the locking operation of the brake spring (due to the frictional resistance of the brake spring and an inner peripheral surface of the housing) is released, since the diameter of the brake spring 114 is reduced. Accordingly, since the rotation of the associating memeber 117 causes the notch portion 118 and the associating projec tion 119 to associate with each other, the drum 108 can be rotated in the direction of Arrow A.

A rotation of the crank lever 113 in the direction of Arrow B also causes the locking operation of the brake spring to be unlocked.

Even if one tries to raise or lower the window glass 100 (see Figure 24) without rotating the crank lever 113, the brake spring 114 performs the lock ing operation, since the diameter of the brake spring 114 increases, and the associating projec tion 119 of the drum 108 pushes the nail 114a or 114b of the brake spring 114.

As described above, as to the locking operation or the unlocking operation, it is necessary for one nail to move to some extent before the other nail moves for the purpose of increasing or decreasing the diameter of the brake spring. For the purpose, it is necessary to have some play between the associating projection 119 and the notch portion 118 in the rotational direction. If there is no play between them, both of the nails 114a, 114b are rotated at the same time, namely the diameter of the brake spring 114 cannot be increased or decreased. Accordingly, the locking operation and the unlocking operation do not operate.

Accordingly, the shaft 112 is rotatable in the range of the play against the housing 111 without rotating the drum 108 itself. In that case, the crank 3 GB 2 178 794 A 3 lever 113 fixed to the end of the shaft 112 is also shakable by an angle of about 30 degrees.

Thus, when the window regulator is installed in a car, or the like, there is a problem that the crank lever 113 shakes or makes a noise due to vibration of a car, or the like. The problem causes a driver to feel some displeasure.

Further, the shaking of the crank lever 113 causes the nails 114a, 114b of the brake spring 114 to repeatedly receive impulse force. There is another problem that the repeated impulse force causes the nails 114a, 114b to sustain a damage of fatigue. Therefore, the operation of the window regulator cannot be performed.

As a method for solving the above problems, it 80 is thinkable to increase a frictional resistance of the shaft 112 and the housing 111 or a frictional resist ance of the shaft 112 and the drum 108, but it is difficult to maintain the frictional resistance in a suitable range, and it is not useful to increase the 85 frictional resistance because of making operational force to be heavy, and further, because of wearing out the sliding portion.

A main object of the present invention is to pro vide a driving device employed in a window regu- 90 lator which can surely prevent a crank lever from shaking.

Another object of the present invention is to pro vide a driving device employed in a window regu lator which can always maintain tension of wires in 95 a suitable range.

Another object of the invention is to provide a mechanism which can satisfy the contradictory de mands, i.e. employing a spiral spring having a larger diameter, increasing the ratio of the length of the crank lever to the diameter of the pulley (hereinafter referred to as "lever ratio"), and reduc ing the thickness of the mechanism, and whereby the function of regulating tension of wires and the function of balancing the force for raising the win dow glass with the force for lowering the window glass operate smoothly.

In accordance with the invention, there can be provided a driving device employed in a window regulator comprising:

(a) a housing; (b) a drum being provided for rotational move ment within the housing, and having a first side surface provided with a first ratchet teeth, a second side surface provided with a first engaging portion 115 for engaging a first wire end and a peripheral sur face as a wire-winding surface; (c) a ratchet plate being adjacent to the drum coaxially, and having a surface provided with a second ratchet teeth engaging the first ratchet 120 teeth of the drum and a second engaging portion for engaging a second wire end; (d) a spiral having one end engaged with the ratchet plate and having the other end engaged 6C with the housing, and urging the ratchet plate in such direction that the first ratchet teeth and the second ratchet teeth are moved idly; (e) an elastic member axially uring the drum to ward the ratchet plate; and (f) a shaft for rotating the drum by means of en- 130 gaging with the drum. Further, in accordance with the present invention, there can be provided a driving device employed in a window regulator comprising: 70 (a) a housing; (b) a driving member including a shaft provided for rotational movement within the housing and an associating member being fixed to the shaft, the associating member extending from the shaft in the radial direction and having at least one notch portion along a peripheral edge of the associating member; (c) a drum being provided within the housing, being adjacent to the associating member, being coaxial with the shaft, being rotatable around the shaft, and having an associating projection, the associating projection being mounted on a first side surface of the drum facing to the associating member, and being capable of associating with the notch portion with some play in the rotational direction; and (d) an elastic member urging the associating member in the rotational direction, by means of engaging one end of the elastic member with the drum and by means of engaging the other end of the elastic member with the driving member. Further, in accordance with the present invention, there can be provided a driving device employed in a window regulator comprising: (a) a housing; (b) a driving member including a shaft provided for rotational movement within the housing and an associating member, being fixed to the shaft, the associating member extending from the shaft in the radial direction and having at least a notch portion along a peripheral edge of the associating member; (c) a drum being provided within the housing, being adjacent to the associating member, being coaxial with the shaft, being rotatable around the shaft, being axially movable along the shaft, and having an associating projection, the associating projection being mounted on a first side surface of the drum facing to the associating member, being capable of associating with the notch portion with some play in the rotational direction, and having a first ratchet teeth on a second side surface of the drum opposite to said first side surface of the drum; (d) a ratchet member being provided within the housing adjacent to the drum, being coaxial with the shaft, being rotatable around the shaft, and having a second ratchet teeth on a first side surface of the ratchet member facing to the drum, the second ratchet teeth being capable of being meshed with the first ratchet teeth; (e) a spiral spring being located between the ratchet member and the housing so as to urge the ratchet member in the direction of idling move- ment of the first ratchet teeth and the second ratchet teeth; (f) an elastic member located between the drum and the associating member so as to urge the associating member in the rotational direction; (g) a first wire having an end engaged with the 4 GB 2 178 794 A drum and a second wire having an end engaged with the ratchet member; and (h) a first pushing projection and a second push ing projection being mounted on both low sides of the associating projection and being capable of being inserted between bottom surfaces of the as sociating member and the first side surface of the drum, respectively. Whereby, looseness and per manent elongation can be eliminated, tension of the wires is maintained in a suitable range because flying phenomenon is inhibited, and the shaking of a crank lever is surely avoided.

