US3691645A

US3691645A - Spin driers

Info

Publication number: US3691645A
Application number: US125708A
Authority: US
Inventors: Barry Herbert Nethersell
Original assignee: British Domestic Appliances Ltd
Current assignee: British Domestic Appliances Ltd
Priority date: 1970-03-20
Filing date: 1971-03-18
Publication date: 1972-09-19
Anticipated expiration: 1989-09-19
Also published as: GB1298988A; CA978863A; NO131233C; ZA711756B; NO131233B

Abstract

A spin drier having a mechanical interlock for locking the lid in a closed condition and enabling drive means to rotate the drum. When the interlock is released, the drum is brought to a halt, while the lid is unlocked after a delay sufficient for the drum to come to rest, the delay being determined by hydraulic or pneumatic damping means mechanically coupled to the interlock. The interlock is released by releasing a latch, allowing the lid to open by a small amount, not sufficient to permit access to the drum.

Description

United States Patent Nethersell 51 Sept. 19, 1972 [54] SPIN DRIERS [72] Barry Herbert Nethersell, Deganwy,

Wales Assignee: British Domestic Appliances Limited, Peterborough, England Filed: March 18, 1971 Appl. No.: 125,708

Inventor:

[30] Foreign Application Priority Data March 20, 1970 Great Britain ......l3,486/70 US. Cl. ..34/58, 192/136, 210/146 Int. Cl ..F26b 17/24 Field of Search ..34/43, 58, 8; 192/136;

References Cited UNITED STATES PATENTS 3/1925 Co lclough 192/ 136 Daubman ..192/ 136 X Hopkins ..210/1 46 Primary Examiner--Carrol1 B. Dority, Jr. Attorney-Larson, Taylor & Hinds 5 7 ABSTRACT A spin drier having a mechanical interlock for locking the lid in a closed condition and enabling drive means to rotate the drum. When the interlock is released, the drum is brought to a halt, while the lid isunlocked after a delay sufficient for the drum to come to rest, the delay being determined by hydraulic or pneumatic damping means mechanically coupled to the interlock. The interlock is released by releasing a latch, allowing the lid to open by a small amount, not sufficient to permit access to the drum.

10 Claims, 3 Drawing Figures SPIN mums This invention relates to spin driers for centrifugally drying clothes or the like.

Such a spin drier comprises a rotatable drum, housed within a cabinet and adapted to receive the clothes or other articles to be dried, the cabinet being provided with a lid or door, hereinafter referred to simply as a lid for convenience, the lid when closed serving to protect an operator from accidental contact with the drum when the latter is in motion. In such a spin drier it is often desirable to provide some form of safety interlock arrangement in order to prevent the lid from being opened when the drum is rotating at a speed for which access to the drum would be dangerous. It is an object of the invention to provide a spin drier having a novel form of safety interlock arrangement.

According to a first aspect of the invention, in a spin drier comprising a rotatable drum housed within a cabinet having alid which when closed, or opened byat most a limited amount, prevents access to the drum, there is provided means for driving the drum only when thelid is closed, locking means biased into an inoperative condition in which it permits the lid to be opened, and movable into an operative condition in which it prevents the lid from being opened by more than said limited amount, operating means having a first condition in which it mechanically urges the locking means into the operative condition and also enables the driving means to effect the rotation of the drum, said operating means also having a second condition in whichit releases the locking means and inhibits rotatioriof the drum, and fluid damping means mechanically coupled to the locking means for delaying the return of the latter to its inoperative condition, following its release by the operating means, for a time sufficient to allow the speed of the drum to drop below a predetermined value for which access to the drum is safe.

Accordingto a second aspect of the invention, in a spin drier comprising arotatable drumhoused within a cabinet having a lid which when closed, or opened by at most a limited amount, prevents access to the drum, there is provided means for driving the drum,locking means biased into an inoperative condition in which it permits the lid to be opened, and movable into an operative condition in which it prevents the lid from being opened by more than said limited amount, operating means having a first condition into which it is mechanically urged by the lid when fully closed and in which condition the operating means mechanically urgesthe locking means into the operative condition and also enables the driving means to effect the rotation of the drum, said operating means also having a second conditioninto which it is urged when the lid is opened by said limited amount, and in which second condition the operating means releases the locking means and inhibits rotation of the drum, and fluid damping means mechanically coupled to theilocking means for delaying the return of thelatter toits inoperative condition, following its release by the operating means, for a time sufficient to allow the speed of the drum to drop below a predetermined value for which access to the drum is safe.

