GB2187831A - Centrifugal textile dryer - Google Patents

Abstract

While drum 2 rotates its lid 4 is free from contact with supporting arm 6, but they can be coupled for opening by rotation of handwheel 16, which raises threaded sleeve 14 to abut flange 19 on collar 17, and so lifts lid 4 and draws annular cone clutch components 20,21 together. The hollow centre of collar 17 provides a passage for nozzle 25, which is part of housing lid 3 and extends down the centre line of drum 2 during operation. <IMAGE>

Description

SPECIFICATION Centrifuges This invention relates to centrifuges comprising a housing cover end a drum cover which are each provided with a supporting arm which is mounted swingably on the housing and which has a tensioning device or coupling mechanism in order optionally to transfer the drum cover into a position in which it is freely rotationally movable with the drum relative to the supporting arm or else into a coupling position with the supporting arm.

Such a centrifuge, known from DE-PS 10 63 979 and serving more especially for the dewatering of textiles, is provided with a drum cover which is lockable in a reinforcing ring of the drum jacket against automatic release. For opening and closing, the drum cover is, in the same way as the housing cover, suspended from a supporting arm which is mounted swingably on the centrifuge housing. Arranged between the drum cover and the supporting arm is a coupling mechanism which is designated as a switching device and with which optionally the drum cover is transferrable into a position in which it is freely rotationally movable with the centrifuge drum relative to the supporting arm or else into a coupling position with the supporting arm for the opening of the drum cover unlocked from the centrifuge drum.

In the case of the known centrifuge, the coupling mechanism consists of a thrust part which is displaceable in the head of the supporting arm by an angle lever and which, in the position corresponding to the free rotary position of the drum cover, allows the supporting arm, under the action of a compensating spring, to lift off from the drum cover as far as an upward position limited by a lock bolt, whilst in the other switching position, corresponding to the coupling position of the drum cover with the supporting arm, perpendicularly displaceable thrust bolts are adjusted by the thrust part and apply themselves against the undersurface of a plate on a centric cover pivot freely penetrating the head of the supporting arm and the thrust part, and then press the supporting arm, with a cone coupling half provided on the undersurface of its head end, into a counter-coupling half which closes off the centric cover pivot at its foot.

The coupling mechanism of the known centrifuge is very complex and expensive, and requires more especially a large number of movable component parts, such as lifting pins, joint pins, thrust straps, axels and levers.

These movable parts are subject to wear and increase the maintenance expenditure of a centrifuge which is equipped with them. Moreover, such a centrifuge is noisy in operation on account of the high number of moving component parts.

Additionally a very substantial disadvantage of the known centrifuge is that the coupling mechanism prevents one from introducing through the cover centre a probe nozzle into the interior of the rotating centrifuge drum, as is, for example, necessary for the treatment of textile material with a reviving liquid.

The problem underlying the invention is to propose a centrifuge, having a coupling mechanism between the drum cover and the supporting arm thereof, which consists of only a few component parts which are simple to actuate, which causes no noise upon the rotation of the drum and whereby more especially the possibility is provided of inserting a probe nozzle, arranged securely for example in the centre of the housing cover which is likewise mounted swingably, in non-contact manner through the drum cover deep into the interior of the drum.

This problem is solved by the present invention in that it provides a centrifuge comprising a housing cover and a drum cover, which are each provided with a supporting arm which is hinged swingably to the housing, in which respect the supporting arm of the drum cover has a coupling mechanism with which optionally the drum cover is convertible into a position which is freely rotationally movable with the drum relative to the supporting arm or else into a coupling position with the supporting arm, characterised in that the coupling mechanism consists of a box fastened to the supporting arm of the drum cover and having an internal thread, and of a sleeve rotatable therein and having an external thread, in which respect the sleeve surrounds with play a raised cylindrical collar of the drum cover and fastened to the upper edge of the collar is a radially outwardly projecting flange, on the underside of which there acts the upper end face of the sleeve which can be rotated out of the box, whereby the drum cover can be braced with the supporting arm between the lower end face of the box and the upper end face of the sleeve.