The above and other objects and advantages of the present invention will become apparent from the following description with reference to the ac companying drawings.

Figure 1 is a partially cutaway perspective view showing an embodiment of the driving device of the invention; Figure 2 is an exploded view in perspective of 85 the embodiment of the driving device of the inven tion shown in Figure 1; Figure 3 is a front view showing a window regu lator having the driving device of the invention; Figure 4 is a perspective view showing another embodiment of a drum in the driving device of the invention; Figure 5 is a perspective view showing another embodiment of a ratchet plate in the driving device of the invention; Figure 6 is a partially cutaway side view of an other embodiment of the driving device of the in vention; Figure 7 is a perspective view showing further another embodiment of the driving device of the 100 invention; Figure 8 is an exploded view in perspective of the embodiment of the driving device of the inven tion shown in Figure 7; Figure 9 - 14b are diagrams showing the opera- 105 tive states of the driving device of the invention shown in Figure 7; Figure 15 is an exploded view in perspective of another embodiment of the driving device of the invention; Figure 16 is a partially cutaway side view of an other embodiment of the driving device of the in vention; Figure 17 and Figure 18 are front views of a win dow regulator employing the driving device of the 115 invention; Figure 19 is a partially cutaway perspective view showing further another embodiment of the driv ing device of the invention; Figure 20 is a partial front view of the driving de, vice of the invention shown in Figure 19; Figure 21 is a partially cutaway side view of the driving device of the invention shown in Figure 19; Figure 22 and Figure 23 are a partial front view and a partially cutaway side view, respectively, showing operative states of the driving device of the invention shown in Figure 19; Figure 24 is a perspective view showing a win dow regulator of the prior art; and

Figure 25 is an exploded view in perspective of a 130 4 driving device of the prior art.

In Figure 1 and Figure 2, numerals 1, 2 indicate a first housing and a second housing, respectively. A. housing consists of the first housing 1 and the see- ond housing 2. The housing contains and supports a rotatable shaft 3. A drum 4 and a ratchet plate 5 are rotatably mounted on the shaft 3 and are adjacent to each other. The drum 4 is capable of moving in the axial direction on the shaft 3.

A first side surface 6 of the drum 4 is provided with a first ratchet teeth 7. A second side surface 8, which is an opposite surface to the first side surface 6, is provided with a first engaging portion 10 with which a first wire end 9 is engaged. A first side surface 11, adjacent to the drum 4, of the ratchet plate 5, is provided with a second ratchet teeth 12 capable of engaging with the first ratchet teeth 7 and a second engaging portion 14 with which a second wire end 13 is engaged, respectively.

On a second side surfece 15 of the ratchet plate 5, a boss 16, which is provided with a first engaging groove 17, is projected. Also, an inner peripheral surface of the second housing 2 is provided with a second engaging groove 18.

A spiral spring 19 is contained within the second housing 2. Both ends 20, 21 of the spiral spring 19 are inserted into the first engaging groove 17 and the second engaging groove 18, respectively. The spiral spring 19 urges the ratchet plate 5 in such direction that idling movement is generated, i.e. in the direction of Arrow A.

A cup-like associating member 22 is fixed to the shaft 3, and a fanshaped notch portion 23 is formed on the cylindrical side portion of the associating member 22. The second side surface 8 is provided with an associating projection 24 capable of associating with the fan-shaped notch portion 23 with some play in the rotational direction.

An elastic member, e.g. a coil spring 25, is located between the drum 4 and the associating member 22. The coil spring 25 urges axially the drum 4 toward the ratchet plate 5.

An end 26 of the shaft 3 projects from a perfora- tion 27 of the first housing 1, and a crank lever 28 is fixed to the end 26 of the shaft 3. A brake spring 29, which is known conventionally, is inserted be tween an inner peripheral surface of the first hous ing 1 and an outer peripheral surface of the associating member 22, and both ends 30, 31 of the brake spring 29 are inserted into gaps between the fan-shaped notch portion 23 and the associat ing projection 24, respectively.