The fluid damping means may be either hydraulic or pneumatic, and conveniently comprises a pistonandcylinder unit incorporating a restricted opening through which a fluid, for example air or oil, is forced by movement of the piston on return of the locking means to its inoperative condition, under the action of the bias, the opening limiting the passage of the fluid and hence delaying the return of the locking means. The restricted opening is conveniently adjustable in order to vary the length of said delay.

The locking means can be biased into its inoperative condition either by a spring or by gravity. Conveniently, there is provided latching means for holding the lid fully closed. In one particular arrangement in accordance with the invention there is provided resilient means urging the lid out of its fully closed position. Thus, in this arrangement, on release of the latching means, the lid will be opened by said limited amount, whereupon the drum will cease to be driven.

Conveniently, the operating means when in its said second condition, inhibits rotation of the drum by operation of a switch controlling the supply of electric current to the driving means, and preferably, the operating means, when in its second condition, also acts to apply a brake to the drum.

One spin drier in accordance with the invention will now be described, byway of example, with reference to the accompanying drawings, of which:

FIG. 1 is a part-sectional elevation of the spin drier in accordance with the invention;

FIG. 2 is a sectional view of a part of the spin drier, on an enlarged scale compared with FIG. 1; and

FIG. 3 is a part-sectional view in the direction of arrowA in FIG. 2.

Referring to FIGS. 1 and 2, the spin drier has a clothes drum 1 having an access opening 2 at its upper end and perforations 3a in its cylindrical wall 3 for the egress of liquid expelled from clothes contained in the drum. The drum is fixed by means of bolts 4 passing through the lower wall 5 of the drum to a spider 6 which serves both to stiffen and to support the drum. The spider 6 is securedto the output shaft 7 of an electric drive motor 8 which is supported from a sloping floor 9 of the spin dryer cabinet 11 by a plurality of resilient members 12. The cabinet 11 is supported on rubber feet 13. Liquid centrifuged from clothes contained in the drum :passes through the perforations 3a on to the sloping floor 9 from where it drains via a spout (not shown) into a suitable receptacle.

The cabinet 11 is surmounted at its upper end by a circular flanged end cap 15 which is secured to the cabinet by screws (not shown) and which is providedat its center with an access opening 16 closeable by a circular lid 17 pivoted at one side to the end cap 15 by means of a hinge 18 which is riveted to the lid and bolted to the end cap. A moulded. plastics handle 19 is secured to the lid 17 opposite the hinge18 by means of screws 20 (see FIG. 2), and mounted within the handle andsecured to it is an operating member 21 within which alatch 22 ispivotally mounted about a pin 23 so as to be capable of operation by depression of a release knob 24 against a return spring 25. Both member 21, which carries a foot 21a and latch 22 are arranged. to enter an aperture 26 in the end cap 15, whereupon a tongue portion 22a of the latch engages with a projection 27 onthe end cap so as to hold the'lid firmly closed.

As the lid is closed the lower end of the operating member 21 engages with a platform 28a which surmounts and is secured to the turned-over end of a rigid interlock rod 28 which on downward movement of the lid 17 and, by means of a bowden cable 29, one end of which is attached to the lower end of the lever, releases a brake mechanism 30 associated with the motor 8, and, by means of an actuator 31, operates a microswitch 32 to complete the electrical supply to the motor thereby causing the drum 1 to rotate. A coil spring 33 acting between the rod 28 and the floor 9 of the cabinet 11 is arranged to return the rod to its upper position as soon as it is free to do so, thereby to allow operation of the microswitch 32 to interrupt the electrical supply to the motor and to actuate the brake mechanism 30, thus bringing the drum 1 to rest. A flexible sealing sleeve-34 mounted between the rod 28 and the floor of the cabinet ensures that no liquid can come into contact with the coil spring or pass through the floor of the cabinet and adversely affect the electrical system.

Referring now to FIGS. 2 and 3, there is provided, within the aperture 26, locking means comprising a lock bolt 41, one end of which is attached to a rod 42, forming part of a pistonand-cylinder unit 43 mounted on a bracket 44, and the other end of which is arranged to slide within an aperture 45a in an upturned part 45 of the bracket 44.

The pistonand-cylinder unit 43 comprises a cylinder 46 within which is mounted a piston 47 comprising a circular metal disc 48, to which the rod 42 is fastened, and a circular flexible sealing disc 49, which ensures that the piston is a sliding air-tight fit within the cylinder. Control of the flow of air out of the cylinder 46 through a bleed hold 50, and hence control of the rate of movement of the piston 47 into the cylinder 46, is effected by means of an adjusting screw 51. A coil spring 52 is provided within the cylinder 46 and is arranged to urge the piston .47 in such a direction as to draw the rod 42 into the cylinder.

