GB2168536A - Programme controller - Google Patents

Abstract

A programme controller for washing machines comprises a manually rotatable preselection dial 6, and an axially adjustable control disc 7,8 which is coupled to a programme drum 4 so as to be non-rotatable in relation thereto. Upon manual movement of the preselection dial 6, the control disc 7,8 is axially moved by camming devices 25,28 against spring bias 9 to actuate a control switch 15 causing the drive of the programme drum 4 to be switched to high speed until the programme drum 4 has followed an adjustment of the preselection dial effected by hand. An axially and radially movable sensing finger 17 normally runs on a cam track 21 provided at the circumference of the preselection dial 6 but on axial displacement of the control disc 7, 8, the sensing finger 17 drops into a gap formed between the preselection dial 6 and a ring 7 of the control disc and holds the ring 7 in the axially adjusted position until the sensing finger 17 can move through an associated control notch 22 provided in the cam track 21 and associated with a programme starting point. <IMAGE>

Description

SPECIFICATION Programme controller with a follow-up control This invention relates to a manually presettable programme controller of the kind having a rotary programme drum arranged to be driven by means of a motor, a rotatable programme preselection dial arranged for manual rotation relatively to said programme drum for presetting a predetermined programme starting position of the programme drum, and a servo mechanism responsive to rotation of said preselection dial towards a preselected programme setting position, for bringing said programme drum and, if necessary, the programme selection dial to a correspondingly selected starting point.

In a known programme controller of this type (DEOS 25 12 900), a control disc, which axially displaceable against the force of a spring and which is coupled to an axially nondisplaceable preselection dial through a withdrawal device is connected to a driven programme drum in such a manner as to be held against rotation but axially displaceable. In the engaged state, the withdrawal device permits a rigid rotational connection in the direction of rotation preset by the programme drum and in the other direction of rotation causes an axial displacement of the control disc over a small predetermined angleofrotation. On a further angle of rotation, after the axial displacement, free rotation between control disc and preselection dial is possible.When the control disc is displaced axially, an increased speed of rotation of the drive motor for the programme drum is switched on through a control switch and the programme drums stepped on at high speed. At the outer circumference of the control disc there is a control path with control notches with which there is associated a sensing finger of a control switch for the high speed. Associated with the control notches are specific programme points of the programme drum, for example the beginning of a preliminary rinsing programme, the beginning of a main wash programme, the beginning or the beginnings of one or more rinsing programmes and of a spin-drying programme. In this case, the sensing finger is disposed on a control lever which is only adjustable radially and runs on the outer circumference of the control path when the control disc is not axially.On the other hand, when the control disc is displaced axially, the sensing finger drops radially in front of the end face of the control path and when the withdrawal device returns to its position of rest, the sensing finger is lifted radially outwards by the control notches which then come into engagement with it. In this case, the high speed for the programme drum is switched off. With a construction of a programme controller of this type, differently stepped, relatively flat control notches are necessary which can lead to incorrect control operations in the event of even a slight wear of the edges. At the same time, when switching over from high speed to normal speed, it is necessary to pass through the neutral position of the control switch associated with the two control devices as a result of which a permanent stoppage may occur after the follow-up of the programme drum.

It is an object of the present invention to provide a programme controller of the kind initially referred to which is of simplified construction and has improved reliability.

The invention accordingly provides a manually presettable programme controller, comprising a rotary programme drum arranged to be driven by means of a motor, a rotatable programme preselection dial arranged for manual rotation relatively to said programme drum for presetting a predetermined programme starting position of the programme drum, and a servo-mechanism responsive to rotation of said preselection dial towards a preselected programme setting position, for bringing said programme drum and, if necessary, the programme selection dial to a correspondingly selected starting point, said servo-mechanism comprising a control switch for actuating said motor to rotate said programme drum, a switch actuating means axially movable relatively to said programme drum but fixed with respect thereto in the direction of rotation and axially biased relatively to said preselection dial said switch actuating means being so arranged to co-operate with said programme selection dial that upon rotary movement of the latter relatively to the programme drum in a direction towards said predetermined starting position said switch actuating means is shifted axially against said bias to actuate said control switch, and an indexing member for retaining said switch actuating means against said bias in the switch actuating position until the programme preselection dial is located in said predetermined starting position, said indexing member comprising a lever having a cam follower which is movable both axially and radially relatively to a cam track associated with said programme selection dial and having radial indexing notches which are open axially towards said switch actuating means, the arrangement being such that upon axial shifting of said switch actuating means against said bias, said cam follower can move axially to fall into a correspondingly formed gap, and thus latch the switch actuating means in the displaced position until the cam follower becomes axialled aligned with and can move axially into a said indexing notch of the cam track.