As a result of the coupling mechanism formed substantially from a box fastened to the supporting arm of the drum cover and a sleeve which is rotatable therein, the centre of the drum cover remains free from parts of the coupling mechanism, so that the cylindrical collar, surrounded with play by the sleeve, of the drum cover forms a freely accessible shaft to the interior of the drum, which, with appropriately large cross-sectional dimensioning, makes it possible that a probe nozzle arranged securely in the centre of the housing cover can be swung, in non-contact manner through the cylindrical collar, into and out of the interior of the drum.

In accordance with a preferred proposal of the invention, the sleeve is rotatable in a simple manner by way of a handwheel which is fastened to the radially outwardly protruding flange.

Instead of actuating means which impair the free cross-section of the cylindrical collar of the drum cover, the handwheel can be so mounted with its spokes on the flange that the flange forms the hub of the handwheel and the comparatively short spokes end radially inwards outside the free collar cross-section.

In accordance with a further preferred proposal of the invention, fastened on the drum cover is a cone ring which surrounds the cylindrical collar and with which there is associated a cone counter-ring which is fastened on the lower end face of the box.

As a result of the cone ring on the drum cover and the cone counter-ring on the box, the drum cover can be coupled in a forcelocking and form-locking connection with the supporting arm, it can be swung with this into the open position and again into a specific closure position and be uncoupled from the supporting arm.

In order to be able to indicate the proper coupling or respectively uncoupling between the drum cover and the supporting arm, in accordance with a further preferred proposal of the invention a pin is mounted in the cone counter-ring and is axially displaceably by the cone ring and which as a function of its position indicates the coupling and uncoupling position of the drum cover.

Preferably, in the uncoupled position of the drum cover, through the action of a leaf spring the pin protruder in the direction of the cone ring, for which purpose one end of the restrained leaf spring acts on that end of the pin which points away from the cone ring. In the coupled position of the drum cover, the cone ring presses against that end of the pin which faces it and compels this to extend, against the action of the leaf spring, into the cone counter-ring.

In accordance with a further preferred proposal of the invention, the deflection of the leaf spring can be utilised to actuate a switch which in turn actuates the opening of the drum cover. The actuation of the switch can serve, for example, for opening a valve, in order that a pressure medium can act on a cylinder/piston-rod unit which acts on the sup porting arm of the drum and housing cover, whereby the swivel movement of the covers out of the closed position into the open position is triggered.

The invention will be described further, by way of example, with reference to the accom panying drawings in which: Fig. 1 is a part-sectional elevation of a preferred embodiment of the centrifuge of the invention; Fig. 2 is a plan view of part of the centrifuge of Fig. 1; Figs. 3 and 4 are vertical cross-sections through a coupling mechanism of the centrifuge of Figs. 1 and 2 in the coupling and the uncoupling state respectively; and Fig. 5 is an enlarged cross-sectional view of part of the coupling mechanism of Figs. 3 and 4.

The centrifuge consists in a conventional manner of a cylindrical housing 1, in which there is mounted concentrically a drum 2 which can be rotated about its axis. The housing 1 and the drum 2 are sealable frontally by covers 3 and 4 respectively, which covers 3 and 4 are transferrable by supporting arms 5 and 6 respectively from a vertical open position into a horizontal closed position.

For this purpose, the supporting arms 5 and 6 are swingable about an axel 7 which is held in a bearing 8 fastened to the housing 1. The swivel motion of the supporting arms 5 and 6, and thus of the covers 3 and 4, is effected by means of a cylinder/piston-rod unit 9, which acts with one end hingedly on the supporting arms 5 and 6 and with its other end hingedly on the housing 1.

The drum cover 4 is lockable in the conventional manner with its outer edge on a reinforcing ring 10 on the upper edge of the drum 2.

Provided between the drum cover 4 and its supporting arm 6 is a coupling mechanism 11, the structure and mode of operation of which emerges particularly clearly from Figs. 3 to 5.

The coupling mechanism consists substantially of a box 13 with an internal thread, which is preferably a multiple trapezoidal thread. The box 13, which is connected securely to the free end of the supporting arm 6, has a sleeve 14 provided with an external thread, corresponding to the internal thread of the box 13, by which it is screwed into the box 13. The upper edge the sleeve 14 is provided with a radially outwardly protruding flange, on which act spokes 15 of a handwheel 16.