A peripheral surface of the drum 4 is used as a wire-winding surface 36 for winding a first wire 32 and a second wire 33. The first wire 32 and the second wire 33 are wound in the same spiral direc tion (in case of Figure 2, in the spiral direction like a left handed screw), respectively. The first wire end 9 of the first wire 32 is engaged with the first engaging portion 10. The first wire 32 is spirally wound toward the first side surface 6 side, goes away from the drum 4 on its way, and is guided into a first outer casing 35 through a first guiding groove 34 of the second housing 2. The second GB 2 178 794 A 5 wire end 13 of the second wire 33 is engaged with the second engaging portion 14 of the ratchet plate 5. The second wire 33 is wound around the winding surface 36 from the first side surface 6 side to- ward the second side surface 8 side, goes away from the drum 4 on its way, and is guided into a second outer casing 38 through a second guiding groove 37. The other each end of the first wire 32 and the second wire 33 are engaged with a carrier plate 41 of a driven portion 40 of a window regulator 39, as described later. Accordingly, the first wire 32 and the second wire 33 form a closed loop substantially.

Hereinafter, the functions of the driving device of the invention will be described. In order to clearly describe the functions of the driving device, the driving device employed in the window regulator 39 shown in Figure 3 is described as a typical case. However, the use of the driving device of the in- vention is not limited to the typical case. Namely, the mechanism can be applied into various devices employing wires as power transmitting means.

In Figure 3, a numeral 42 indicates a driving portion of the window regulator 39. The driving por- tion 42 is connected to the dirven portion 40 by means of two control cables 43, 44. The driving de vice of the present invention is contained in the driving portion 42. The driven portion 40 has a guide rail 45 and a carrier plate 41 slidably mounted on the guide rail 45. In order to change the moving direction of the wires 32, 33, a wire guide (or a pulley) 46 is mounted on the upper end of the guide rail 45. Similarly, in order to change the moving direction of the wire 32, a pulley (or a wire guide) 47 is set to the lower end of the guide 100 rail 45.

The control cable 43 comprises a first wire 32 and a first outer casing 35 for slidably guiding the first wire 32, and similarly, the control cable 44 comprises a second wire 33 and a second outer casing 38. That is to say, the control cables 43, 44 are pull-control cables.

As to the window regulator 39 constructed as mentioned above, when the crank lever 28 is ro- tated in the direction of Arrow A, the second wire 33 is wound around the drum 4 and the first wire 32 is unwound from the drum 4. Therefore, the closed loop circulates in the direction of Arrow C, and a window glass G fixed to the carrier plate 41 is raised. In case that the crank lever 28 is rotated in the direction of Arrow A, the drum 4 and the ratchet plate 5 rotate together in the same direction, since the first ratchet teeth 7 and the second ratchet teeth 12 are firmly engaged with each other.

Further, when the crank lever 28 is rotated in the direction of Arrow B, the first wire 32 is wound around the drum 4 and the second wire 33 is unwound from the drum 4. Therefore, the closed loop circulates in the direction of Arrow D, and the win- 125 dow glass G is lowered. In that case, though the direction of Arrow B is the direction of idling movement, the drum 4 and the ratchet plate 5 ro tate together in the same direction, since the see ond wire 33 pulls the ratchet plate 5 to rotate, and130 since the coil spring 25 urges the drum toward the ratchet plate and causes the ratchet plate to be rotated in the direction of Arrow B. Since the length of the wound part of one wire around the drum 4 is equal to the length of the unwound part of the other wire from the drum 4 without reference to the rotational direction, the one wire is wound on the portion where the other wire is unwound, subsequently. Namely, the driving device of the invention has only one winding surface 36 instead of two winding surfaces for winding two wires. Therefore, the thickness of the drum 4 can be thinned. Accordingly, as mentioned later, even if a spiral spring 19 having a large di- ameter in a state of setting and the drum 4 are axially formed in a row, the whole thickness of the mechanism can be thinned.

Subsequently, the function of automatically eliminating looseness of the wires 32, 33 will be de- scribed.

In case that looseness is generated in the wires, when the drum 4 is rotated in the direction of Arrow B by means of rotating the crank lever 28 in the direction of Arrow B, the second wire 33 does not pull theratchet plate 5 in the direction of Arrow B. Further, the ratchet plate 5 is in a state of being braked by the urging force of the spiral spring 19 in the direction of Arrow A and further by, for instance, frictional resistance between the rachet plate 5 and the shaft 3. Therefore, the drum 4, receiving torque in the direction of Arrow B, moves toward the second side surface 8 in the axial direction against the urging force of the coil spring 25. The first ratchet teeth 7 climbs over the second ratchet teeth 12, and at last the first ratchet teeth 7 and the second ratchet teeth 12 engage with each other again at the new shifted position by means of the urging force of the coil spring 25. Namely, idling movement occurs. Accordingly, only the drum 4 rotates in the direction of Arrow B, so that the relative rotation of the drum 4 and the ratchet plate 5 is performed. Therefore, the second wire 33 slides on the winding surface 36 of the drum 4, and is pulled out toward the second en- gaging portion 14 side. As a result, looseness of the wires is eliminated.

After tension of the wires is recovered, the ratchet plate 5 and the drum 4 are rotated together again.