When the rod 42 is fully drawn into the cylinder 46, an intermediate portion 53 of the lock bolt 41, of reduced cross section compared with the rest of the bolt, lies adjacent to the foot 21a of the operating member 21, and allows the foot to pass into and out of the aperture 26 unimpeded by the bolt 41. Thus the lid 17 can be fully opened, and the locking means is therefore in an inoperative condition. However, when the lock bolt 41 is' slid along into the aperture 45a the bolt will retain the foot 21a.in the aperture 26 and thereby prevent the lid from opening by more than a limited amount, as shown in FIG. 2.

Movement of the bolt 41 from its inoperative to its operative position is effected by means of an actuating lever 54, which is pivoted about a pin 55 secured to the bracket 44, which in turn pivots a toggle 56 about a pin 57 attached to the bracket 44, the toggle carrying a stirrup 58 which engages in a grooved portion 59 of the piston rod 42, so as to effect longitudinal movement of the piston and the bolt. The actuating lever 54 is operated, when the lid 17 is closed, by downward movement of the member 21 and the turned-over end of the rod 28.

Thus, the rod 28, the lever 54, and the toggle 56 constitute an operating means, which is urged into a first condition when the lid 17 is fully closed, in which condition the operating means urges the bolt 41 into its operative condition and enables the electric drive motor 8. When the lid 17 is opened by a limited amount, as shown in FIG. 2, the operating means adopts a second condition, in which it releases the bolt 41, and inhibits rotation of the drum, by disconnecting the supply to the motor 8 and by applying the brake 30.

In operation, clothes to be dried are loaded into the drum 1 through the access opening 16, and the lid is then closed, and held fully closed by the latch 22. The operation of closing the lid moves the interlock rod 28 downwards and thereby releases the brake 30 and completes the electrical circuit to the motor 8. As the rod 28 is moved downwards by the member 21, the lock bolt 41 is slid across the foot 21a into its operative position, the piston 47 also moving within the cylinder 46, whereupon air flows into the cylinder behind the piston past the sealing disc 49. The lock bolt 41 is held in this operative position, against the bias of the spring 52, for as long as the lid 17 is held fully closed by the latch 22.

When it is desired to terminate the drying operation the knob 24 is depressed, so as to release the latch 22, whereupon the upward force exerted by the spring 33 on the rod 28 operates to open the lid 17 by a small amount, and to move the rod upwards and break the electrical supply to the motor 8 by actuation of the micro-switch 32 and at the same time to operate the braking mechanism 30.

The foot 210, however, is held by the lock bolt 41 so that the lid 17 is prevented from opening by more than a limited amount, as shown in FIG. 2. The lock bolt gradually returns to its inoperative position, under the bias of the spring 52, after a predetermined delay, determined by the time taken for air to be expelled from the cylinder 46 through the bleed hole 50 by the piston 47. This delay can be adjusted by adjustment of the screw 51, so as to ensure that the clothes drum 1 is brought substantially to rest or at least to a speed for which access to the drum is safe (for example, about 50 rpm.) by the brake 30 before the lock bolt returns to its inoperative condition. The delay time is typically arranged to be in the order of 10 seconds.

When the bolt 41 has returned to its inoperative condition, the lid 17 can be fully opened, to provide access to the drum 1 for removal of the clothes.

Should the electrical supply fail during a spinning operation the lid cannot be opened until the latch 22 has been released, and then only after the time delay. Therefore, in this case also, an operator cannot gain access to the clothes drum 1 until it is safe to do so. Thus the interlock arrangement operates correctly even in the case of electrical supply failure. On the other hand, opening of the lid is not completely prevented by failure of the electrical supply, as it is in some purely electrical interlock arrangements.

It will be appreciated that the pneumatic pistonandcylinder unit 43 could be replaced by some form of hydraulic device.

It will also be appreciated that the invention is not restricted to spin driers as such, but could equally be applied to a combined washing and drying machine having a clothes drum in which both washing and spin drying operations are carried out.

I claim:

1. A spin drier comprising a rotatable drum housed within a cabinet having a lid which when closed, or opened by at most a limited amount, prevents access to the drum, wherein there is provided means for driving the drum, only when the lid is closed, locking means biased into an inoperative condition in which it permits the lid to be opened, and movable into an operative condition in which it prevents the lid from being opened by more than said limited amount, operating means having a first condition in which it mechanically urges the locking means into the operative condition and also enables the driving means to effect the rotation of the drum, said operating means also having a second condition in which it releases the locking means and inhibits rotation of the drum, and fluid damping means mechanically coupled to the locking means for delaying the return of the latter to its inoperative condi tion, following its release by the operating means, for a time sufficient to allow the speed of the drum to drop below a predetermined value for which access to the drum is safe.

