GB2166532A

GB2166532A - Spin dryer

Info

Publication number: GB2166532A
Application number: GB08525349A
Authority: GB
Inventors: George Thomas Hudson; Timothy David Cock; David John Hulse
Original assignee: TI Creda Manufacturing Ltd
Current assignee: TI Creda Manufacturing Ltd
Priority date: 1984-10-17
Filing date: 1985-10-15
Publication date: 1986-05-08
Also published as: GB2166532B; GB8525349D0; GB8426171D0

Abstract

A spin dryer has an interlock mechanism (3) which prevents the lid (2) of the dryer from being opened until the speed of the drum has fallen to a safe level. The interlock mechanism (3) includes a catch (10) and a vane (14) which responds to the air flow generated by rotation of the drum of the dryer and holds the catch (10) in an interlocking position in which it engages the lid (2) of the dryer and prevents it from being opened. A bracket (20) may surround the vane (14) to prevent it from being struck by the rotating drum in the event of an imbalance condition within the drum. This bracket also serves to retard the drum in the event of an imbalance condition. <IMAGE>

Description

SPECIFICATION Interlock mechanism especially for laundry equipment The present invention relates to spin dryers and, more especially, to spin dryers suitable for domestic use.

The invention relates in particular to the locking arrangement provided for the closure member of the loading aperture of the dryer i.e. the aperture through which articles to be dried are loaded into the rotatable drum. This locking arrangement is required to prevent access to the drum until the latter has either ceased to rotate completely or its speed has, at least, dropped below a certain level.

It is customary to provide spin dryers with a main latch which, in addition to holding the lid of the dryer in a closed position also controls operation of the motor that rotates the drum of the dryer. The motor is arranged to operate as the lid is closed and remains in operation for as long as the main latch is secured, while release of the latch automatically cuts off the supply of power to the motor. An interlock mechanism is provided to ensure that, even though the main latch has been released, the lid of the dryer can not then be opened immediately because the drum of the dryer will still be moving at high speed.

Interlock mechanism are known which prevent the lid of a spin dryer from being opened for a predetermined time after the motor has been switched off. These suffer from the disadvantage that, if the predetermined time is too short, the lid can be opened while the drum is still rotating whereas, if the predetermined time is too long, it is an annoyance to the user. In view of this, interlock arrangements have been proposed which respond to motion of the drum and remain actuated only until the drum has come substantially to rest or its speed has dropped below a certain level and it is an object of the present invention to provide a spin dryer incorporating an improved arrangement of this type.

The present invention provides a spin dryer having a rotatable drum, a motor operable to rotate the drum, a closure member having a closed position in which access to the drum is prevented and an open position in which access to the drum is permitted, and an interlock arrangement movable into an interlocking position by movement of the closure member into the closed position, in which interlocking position the arrangement prevents movement of the closure member into the open position; the interlock arrangement being responsive to air flow generated by rotation of the drum to be maintained in the interlocking position until the speed of rotation falls to a predetermined value.

The interlock arrangement, when in the interlocking position, may permit movement of the closure member from the closed position into an interlocked position in which access to the drum is also prevented. The motor may be arranged to be actuated by movement of the closure member into the closed position and the supply of power to the motor may be maintained by movement of the closure member from the closed position into the interlocked position.

In an embodiment of the invention, the interlock arrangement is engageable by an actuating element to be maintained thereby in the interlocking position when the closure member is in the closed position. The interlock arrangement is responsive to movement of the drum to be maintained thereby in the interlocking position when the closure member moves from the closed into the interlocked position.

Preferably, the interlock arrangement remains in, but is releasable from, the interlocking position when the speed of rotation of the drum falls below the said predetermined value.

The interlock arrangement may include a vane located in the path of air flow generated by rotation of the drum.

Advantageously, the dryer includes means arranged to prevent the interlock arrangement from being struck by the rotating drum.