As to the driving device of the invention, in case that the urging force of the spiral spring 19 is stronger than the required force for making the first ratchet teeth 7 and the second ratchet teeth 12 to move idly (the required force also depends upon the urging force of the coil spring 19, and the inclination angle of each tooth of the ratchet teeth 7, 12), as mentioned later, the spiral spring 19 drives the ratchet plate 5 to rotate positively in the direction of Arrow A, as well as the spiral spring 19 gives the braking force to the ratchet plate 5. Therefore, tension of wires are regulated more accurately. In that case, the crank lever 28 can be stayed still.

Namely, when looseness is generated in the wires, the ratchet plate 5, which is urged by the 6 GB 2 178 794 A 6 spiral spring 19 in the direction of Arrow A, is ro tated in the direction of Arrow A due to idling movement. As a result, the second wire end 13 is pulled in the direction of Arrow A, the second wire 33 is pulled out of the winding surface 36 of the drum 4, and at last the first ratchet teeth 7 and the second ratchet teeth 12 are engaged with each other by means of the coil spring 25 at the position that tension of the wires is in proportion to the urging force of the coil spring 25. Accordingly, since looseness of the wires is eliminated, the suit able tension of the wire is recovered. When only the ratchet plate 5 is rotated by the spiral spring 19, the drum 4 is braked by the urging force of the brake spring 29, or by the frictional force between the drum 4 and the shaft 3.

In case that the crank lever 28 is stayed still, the operation of eliminating looseness of the wires tends to be obtained in the state that the drum 4 is sufficiently rotated in the direction of Arrow B. This 85 is based on reasons that the urging force of the spiral spring 19 is increased in proportion to the amount of winding of the spiral spring, and further the amount of winding of the second wire 33 around the drum 4 is small in the state mentioned 90 above.

In case that the driving portion 42 having the driving device of the invention is connected to the driven portion 40, so that Such direction that the spiral spring 19 urges the ratchet plate 5 corre sponds to such direction that the window glass G is raised, the spiral spring 19 functions as a known balance spring.

Namely, since the spiral spring 19 always urges the closed loop of the wires in the direction of Ar row C shown in Figure 3, the weight of the window glass G is balanced with the urging force of the spiral spring 19. Therefore, the operational force of the crank lever 28 has nothing to do with the rota tional directions of the crank [ever 28, and the op eration is made easy. Further, the labor to raise the window glass G is reduced. In that case, when the window glass is lowered, the spiral spring 19 is fastened. On the other hand, when the window glass is raised, the spiral spring 19 is loosed.

In the driving device of the invention, the spiral spring 19 is located in a series state with the drum 4 and the ratchet plate 5, without being contained in the drum 4. Therefore, the lever ratio can be in creased by means of reducing the diameter of the drum 4. Further, the function of balancing is made good by means of adapting the spiral spring which has a large diameter in the state of setting. More further, the thickness of the drum 4 can be thinned, i.e. the whole thickness of the driving device can be thinned, since the drum 4 serves as both wind ing drums for the first wire 32 and the second wire 33.

Since the diameter of the spiral spring 19 is not limited by the diameter of the drum 4, the diame ter of the spiral spring 19, in the state of setting, can be made larger than the diameter of the drum 4. Therefore, the spiral spring having a strong urg ing force can be employed.

In that case, as shown in Figures 1 and 2, if the 130 housing consists of two divided housings, i.e. the first housing 1 for containing the drum 4 and the second housing 2 for containing the spiral spring 19, it is easy to assemble the driving device. The ratchet plate 5 can be contained in the second housing 2. Further, as shown in Figure 6, the ratchet plate 5 can be contained in the first housing 1.

In the driving device shown in Figures 1 and 2, the second engaging portion 14 is located outside the second ratchet teeth 12, but is is desired to make the second engaging portion 14 to approach the center of the rotation so as to effectively utilize the urging force of the spiral spring 19.

Referring to Figures 4 to 6, such preferred embodiment of the driving device of the invention will be described.

In the drum 51 shown in Figure 4, a part 52 of the winding surface adjacent to the first side surface extends to the inside of the first ratchet teeth 7. In that case, even if the first ratchet teeth 7 is destroyed partially, i.e. the first ratchet teeth is not a complete ringshaped ratchet teeth, the function of the first ratchet teeth can be maintained.

In Figure 5, the ratchet plate 53 which is associated with the drum 51 in Figure 4 is shown. In that case, the second engaging portion 54 is located inside the second ratchet teeth 12.

Further, as shown in Figure 5, when a guide sur- face 55 is formed as the extending portion of the second engaging portion 54, the guide surface 55 can guide a portion adjacent to the wire end advantageously.

In the mechanism shown in Figure 6, a drum 56 is provided with a cylindrical groove 57 concentrically. Further, the drum 56 has a guide channel (not shown in the drawing) which is similar to the part 52 (shown in Figure 4). The ratchet plate 58 is provided with a cylindrical projection 59 which is engaged in the cylindrical groove 57. The cylindrical projection 59 is provided with a second engaging portion 60. An outer peripheral surface 61 of the cylindrical projection 59 is formed as a wirewinding surface.