The drum cover 4 is provided with a raised cylindrical collar 17, which is so conducted concentrically through the sleeve 14 that a free annular space 18 remains between the outer circumference of the collar 17 and the inner circumference of the sleeve 14. Fastened to the upper edge of the collar 17 is a flange 19 which likewise protrudes radially outwards and which engages over the end face of the sleeve 14.

Arranged securely around the collar 17 on the drum cover 4 is a cone ring 20. Arranged likewise securely on the underside of the box 13, and lying opposite to the cone ring 20, is a cone counter-ring 21.

The mode of operation of the coupling mechanism is as follows: As a result of an appropriate rotary motion of the handwheel 16, the sleeve 14 can be moved out of the box 13 to such an extent that as shown in Fig. 3 the end face of the sleeve 14 has, by way of the flange 10 and the collar 17, so raised the drum cover 4 that the cone ring 20 is drawn into the cone counter-ring 21 and tightened securely thereagainst. In this state, the drum cover 4 is connected in force-locking and form-locking manner to the supporting arm 6.

As a result of an appropriate counter-rotation of the handwheel 16, the sleeve 14 can be moved into the box 13 to such an extent that as shown in Fig. 4 the end face of the sleeve 14 is spaced from the flange 19. Resting of the drum cover 4 onto the drum 2 prevents any further lowering. In this cover position, the cone ring 20 has also separated from the cone counter-ring 21, so that any contact between the coupling mechanism and the drum cover is prevented.

As shown by Fig. 5, the coupling and uncoupling position of the drum cover 4 can be indicated by a pin 21 which is mounted in the cone counter-ring 21 and which protrudes, under the force of a leaf spring 23, in the direction of the cone ring 20, insofar as in the uncoupling position it is not forced back by the cone ring 20. Only when the cone ring 20 butts against the cone counter-ring 21, i.e. in the coupling position, is the pin 22 forcedback against the action of the leaf spring 23 and deflects the leaf spring 23 in a reinforced manner. In this respect, the leaf spring 23 actuates a switch 24 whereby, for example, a valve in a pressure-medium line can be opened, in order to act upon the piston-rod unit 9 for the cover actuation.

A nozzle connection 25 arranged on the underside of the housing cover 3 in the centre thereof is swingable, by way of the free cross-section defined by the collar 17, in an unimpeded manner deep into the interior of the drum 2 and is swingable with the housing cover 3, in an equally unimpeded manner, out of the interior of the drum 2, without, in addition to the cover actuation, other centrifuge parts having to be dismantled and re-assembled.

Claims (7)

1. A centrifuge comprising a housing cover and a drum cover, which are each provided with a supporting arm which is hinged swingably to the housing, in which respect the supporting arm of the drum cover has a coupling mechanism with which optionally the drum cover is convertible into a position which is freely rotationally movable with the drum relative to the supporting arm or else into a coupling position with the supporting arm, characterised in that the coupling mechanism consists of a box fastened to the supporting arm of the drum cover and having an internal thread, and of a sleeve rotatable therein and having an external thread, in which respect the sleeve surrounds with play a raised cylindrical collar of the drum cover and fastened to the upper edge of the collar is a radially outwardly projecting flange, on the underside of which there acts the upper end face of the sleeve which can be rotated out of the box, whereby the drum cover can be braced with the supporting arm between the lower end face of the box and the upper end face of the sleeve.

2. A centrifuge as claimed in claim 1, characterised in that the sleeve is rotatable by way of a handwheel which is fastened to a radially outwardly projecting flange.

3. A centrifuge as claimed in claims 1 and 2, characterised in that fastened on the drum cover is a cone ring which surrounds the cylindrical collar and with which there is associated a cone counter-ring which is fastened on the lower end face of the box.

4. A centrifuge as claimed in claims 1 to 3, characterised in that arranged in the cone counter-ring is a pin which is mounted so as to be axially displaceable by the cone ring and which, as a function of its position, indicates the coupling or uncoupling position of the drum cover.

5. A centrifuge as claimed in claims 1 to 4, characterised in that the pin in the uncoupled position of the drum cover protrudes, through the action of a leaf spring, in the direction of the cone ring and in the coupled position of the drum cover is forced-back, against the effect of the leaf spring, in the cone counterring.

6. A centrifuge as claimed in claims 1 to 5, characterised in that there is provided a switch which as a result of the deflection of the leaf spring actuates the opening of the drum cover.

7. A centrifuge substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.