In a construction of a programme controller according to the invention, the axial shifting of the switch actuating means is used alone for the actuation of the control switch to control the motor independently of the angular positions of rotation of the actuating means. At the same time, after an axial displacement of the actuating means out of its position of rest, a camfollower of a locking lever, which drops into the gap formed, prevents the complete restoring of the actuating means when the programme drum and the preselection dial regain the relative angular positions corresponding to the position of rest but the next programme starting point, following on the manual rotational adjustment, with the associated control notch, is not yet situated within the range of action of the cam follower.Only when the cam follower can be engaged axially in the associated control notch can the switch actuating means return to its axial position of rest and the control switch be opened. As a result, the actuating means, the actuation lever for the control switch, the cam follower and the curved cam track associated with the preselection dial can be constructed in a simple manner, while, in particular, the cam track and the cam follower only have to execute one control operation in each position. These components can therefore also be simple in design and do not require any expensive tools for their production.

In order to improve the operation of the switch actuating means it may be composed of two rings, the first ring being held on the programme drum for axial displacement and being prestressed towards the preselection dial by a compression spring while the second ring is held for axial displacement in relation to the first and is likewise prestressed towards the preselection dial by a further compression spring. At the same time, the second ring carries cam projections which co-operate with corresponding cam recesses in the preselection dial. The second ring bears with its side opposite to the cam projections against the first ring when the two rings are in the axially nondisplaced position and in the axially completely displaced position.As a result of this, the cam projections can engage completely in the associated cam recesses without the ring co-operating with the control switch having to return it to its position of rest. As a result of the complete engagement of cam projections in the cam recesses, a reliable driving connection is ensured between the programme drum and the preselection dial.

Otherwise, with an undivided actuating means, the cam projections can only engage in the associated cam recesses by the difference amount by which the actuating means can slide back axially until it bears against the cam follower which is supported on the adjacent end face of the cam track, when the cam projections and recesses again come into engagement. The axial interengagement of the cam projections and recesses must therefore be greater than the width of the cam follower of the locking lever.

Further preferred features and advantages of the invention will become apparent from the following description and the appended claims.

The invention is illustrated by way of example in the accompanying drawings in which: Figure 1 is a longitudinal section through a programme controller according to the invention, Figure 2 is a partial longitudinal section of the programme controller of Figure 1, shown with components of a servo control mechanism in a position of rest, Figure 3 is a partial longitudinal section corresponding to Figure 2, shown with the components displaced following an initial manual setting of the programme selection dial.

Figure 4 is a further partial longitudinal section corresponding to Figure 2, shown with the components in a position shortly before completion of a setting operation by the servo control motor.

Figure 5 is a sectional view through the programme controller as shown in Figure 2 on the line A-A of Figure 2.

Figure 6 is a partial sectional view on the line B-B of Figure 5.

Figure 7 is a view similar to that of Figure 6, but showing the components in relatively displaced positions, Figure 8 is a section through the programme controller on the line C-C in Figure 2, in the region of the control switch, and Figure 9 shows a fragmentary view corresponding to a part of Figure 8, but showing the components in relatively displaced positions.