According to the above mechanism, a part of wire can be wound on the outer peripheral surface 61 of the cylindrical projection 59 continuously, due to the motion that the drum 56 and the ratchet plate 58 rotate in the reverse direction with each other. Accordingly, even in case that the extents of looseness or permanent elongation of wires are greatly increased, the mechanism can be sufficiently applied to.

In the above mentioned embodiments, it is de- sired that the winding surface of the drum is provided with a spiral winding groove (for example, the portion indicated as a numeral 62 in Figure 4), so that the wires are wound in order without being intertwisted with each other.

With respect to the driving device of the invention, when the second engaging portion 14 is higher than the second ratchet teeth 12 in the axial direction, the second wire 33 does not preferably interfere with the ratchet teeth 7, 12. Such preferable embodiment can be realized, for example, by 7 GB 2 178 794 A 7 means of projecting the second engaging portion 14 from the surface of the ratchet plate 5 as shown in Figure 2 or Figure 5, or by means of forming the second engaging portion 60 within the cylindrical projection 59 as shown in Figure 6. In that case, such part of the winding groove 62, which is nearest to the first side portion 6, is formed into a circular groove instead of a spiral groove.

As mentioned above, according to the invention, the spiral spring having a larger diameter, and therefore, having a stronger urging force can be employed; the lever ratio can be increased; the thickness of the driving device can be made thin; and therefore, the function of regulating tension of wires and the function of balancing force for raising a window glass with force for lowering the window glass can operate smoothly.

Figures 7 and 8 show an embodiment of the driving device of the invention similar to the driv- ing device shown in Figures 1 and 2. Therefore, as to the same part shown in Figures 1 and 2, the same numerals are used and detailed descriptions are omitted.

In Figures 7 and 8, a cup-like associating mem- ber 22 is fixed to the shaft 3, and a fan-shaped notch portion 23 is formed on the cylindrical side portion of the associating member 22. A driving member consists of the shaft 3 and the associating member 22. The second side surface 8 of the drum 4 is provided with a associating projection 24 capable of associating with the notch portion 23 of the associating member 22 with some play in the rotational direction.

A coil spring 25 is located between the drum 4 and the associating member 22 as an elastic mem- ber. The coil spring is provided with bended end portions 25a, 25b. One end portion 25a is engaged with the associating member 22 and the other end portion 25b is engaged with the drum 4.

The coil spring 25 urges the drum 4 which is axi ally movable along the shaft 3 toward the ratchet plate 5 side, and further urges the drum 4 in the direction of Arrow B, i.e. in the rotational direction of idling movement.

Both low sides of the associating projection 24 110 are provided with a first pushing projection 65 and a second pushing projection 66 (shown in Figure 8).

The first pushing projection 65 is located on the side portion where the rotation of the associating member 22 in the direction of meshing of the ratchet teeth 7, 12 causes the notch portion 23 to push the associating projection 24. An upper portion (indicated as 65a in Figure 14a) of the first pushing projection 65 is preferably tapered, so that it is easy for the first pushing projection 65 to slide into a gap between the bottom surface 22a (see Figure 12) of the associating member 22 and the second side surface 8 of the drum 4, i.e. it is easy for the drum 4 to axially move toward the ratchet plate 5. Whereby, the later described operation of eliminating looseness of wires is made easy. When the notch portion 23 associates with the associating projection 24 due to rotation of the crank lever 28, there generates an axial force in the direction of Arrow Q, so that a pushing force of the drum 4 toward the ratchet plate 5 is increased, and therefore, the mesh of the ratchet teeth 7, 12 is more ensured. Accordingly, the flying phenomenon is more effectively inhibited.

Also, the second pushing projection 66 is preferably provided with a small tapered portion or a small round portion 66a (see Figure 14), so that insertion or removal of the second pushing projec- tion 66 into or from a gap between the bottom surface 22a and the second side surface 8 is made smooth.

The shapes and the numbers of the first pushing projection 65 and the second pushing projection 66 are not limited. For example, as shown in Figure 15, two first pushing projections and two second pushing projections can be arranged on a circular line, respectively. In that case, the associating member 22 can be provided with a notch portion 23a which is located in the opposite side of the notch portion 23 and which is provided to a portion corresponding to pushing projections 65, 66. Generally, it is sufficient to provide with one first pushing projection 65 and one second pushing projection 66 on the circular line.

Also, a few number of associating projections can be mounted on the drum, and in that case, the associating member is provided with notch portions of which number is corresponding to that of the associating member.

As shown in Figure 8, an end 26 of the shaft 3 is inserted into a perforation 27 of the first housing 1, and a crank lever 28 is fixed to the end 26. Further, a conventional brake spring 32 is set between an outer periphral surface of the associating member 22 and an inner periphral surface of the first housing 1, and both ends 30, 31 of the brake spring 29 are inserted into gaps existing between the notch portion 23 and the associating projection 24, re- spectively.

As shown in Figure 9 and Figure 10, in case that the crank lever 28 is not given a torque, the side surface of the notch portion 23 is in contact with the side surface of the associating projection 24. The former urges the latter. Further, it is not easy to rotate the drum 4 itself because of receiving the tension of the wires 32, 32. Therefore, the shaking of the crank lever 28 does not occur.