The means may comprise a protective member which extends around the interlock arrangement between the interiock arrangement and the drum and, preferably,, is arranged to be struck by the rotating drum in the event of a predetermined imbalance condition in the drum. When so arranged, the protective member has the effect of retarding the drum and can be used to prevent the drum from attaining maximum spin speed while an imbalance condition exists.

By way of example, a spin dryer in accordance with the invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic view of the dryer showing the location of an interlock mechanism; Figure 2 shows the interlock mechanism in greater detail; Figures 3 to 8 show various stages in the operation of the interlock mechanism; Figure 9 is a fragmentary view, similar to Fig. 2 but showing a modification of the interlock mechanism, and Figure 10 is a section on the line X-X of Fig. 9.

The spin dryer shown diagrammatically in Fig. 1 is of conventional form and has a cylindrical body 1 housing the rotatable drum (not shown) driven by a motor (also not shown).

The upper end of the body is open to allow wet articles to be loaded into the drum to be spun dry. During the spinning operation, the body is closed by a lid 2 pivotally-mounted on the body. Diametrically-opposite the pivotal mounting, a main catch (not shown) is provided to hold the lid 2 in the closed position and, associated with the main catch, is an interlock mechanism 3 shown in greater detail in Fig. 2 and described below. Extending from the interlock mechanism is an actuator rod 4, the function of which will be described below, and the lid 2 carries a plunger 5 for actuating the interlock mechanism, as will also be described below.

The interlock mechanism 3 (Fig. 2), located on the rim 6 of the loading opening in the upper end of the spin dryer housing, comprises an open-ended cylindrical housing 7 in which is formed a longitudinally-extending slot 8. The actuator rod 4 extends from the lower end of the housing 7 and is reciprocally-movable into and out of the housing. At its lower end (not shown) the rod 4 is arranged to actuate the control switch of the motor and also a spring-loaded brake. The upper, open, end of the cylindrical housing 7 is arranged to receive the plunger 5 (Fig. 1) when the lid of the spin dryer is closed.

Adjacent the slot 8 in the housing 7, a hook-shaped safety catch 10 is pivotallymounted on the dryer body 1 so that it can pivot into and out of the housing 7 through the slot. The catch 10 is formed, adjacent the pivot 11, with an operating tab 12 and has an extension 13 which terminates in a vane 14 the purpose of which will be described below.

The operation of the interlock mechanism 3 will now be described with reference to Figs.

3 to 8. In these Figures, the actuator rod 4 has been omitted for clarity and so also has the lid 2 of the dryer, although the plunger 5 is shown.

Fig. 3 shows the interlock mechanism as the lid of the spin dryer is being closed but before it has been closed completely. The plunger 5, carried by the lid, enters the open end of the cylindrical housing 7, moves the actuator rod 4 (not shown) downwards and, via a cable connection, releases the springloaded brake on the motor. As can be seen from Fig. 3, the plunger 5 has a cut-away portion 15 facing the catch 10 and defining a hook-shaped portion 16 at the end of the plunger.

As the lid of the dryer moves into the closed position (Fig. 4), the bottom of the plunger 5 engages the tab 12 of the catch 10 and pivots the catch anticlockwise as seen in the drawings so that it passes through the slot 8 and enters the cut-away portion 15 of the plunger 5. This movement of the catch 10 pivots the vane 14 upwards from its generally vertical position of Fig. 3 through an angle of approximately 45 . At the same time, the continued downward movement of the actuator rod 4 has closed the control switch of the motor and the spin dryer comes into operation.

While in the closed position, the lid of the dryer is held by the manually-operable catch (not shown) conventionally provided for this purpose. As the drum of the dryer rotates, the air flow produced acts on the vane 14 of the interlock catch 10 in the direction indicated by the arrow 18 in Fig. 4 and reinforces the action of the plunger 5 on the tab 12; the catch 10 accordingly remains in the pivoted, or interlocking, position while the dryer is in operation.