In the programme controller illustrated in the drawings, a drive motor 2, which drives a reversing drum 3 and a programme drum 4 through a gear, not illustrated in detail, is flange-mounted on a supporting frame 1. Associated with the drums 3, 4 is a common shaft 5 which is rotatable independently of the drums 3, 4. Mounted on the shaft 5 so as to be held against rotation in relation thereto and axially non-displaceaable is a preselection dial 6 which co-operates with a control disc which is formed from two rings 7 and 8 and is adapted for axial displacement but held against rotation in relation to the programme drum 4. In the upper portion of Figure 1, the control disc 7, 8 is illustrated in its position of rest and in the lower portion it is illustrated in its axially adjusted position. The first ring 7 is subject to the action of the force of a compression spring 9 which urges the ring 7 towards the preselection dial 6. A further compression spring 10 is mounted on the first ring 7 and likewise urges the second ring 8 towards the preselection dial 6. In the axial direction, the second ring 8 is situated between the first ring 7 and the preselection dial 6. The rings 7, 8 of the control disc are both held against rotation but so as to be axially displaceable by extensions 11 projecting axially from the program drum 4. The extension 11 engages through the first ring 7 while the second ring 8 engages with entrainment webs 12 through the ring 7 likewise in the U-shaped extension 11.At the end face adjacent to the program drum 4, the first ring 7 comprises an approach slope 13 which cooperates with a control lever 14 of a control switch 15, which control lever is adjustable radially in relation to the shaft 5. When the control disc 7, 8 is adjusted axially, the control switch 15 switches on a high speed operation whereby the program drum is driven at an increased speed in comparison with its stepping on speed according to the program, so as to be able to travel over unnecessary portions of program in a short time. The compression spring 9 is otherwise supported on a supporting disc 16 associated with the program drum 4. A sensing finger 17, which is adapted for radial and axial adjustment, serves to control the axial displacement of the control disc 7, 8.At the circumference, in the region remote from the program drum 4, the preselection dial 6 comprises detent notches 18 which cooperate with a pawl 20 subject to the force of a compression spring 19 (Figure 5). The detent notches 18 are associated with starting points of the working program laid down on the program drum, for example the beginning of a preliminary washing operation, of a main washing operation, rinsing operations and spin-drying operations. Provided beside the detent notches 18 at the circumference of the preselection dial 6 at the side adjacent to the ring 7 is a control path 21 which comprises control notches 22. These control notches are open towards the outside in the radial direction and towards the ring 7 in the axial direction.Seated on the control path is the sensing finger 17 which is adjustable both in the axial direction and in the radial direction and is subject to the force of a compression spring 23.

The compression spring 23 acts on a locking lever 24 carrying the sensing finger 17, the compression spring 23 being so inclined in relation to the shaft 5 that the sensing finger 17 is urged towards the control path 21 and the ring 8. The locking lever 24 is stationarily but pivotally mounted on the supporting frame 1 and is adjustable radially and axially.

In the preselection dial 6 there ara sawtooth-shaped withdrawal recesses 25 which have a stop edge 26 in the circumferential direction while the opposite withdrawal slope 27 is so inclined in relation to the shaft 5 and the circumferential direction that it forms a helicoidal surface. There are correspondingly shaped withdrawal projections 28 on the ring 8.

In the position shown in Figure 2, the program drum is at a program starting point in a position of rest. The sensing finger 17 is seated on the control path 21 and the withdrawal projections are in the associated withdrawal recessas 25 so that the ring 8 of the control disc bears against the preselection dial 6 and the ring 7 against the supporting web 29 of the ring 8. As a result, the control laver 14 of the control switch 15 is in the off position in which the high speed for the program drum 4 is switched off.

If the shaft 5 is now turned by hand to allow the working program to be carried out to begin with the main washing operation for axample, then the preselection dial is preferably brought into registar with an associatad detent notch 18 which is associatad with tha program starting point. As a result of tha turning of the preselection dial 6, the withdrawal projection 28, hitherto remaining in its initial position, is displaced in the axial direction towards the program drum 4 over the withdrawal slope 27 (Figure 7). The ring 7 also follows this displacement via the supporting web 29 as a result of which its approach slope 13 urges the control lever 14 radially outwards. As a result of this, the contacts of the control switch 15 are closed and the high speed is switched on for the program drum 4.

On the following adjustment of the program drum 4, the control disc 7, 8 is stepped on through the extensions 11 and the entrainment webs 12 so that the withdrawal projections 28 follow the withdrawal recesses 25.

In the course of this, the withdrawal projections 28 slide on a supporting path 30 which is provided on the end face of the preselection dial 6 adjacent to the program drum 4.