During the crank lever 31 is rotated in the direc- tion of Arrow A or in the direction of Arrow B, the first pushing projection 65 or the second pushing projection 66 is in the state of being inserted between the bottom surface 22a or 22b of the associating member 22 and the second side surface 8 of the drum 4 (as shown in Figure 14a and Figure 14b). As a result, the drum 4 cannot move toward the associating member 22 side on the shaft 3, and the drum 4 is pushed toward the ratchet plate 5. Accordingly, the flying phenomenon of the ratchet teeth 7, 12 is avoided and excessive elasitic elongation due to idling movement does not occur in the wires 37, 38.

in the driving device of the invention, looseness of each wire 32, 33 is eliminated, as described later.

8 GB 2 178 794 A 8 When the crank lever 28 is rotated in the direction of Arrow B, the side surface of the notch portion 23 is in contact with the side surface of the associating projection 24 in the state shown in Figure 13 and Figure 14. Then, when the crank lever 28 becomes free from one's hand at the same time when the rotation of the crank lever 28 is stopped, the crank lever 28 rotates in the direction of Arrow A shown in Figure 8 due to the urging force of the coil spring 25, and returns to the state shown in Figure 9 and Figure 10 through the state shown in Figure 11 and Figure 12. In the state shown in Figure 11 and Figure 12, neither the first pushing projection 65 nor the second pushing projection 66 is inserted between the bottom surface 22a or 22b of the associating member 22 and the second side surface 8 of the drum 4. Therefore, the drum 4 can move in the direction of Arrow P by a gap h. Accordingly, looseness or permanent elongation gen- erated in the wires 32, 33 is easily eliminated owing to idling movement of the ratchet teeth 7, 12 by menas of the operation of the spiral spring 19, on the way from the state shown in Figure 13 and Figure 14 to the state shown in Figure 9 or Figure 10.

As a torque generating means between the drum 4 and ratchet plate 5 in order to generate idling movement, for example, a spiral spring 19 shown in Figure 8 can be preferably employed.

As shown in Figure 8, the spiral spring 19 having one end 20 inserted into the first engaging groove 17 of the boss 16 of the ratchet plate 5 and having the other end 21 inserted into the second engaging groove 18 of the inner peripheral surface of the second housing 2 is preferably employed, since the size of the spiral spring 19 is not limited by the size of the drum 4.

The ratchet member in the present invention is not limited to the ratchet plate 5. As shown in Fig- ure 15, as a ratchet member, a ratchet drum 4a, with its configuration similar to the drum 4, capable of winding the second wire 33 around the outer peripheral surface can be employed.

Further, as shown in Figure 16, a ratchet plate 5 having a small cylindrical projection 5b which is contained within the drum 4 and which is capable of winding an end portion of the second wire around the peripheral surface thereof, can be employed as a ratchet member.

Though the direction of the relative torque of the drum and the associating member 22 owing to the elastic member (e.g. the coil spring 25 shown in Figure 10) is not limited, the direction of the torque owing to the elastic member is preferably the di- rection in which the drum 4 is rotated in the direction of meshing the ratchet teeth 7 with the ratchet teeth 12 as shown in Figure 8 or Figures 9 to 14. Whereby, just after the crank lever 28 is rotated in the direction of idling movement of the ratchet teeth 7, 12, the associating member 22 is rotated by the coil spring 25. Therefore, looseness and permanent elongation of the wires can be smoothly eliminated. be employed not only in the window regulator having inverse-J shape as shown in Figure 3, but also another type of window regulators, for example, shown in Figures 17 and 18.

In the window regulator shown in Figure 17, a driving device 48 and a guide rail 45 are separately mounted on a door of an automobile, or the like. Between the driving device 48 and the guide rail 45, wires 32, 33 are stretched in a triangular form.

In the window regulator of Figure 18, there are employed two wires 32, 33 which are slidably guided by outer casings 35, 38 and are arranged in a triangular form.

In Figure 19, numerals 1, 2 indicate a first housing and a second housing, respectively. A housing consists of the first housing 1 and the second housing 2. The housing contains and supports a rotatable driving member 70. The driving member 70 consists of a shaft 3 and a cup-like associating member 22 radially extending from the shaft 3. The associating member 22, for example, can be fixed to the shaft by means of welding. The associating member 22 is provided with a fan-shaped notch portion 23 along the cylindrical peripheral portion thereof.

A drum 4 is rotatably mounted on the shaft 3 for winding up wires 32, 33. The drum 4 is adjacent to the associating member 22. The drum 4 is provided with an associating projection 24 capable of associating with the notch portion 23 of the associating member 22 with some play in the rotational direction. The associating projection 24 has a fanshaped cross section.

As shown in Figure 22, a center portion of the drum 4 is provided with a first bore 71 capable of being directly in contact with the shaft 3 and a sec- ond bore 72 having a diameter which is larger than the diameter of the shaft 3. The second bore 72 is coaxial with the first bore 71. Insertion of the shaft 3 into the bores 71, 72 of the drum 4 makes a cylindrical space 73 to be formed. A coil spring 25 is set in the cylindrical space 73, and both ends 25a, 25b of the coil spring 25 are engaged with the associating member 22 and the drum 4, respectively. In that case, the coil spring 25 is given torsional deflection, so that the coil spring 25 urges the drum 4 in the direction of Arrow B, i.e. in the direction of idling movement of the ratchet teeth 7, 12.