2. A spin drier according to claim 1 wherein said damping means comprises a pistonand-cylinder unit incorporating a restricted opening through which a fluid is forced by movement of the piston on return of the locking means to its inoperative condition under the action of the bias, the opening limiting the passage of the fluid and hence delaying the return of the locking means.

3. A spin drier according to claim 1 wherein there is provided latching means for holding the lid fully closed.

4. A spin drier according to claim 3 wherein there is provided resilient means urging the lid out of its fully closed position.

5. A spin drier according to claim 1 wherein the operating means when in its second position inhibits rotation of the drum by operation of a switch controlling supply of electric current to the driving means and by applying a brake to the drum.

6. A spin drier comprising a rotatable drum housed within a cabinet having a lid which when closed, or

opened by at most a limited amount, prevents access to the drum, wherein there is provided means for driving the drum, locking means biased into an inoperative condition in which it permits the lid to be opened, and movable into an operative condition in which it prevents the lid from being opened by more than said limited amount, operating means having a first condition into which it is mechanically urged by the lid when fully closed and in which condition the operating means mechanically urges the locking means into the operative condition and also enables the driving means to effect the rotation of the drum, said operating means also having a second condition into which it is urged when the lid is opened by said limited amount, and in which second condition the operating means releases the locking means and inhibits rotation of the drum, and fluid damping means mechanically coupled to the locking means for delaying the return of the latter to its inoperative condition, following its release by the operating means, for a time sufficient to allow the speed of the drum to drop below a predetermined value for which access to the drum is safe.

7. A spin drier according to claim 6 wherein said damping means comprises a pistonand-cylinder unit incorporatin a restricted opening through which a fluid is force by movement of the piston on return of the locking means to its inoperative condition under the action of the bias, the opening limiting the passage of the fluid and hence delaying the return of the locking means.

8. A spin drier according to claim 6 wherein there is provided latching means for holding the lid fully closed.

9. A spin drier according to claim 8 wherein there is provided resilient means urging the lid out of its fully closed position.

-10. A spin drier according to claim 6 wherein the operating means when in its said position inhibits rotation of the drum by operation of a switch controlling supply of electric current to the driving means, and by applying a brake to the drum.

Claims

1. A spin drier comprising a rotatable drum housed within a cabinet having a lid which when closed, or opened by at most a limited amount, prevents access to the drum, wherein there is provided means for driving the drum, only when the lid is closed, locking means biased into an inoperative condition in which it permits the lid to be opened, and movable into an operative condition in which it prevents the lid from being opened by more than said limited amount, operating means having a first condition in which it mechanically urges the locking means into the operative condition and also enables the driving means to effect the rotation of the drum, said operating means also having a second condition in which it releases the locking means and inhibits rotation of the drum, and fluid damping means mechanically coupled to the locking means for delaying the return of the latter to its inoperative condition, following its release by the operating means, for a time sufficient to allow the speed of the drum to drop below a predetermined value for which access to the drum is safe.

2. A spin drier according to claim 1 wherein said damping means comprises a piston- and-cylinder unit incorporating a restricted opening through which a fluid is forced by movement of the piston on return of the locking means to its inoperative condition under the action of the bias, the opening limiting the passage of the fluid and hence delaying the return of the locking means.

6. A spin drier comprising a rotatable drum housed within a cabinet having a lid which when closed, or opened by at most a limited amount, prevents access to the drum, wherein there is provided means for driving the drum, locking means biased into an inoperative condition in which it permits the lid to be opened, and movable into an operative condition in which it prevents the lid from being opened by more than said limited amount, operating means having a first condition into which it is mechanically urged by the lid when fully closed and in which condition the operating means mechanically urges the locking means into the operative condition and also enables the driving means to effect the rotation of the drum, said operating means also having a second condition into which it is urged when the lid is opened by said limited amount, and in which second condition the operating means releases the locking means and inhibits rotation of the drum, and fluid damping means mechanically coupled to the locking means for delaying the return of the latter to its inoperative condition, following its release by the operating means, for a time sufficient to allow the speed of the drum to drop below a predetermined value for which access to the drum is safe.

7. A spin drier according to claim 6 wherein said damping means comprises a piston- and-cylinder unit incorporating a restricted opening through which a fluid is forced by movement of the piston on return of the locking means to its inoperative condition under the action of the bias, the opening limiting the passage of the fluid and hence delaying the return of the locking means.

10. A spin drier according to claim 6 wherein the operating means when in its said position inhibits rotation of the drum by operation of a switch controlling supply of electric current to the driving means, and by applying a brake to the drum.