When it is desired to terminate the spinning operation, the manually-operable catch of the lid is released allowing upward movement of the lid to commence (Fig. 5) under the resilient force of the brake cable and the brake return spring transmitted via the actuator rod 4 to the plunger 5. As the actuator rod 4 moves upwards, it opens the control switch to the motor and allows the brake to be applied so that the drum begins to slow down.

As the plunger 5 is pushed upwards, it moves out of engagement with the tab 12 but the air flow (arrows 18) acting on the vane 14 as a result of the rotation of the drum is still sufficient to maintain the catch 10 in the interlocking position, as shown. Consequently, the upward movement of the plunger 5 is halted as the hook-shaped portion 16 at the bottom of the plunger comes into engagement with the catch 10. This is the situation illustrated in Fig. 6 and corresponds to a slightly-open (or interlocked) position of the lid, insufficient to allow access to the rotating drum.

The vane 14 is so designed that it is maintained in the deflected position by a comparatively small air flow so that the Fig. 6 situation will be maintained until fhe drum of the dryer has come to a halt or at least until its speed of rotation has dropped below a predetermined safe value. If the lid of the dryer is now pushed down slightly to disengage the plunger hook 16 from the catch 10, the vane 14 is free to drop back to the substantially vertical position and return the catch 10 to the released position (Fig. 7). When the lid is released, it will now be free to move upwards under the action of the brake return spring and then to be opened manually to allow access to the drum (Fig. 8).

It will be appreciated that the interlock arrangement described, by responding to rotation of the drum, prevents the lid of the dryer from being opened only for as long as the drum continues to rotate at a speed above a predetermined value. The arrangement is, nevertheless, comparatively simple in construction. The interlock is positively actuated, not by the action of air flow on the vane 14, but by engagement of the plunger 5 with the catch 10 as the lid of the dryer is being closed.When the lid of the dryer is closed, the catch 10 of the interlock does not actually hold the plunger 5 although it is, of course, already in the interlocking position and ready to engage the plunger 5 when the lid is re leased and, during this stage of operation, it is again the plunger 5 that maintains the interlock in the actuated position, although now reinforced by the action of air flow on the vane 14. When, finally, the speed of rotation of the drum has dropped, the interlock is not released automatically but is maintained until released manually as illustrated in Fig. 7.

Various modifications could be made to the arrangement described above. For example, the dryer could have an outer lid with which the main latch is associated and an inner lid with which the interlock arrangement is associated and, in either case, the actuation of the motor and brake could be tied to operation of the main latch rather than to the interlock.

Alternatively, the interlock arrangement need not be separate from, but could be combined with, the main latch.

Advantageously, a protective bracket is provided to ensure that the rotating drum of the dryer cannot strike the air vane in the event of the drum being severely out of balance.

Such a bracket 20 is shown in Figs. 9 and 10 with an interlock mechanism 3 of the type shown in Fig. 2.

The bracket 20 is of elongated form, the ends 22 of the bracket being located against and secured to the inner surface of the cylindrical housing 1 of the dryer. The intermediate portion 24 of the bracket 20 is curved and extends inwardly of the housing 1 around the lower end of the vane 14 of the interlock mechanism. The intermediate portion 24 of the bracket thus provides, with the dryer housing, a protected space open at the top and bottom within which the free end of the vane 24 is located.

On its outer face (i.e. that facing the drum 26 of the dryer) the bracket 20 carries a strip 28 of rubber or other suitable protective material, providing a protective coating for this surface.

As can be seen from Fig. 9, most the vane 24 will still be exposed to the air flow produced as the drum of the dryer rotates and the interlock mechanism will, accordingly, function as already described with reference to Figs. 2 to 8. The drum 26 of the dryer (which is omitted from Fig. 9) is spaced from the inter-lock mechanism 3 as shown in Fig. 10 by a distance sufficient to ensure that, under normal running conditions, there is no possibility of the drum striking the air vane 24. In the event of severe imbalance in the drum, however, excessive movement of the drum can occur and, in the absence of the bracket 20, the drum could contact and damage the vane.