Further, the coil spring 25 preferably urges the drum 4, which is movable in the axial direction, toward the ratchet plate 5.

Further, in Figure 19, numeral 7 indicates a first ratchet teeth formed on the other surface side of the drum 4, and numeral 5 indicates a ratchet plate having a second ratchet teeth 12 capable of meshing with the first ratchet teeth 7. The ratchet plate 5 is urged in such direction that idling movement occurs between the first and second ratchet teeth 7, 12, i.e. in the direction of Arrow A in Figure 19. The spiral spring 19 has an end engaged with the second housing 2 and the other end engaged with a boss 16 of the ratchet plate 5.

The ratchet plate is provided with an engaging portion 14 capable of engaging a wire end 13 of a second wire 33. A wire end 9 of a first wire 32 is engaged with an engaging portion 10 provided in the drum 4.

9 GB 2 178 794 A 9 The ratchet plate 5, the first and second ratchet teeth 7, 12 and the spiral spring 19 make a wire tension-adjusting mechanism. The ratchet plate 5 and the second housing 2 make a compartment for 5 containing the spiral spring 19.

If the crank lever 28 shown in Figure 19 do not receive a rotational torque, the associating member 22 is urged in the direction of Arrow A by means of the coil spring 25 as shown in Figures 20 and 21. Therefore, one side surface 23a of the notch portion 23 always urges a side surface 24a of the associating projection 24 facing to the one side surface 23a. The drum 4 itself is hardly rotatable, since the drum 4 is connected to the window glass (for example, indicated as 100 in Figure 24) through the wires 32, 33.

Accordingly, the shaft 3 and the crank lever 28 do not rotate against the drum 4. Whereby, the shaking of the crank lever 38 is avoided.

When the crank lever 28, as shown in Figure 19, is rotated in the direction of Arrow B, the associating member 22 rotates against the urging force of the coil spring 25 in the range of the play with the drum 4 being stationary. Then, the other side sur- face 23b of the notch portion 23 pushes the other side surface of the associating projection 24. As a result, the drum 4 can rotate. When the rotational operation is finished, the associating member 22 returns in the state shown in Figure 20 and Figure 21.

When the crank lever 28 shown in Figure 19 is rotated in the direction of Arrow A from the state shown in Figure 20 and Figure 21, the drum is di rectly rotated in the direction of Arrow A, since the one side surface 23a of the associating member 23 100 is previously in contact with the one side surface 24a of the associating projection 24. In the driving device of the invention, one nail 31 of the brake spring 29 is set between the one side surface 23a of the notch portion 23 and the one side surface 105 24a of the associating projection 24 with no play in the state shown in Figure 20 and Figure 21. On the other hand, there is some play between the other side surface 23b of the notch portion 23 and the other side surface of the associating projection 24.110 Accordingly, the unlocking operation and the locking operation can normally behave.

The coil spring employed in the driving device of the present invention can be employed to any driv- ing device having the drum and the driving member which are associated with each other with some play in the rotational direction. For example, the coil spring can be easily employed in a driving device of a prior art shown in Figure 25.

As to the driving device shown in Figure 25, the same spring as the coil spring shown in Figure 19 can be set between a drum 108a and an associating member 117.

In the driving devices provided with a mecha- nism capable of automatically regulating tension of 125 wires by means of ratchet teeth, such as the driving devices shown in Figure 19 or Figure 25, the coil spring 25 of the driving device of the present invention also behaves as an elastic member which urges axially one ratchet teeth toward the other ratchet teeth, so that both sets of ratchet teeth strongly mesh with each other. Accordingly, the coil spring 25 can be employed instead of a conventional waved washer 121 shown in Figure 25.

As described above, the mechanism for preventing the crank lever from shaking can be employed in various wire-driving devices or various window regulators, for example, the window regulators shown in Figures 17 and 18.

As described above, the driving device of the invention has effects that looseness and permanent elongation of the wire can be eliminated, that tension of the wires is maintained in a suitable range because flying phenomenon is inhibited, and that the shaking of a crank lever is surely avoided.

Though several embodiments of the invention are described in detail, it is to be understood that the present invention is not limited to the above embodiments, and various changes and modifications may be made in the invention without departing the spirit and the scope thereof.

Claims

1. A driving device capable of being employed in a window regulator comprising:

(a) a housing; (b) a drum being provided for rotational movement within said housing, and having a first side surface provided with a first ratchet teeth, a second side surface provided with a first engaging portion for engaging a first wire end, and a peripheral surface as a winding surface.

(c) a ratchet plate being adjacent to said drum coaxially, and having a surface provided with a second ratchet teeth engaging said first ratchet teeth of said drum and a second engaging portion for engaging a second wire end; (d) a spiral spring having one end engaged with said ratchet plate and having the other end engaged with said housing, and urging said ratchet plate in such direction that said first ratchet teeth and said second ratchet teeth are moved idly; (e) an elastic member axially urging said drum toward said ratchet plate; and (f) a shaft for rotating said drum by means of engaging with said drum.