During the axial displacement of the rings 7, 8, a gap 31 is formed between the face path 32 of the cam 21 and the opposite end face 33 of the ring 7. As a result of the oblique position of the compression spring 23, the sensing finger with the locking lever 24 is pressed down from the control path 21 towards the program drum 4 so that the sensing finger 1 7 drops into the gap 31. As soon as the program drum 4, which is still at high speed, has adjusted the control disc 7, 8 to such an extent that the withdrawal projections 28 again enter the associated withdrawal recesses 25, the two rings 7, 8 are at first displaced towards the preselection dial 6. As soon as the ring 7 presses the sensing finger 17 against the face path 32 with its end face 33, the ring 7 stops and the control switch 15 remains closed.During the further stepping on, the ring 8 sinks with its withdrawal projections 28 completely into the withdrawal recesses 25 as a result of which the withdrawal projections 28 come into engagement with the stop edges 26 in each case. From this moment on, the preselection dial 6 is also driven by the program drum 4 until a control notch 22 which is associated with the selected main washing operation comes into coincidence with the sensing finger 1 7. At this moment, as s result of the force of the compression spring 9, the ring 7 presses the sensing finger 17 into the coinciding control notch 22.

Thereupon, the locking of the ring 7 is released and the control lever 14 again slides radially inwards on the approach slope 13. As a result of this, the contacts of the control switch 15 open and switch off the high speed. Since the control notch 22 is precisely associated with the starting point of the main washing operation, the selected program starting point is thus reached.

Accordingly, even if the preselection dial 6 is not adjusted to such an extent that the pawl 20 has dropped into the associated detent notch 18, that is to say the preselection dial 6 has not been set to the precise detent point of the main washing program, an interruption of the high speed is only effected at the program starting point after the sensing finger 17 has there dropped into the associated control notch 22 and the axial displacement of the ring 7 has again been cancelled.

Figure 4 shows the program controller in the position in which it is true that the withdrawal projections 28 have dropped into the withdrawal recesses 25 but the control notch 22 is not yet in axial coincidence with the sensing finger 17. Outside the program startirig points the sensing finger 17 is lifted onto the cam track 21 and is thus in a position to drop once more into the gap 31 which then forms again, on a further adjustment of the preselection dial 6.

It is also possible to construct the rings 7, 8 in the form of a one-piece control disc.

Then this control disc, after a complete axial displacement when the withdrawal projections 28 again run into the associated withdrawal recesses 25, at first only penetrates so deeply into the withdrawal recesses 25 as is rendered possible by the clearance in the axial direction between the sensing finger 17, which has dropped into the gap 31, and the adjacent face path 32 or the end face 33. The withdrawal projection 28 then only comes into engagement with part of the depth of the stop edge 6. The cycle of operation is not altered as a result, however. As soon as the control notch 22 then comes into alignment with the sensing finger 17, however, even this one-piece control disc drops completely into the withdrawal recess 25 with its withdrawal projections 28.

In order to ensure that the follow-up of the program drum is only switched off by the contact travel resulting from the dropping of the sensing finger 17 into the particular control notch 22 of the preselection dial 6, the control switch 15 compriaes a contact bridge 34 which is supported at one end on the control lever 14 via a spring 35 and bears against a supporting contact 36. In addition, the contact bridge 34 bears, in the middle region, loosely against a supporting pin 38 of the control lever 14 with its side remote from the spring 35. The other end of the contact bridge 34 carries the active switch contact and is held by a hook arm 39. The hook arm 39 is part of a two-armed lever 40 which is pivotally mounted in the switch compartment 41 of the control switch 15. The second arm 42 of the lever 40 engages in a fork recess of the control lever 14.If, with the ring 7 undisplaced axially, the control lever 14, as shown in Figure 8, is in a position in which the control switch 15 is not closed, then the hook arm 39 holds the contact bridge 34 so that the control switch 15 is open. In this case, the second arm 42 of this two-armed lever 40 rests freely in the fork recess 43. If the control lever 14 is then adjusted radially outwards, by axial displacement of the ring 7, then at first the supporting pin 38 is detached from the contact bridge 34 but the hook arm 39 still holds the end of the contact bridge at the contact side firmly. Only when the control lever 14 is lifted further does the second arm 42 come into engagement with a wall of the fork recess 43 and pivot tha hook arm 39 to such an extent that it releases the engagement with the contact bridge 34.As a result of this, the contact bridge 34 is abruptly closed by the force of the compression spring 35 and consequently a slow contact making is avoided. The position of the wall of the fork recess 43 is adapted so that the release of the engagement of the hook arm 39 with the contact bridge 34 is only effected when, with the switch contact of the contact bridge 34 bearing against the counter contact, there is a sufficiently great spacing between the contact bridge 34 and the supporting pin 38 of the control lever 14 which spacing is not bridged in the event of a slight movement of the control lever 14 radially inwards, which can be caused, for example, by inaccuracies in shape of the components in engagement or by a partial return movement of the control disc 7/8 as a result of turning the shaft 5 backwards. The closing of the control switch 15 is thus effected with a snap action. If the axial adjustment of the ring 7 is cancelled on alignment of the control notches 22 with the sensing finger 17, then during the restoring of the control lever 14, the free travel between the supporting pin 38 and the contact bridge 34 must first be covered by the lever 14.