Such imbalance would normally be caused by an uneven distribution of articles within the drum and is usually noticed by the user who stops the machine and rearranges the load more evenly. Until that is done, the drum will strike the bracket 20 as it rotates and this not only prevents damage to the air vane but also retards the drum and prevents it from attaining maximum spin speed while the imbalance condition exists. The protective strip 28 serves to prevent the drum being damaged as it strikes the bracket 20 and also assists in retarding the drum.

Claims

1. A spin dryer having a rotatable drum, a motor operable to rotate the drum, a closure member having a closed position in which access to the drum is prevented and an open position in which access to the drum is permitted, and an interlock arrangement movable into an interlocking position by movement of the closure member into the closed position, in which interlocking position the arrangement prevents movement of the closure member into the open position; the interlock arrangement being responsive to air flow generated by rotation of the drum to be maintained in the interlocking position until the speed of rotation falls to a predetermined value.

2. A spin dryer as claimed in claim 1, in which the interlock arrangement, when in the interlocking position, permits movement of the closure member from the closed position into an interlocked position in which access to the drum is also prevented.

3. A spin dryer as claimed in claim 2, in which the supply of power to the motor is terminated by movement of the closure member from the closed position into the interlocked position.

4. A spin dryer as claimed in any one of the preceding claims in which the interlock arrangement is engageable by an actuating element to be maintained thereby in the interlocking position when the closure member is in the closed position.

5. A spin dryer as claimed in claim 4 when appendant to claim 2 or claim 3, in which the interlock arrangement is responsive to movement of the drum to be maintained thereby in the interlocking position when the closure member moves from the closed into the interlocked position.

6. A spin dryer as claimed in claim 4 or claim 5, in which the interlock arrangement is engageable by the actuating element to be moved thereby into the interlocking position when the closure member moves into the closed position.

7. A spin dryer as claimed in any one of claims 4 to 6, in which the actuating element is mounted on the closure member and is engageable by the interlock arrangement to hold the closure member in the interlocked position.

8. A spin dryer as claimed in any one of the preceding claims, in which the interlock arrangement remains in, but is releasable from, the interlocking position when the speed of rotation of the drum falls below the said predetermined value.

9. A spin dryer as claimed in claim 8 when appendant to claim 7, in which the interlock arrangement is maintained in the interlocking position by engagement with the actuating member when the speed of rotation of the drum falls below the said predetermined value.

10. A spin dryer as claimed in claim 8 or claim 9, in which the interlock arrangement is releasable by movement of the closure member towards the closed position.

11. A spin dryer as claimed in any one of the preceding claims, in which the interlock arrangement includes a vane located in the path of air flow generated by rotation of the drum.

12. A spin dryer as claimed in any one of the preceding claims, in which the motor is arranged to be actuated by movement of the closure member into the closed position.

13. A spin dryer as claimed in any one of the preceding claims, including a latch mechanism operable to maintain the closure member in the closed position.

14. A spin dryer as claimed in claim 13, in which the latch mechanism is manually operable.

15. A spin dryer as claimed in any one of the preceding claims, including means arranged to prevent the interlock arrangement from being struck by the rotating drum.

16. A spin dryer as claimed in claim 15, in which the means comprises a protective member which extends around the interlock arrangement between the interlock arrangement and the drum.

17. A spin dryer as claimed in claim 16, in which the protective member is arranged to be struck by the rotating drum in the event of a predetermined imbalance condition in the drum.

18. A spin dryer as claimed in claim 16 or claim 17, in which the protective member comprises a bracket which extends around the interlock arrangement and is provided with a protective coating on a surface facing the drum.

19. A spin dryer substantially as described herein with reference to, and as shown in, Figs. 1 to 8 or Figs. 1, 9 and 10 of the accompanying drawings.