2. The driving device of Claim 1, wherein said urging direction of said spiral spring corresponds to a direction of raising a window glass.

3. A driving device employed in a window regulator as claimed in claim 1 substantially as described with reference to the accompanying drawings.

Printed for Her Majesty's Stationery Office by Croydon Printing Company (UK) Ltd, 12/86, D8817356. Published byThe PatentOffice, 25 Southampton Buildings, London,WC2A1AY, from which copies may be obtained.

3. The driving device of Claim 1, wherein urging torque of said spiral spring is larger than torque of idling movement of said first ratchet teeth and said second ratchet teeth.

4. The driving device of Claim 1, wherein said second engaging portion of said ratchet plate is located outside said second ratchet teeth in the radial direction.

5. The driving device of Claim 1, wherein said second engaging portion of said ratchet plate is located inside said second ratchet teeth in the radial direction.

6. The driving device of Claim 5, wherein said first side surface of said drum has a cylindrical GB 2 178 794 A groove around the axis of said drum having a spiral winding groove extending from said peripheral surface of said drum adjacent to said first side surface toward said cylindrical groove, said ratchet plate has a cylindrical projection capable of being inserted in said cylindrical groove, said cylindrical projection has said second engaging portion, and a winding surface is mounted on a peripheral sur face of said cylindrical projection.

7. The driving device of Claim 1, wherein a di- 75 ameter of said spiral spring in a state of setting in said housing is larger than a diameter of said drum.

8. A driving device employed in a window reg- ulator comprising:

(a) a housing; (b) a driving member including a shaft provided for rotational movement within said.housing and an associating member, being fixed to said shaft, said associating member extending from said shaft in the radial direction and having at least a notch portion along a peripheral edge of said associating member; (c) a drum being provided within said housing, being adjacent to said associating member, being coaxial with said shaft, being rotatable around said shaft, being axially movable along said shaft, and having an associating projection, said associating projection being mounted on a first side surface of said drum facing to said associating member, being capable of associating with said notch por tion with some play in the rotational direction, and having a first ratchet teeth on a second side sur face of said drum opposite to said first side surface of said drum; (d) a ratchet member being provided within said housing, being adjacent to said drum, being coax ial with said shaft, being rotatable around said shaft, and having a second ratchet teeth on a first side surface of said ratchet member facing to said drum, said second ratchet teeth being capable of being meshed with said first ratchet teeth; (e) a spiral spring located between said ratchet member and said housing and urging said ratchet member in the direction of idling movement of said first ratchet teeth and said second ratchet teeth; (f) an elastic member located between said drum and said associating member so as to urge said associating member in the rotational direction; (g) a first wire having an end engaged with said drum and a second wire having an end engaged with said ratchet member; and (h) a first pushing projection and a second push ing projection being mounted on both low sides of said associating projection, and being capable of being inserted between bottom surfaces of said as sociating member and said first side surface of the drum, respectively.

9. The driving device of Claim 8, wherein said 125 elastic member urges said drum and said associat ing member in the direction of idle movement of said both ratchet teeth.

10. The driving device of Claim 8, wherein said ratchet member is a ratchet plate.

11. The driving device of Claim 8, wherein said ratchet member is a ratchet drum capable of wind ing said second wire on a peripheral surface of said ratchet drum.

12. A driving device employed in a window regulator comprising:

(a) a housing; (b) a driving member including a shaft provided for rotational movement within said housing and an associating member being fixed to said shaft, said associating member extending from said shaft in the radial direction and having at least one notch portion along a peripheral edge of said asso ciating member; (c) a drum being provided within said housing, being adjacent to said associating member, being coaxial with said shaft, being rotatable around said shaft, and having an associating projection, said associating projection being mounted on a first side surface of said drum facing to said associating member, and being capable of associating said notch portion with some play in the rotational direction; and (d) an elastic member urging said associating member in the rotational direction, by means of engaging one end of said elastic member with said drum and by means of engaging the other end of said elastic member with said driving member.

13. The driving device of Claim 12, wherein said elastic means is a coil spring.

14. A driving device employed in a window regulator substantially as described with reference to Figures 1 and 2, Figure 5, Figure 6, Figures 7 and 8, Figure 15, Figure 16 or Figures 19, 20 and 21 of the accompanying drawings.

Amendments to the claims have been filed, and have the following effect:(b) New or textually amended claims have been filed as follows:- 1. A driving device employed in a window regulator comprising:

(a) a housing; (b) a driving member including a shaft provided for rotational movement within said housing and an associating member being fided to said shaft, said associating member extending from said shaft in the radial direction and having at least one notch portion along a peripheral edge of said asso- ciating member; (c) a drum being provided within said housing, being adjacent to said associating member, being coaxial with said shaft, being rotatable around said shaft, and having an associating projection, said associating projection being mounted on a first side surface of said drum facing to said associating member, and being capable of associating said notch portion with some play in the rotational direction; and (d) an elastic member urging said associating member in the rotational direction, by means of engaging one end of said elastic member with said drum and by means of engaging the other end of said elastic member with said driving member.

2. A driving device as claimed in claim 12,.

11 GB 2 178 794 A 11 wherein said elastic means is a coil spring.