(Figure 9). After this travel, however, both the ring 7 and the control lever 14 have reached such a high restoring speed already that the contacts of the control switch are opened abruptly by the further movement. A slow contact making is likewise avoided as a result of this and the burning of the contacts is correspondingly reduced. In addition, assurance is provided that, as a result of the instantaneous switching off, the high speed is also interrupted at the preset moment and so the selected program starting point is reached precisely. In order to keep the possible backward movement of the control disc 7/8 slight after closing of the contact 15 has been effected, the sensing finger 17 must have dropped into the gap 31 between the end face 33 of the individual disc 7 and the face path 32 of the preselection dial 6 at the latest at this moment and must fill this gap as completely as possible. The axial width of the control finger 17 is therefore preferably stepped or increased continuously starting from the tip and fills the gap 31 regardless of the position of the switch point of the contact 15, by dropping in to a greater or lesser extent over a relatively large range of the axial displacement travel.

Claims (9)

1. A manually presettable prcgramme controller, comprising a rotary programme drum arranged to be driven by means of a motor, a rotatable programme preselection dial arranged for manual rotation relatively to said programme drum for presetting a predetermined programme starting position of the programme drum, and a servo-mechanism responsive to rotation of said preselection dial towards a preselected programme setting position, for bringing said programme drum and, if necessary, the programme selection dial to a correspondingly selected starting point, said servomechanism comprising a control switch for actuating said motor to rotate said programme drum, a switch actuating means axially movable relatively to said programme drum but fixed with respect thereto in the direction of rotation and axially biased relatively to said preselection dial said switch actuating means being so arranged to cooperate with said programme selection dial that upon rotary movement of the latter relatively to the programme drum in a direction towards said predetermined starting position said switch actuating means is shifted axially against said bias to actuate said control switch, and an indexing member for retaining said switch actuating means against said bias in the switch actuating position until the programme preselection dial is located in said predetermined starting position, said indexing member comprising a lever having a cam follower which is movable both axially and radially relatively to a cam track associated with said programme selection dial and having radial indexing notches which are open axially towards said switch actuating means, the arrangement being such that upon axial shifting of said switch actuating means against said bias, said cam follower can move axially to fall into a correspondingly formed gap, and thus latch the switch actuating means in the displaced position until the cam follower becomes axialled aligned with and can move axially into a said indexing notch of the cam track.

2. A programme controller as claimed in Claim 1, wherein the switch actuating means comprises two rings of which a first is held on the programme drum for axial displacement and is biased towards the preselection dial by a compression spring, and a second is held for axial displacement in relation to the first and is biased towards the preselection dial by at least one further compression spring, the second ring carrying cam projections by means of which said axial shifting of the actuating means is effected.

3. A programme controller as claimed in Claim 2, wherein the first ring comprises a peripheral ramped cam surface against which a control lever of the control switch bears.

4. A programme controller as claimed in any one of claims 1-3, wherein the arrangement is such that the said axial shifting movement of the switch actuating means is greater than the axial dimension of the cam follower of said lever.

5. A programme controller as claimed in any preceding claim wherein detent notches associated with the preselectable programme starting positions are provided on the preselection dial and can be brought into engagement with a spring-loaded pawl.

6. A programme controller as claimed in any preceding claim, wherein the control switch is constructed in the form of a quickbreak switch with a difference in switching point between the opening point and the closing point.

7. A programme controller as claimed in any preceding claim, wherein the said control switch comprises a control lever arranged to move the switch contacts into the open position, and a locking lever arranged to latch a contact bridge of the control switch in the open position during an initial return closing movement of said control lever, the latter being arranged to actuate said locking lever to release the contact bridge during subsequent return closing movement beyond a position corresponding to the point of opening of the switch contacts.

8. A programme controller as claimed in any preceding claim wherein the axial width of the cam follower increases in the radial outward direction away from said cam track.

9. A programme controller substantially as described herein with reference to the accompanying drawings.