FR2667623A1 - Water jet control device for a washing machine - Google Patents

Abstract

Water jet control device for a washing machine including a slide (COU) the stub (TET) of which is held bearing on the distribution cam (CADI) by a spring (RT) the length (L) of which is kept constant so that the rotational torque of the cam (CADI) remains constant. The length (L) may be kept constant by a means of a controlled moving piece (PMC), the movement of which is controlled by another cam (CACO). The two cams may be synchronous, concentric and integral with each other.

Description

DESCRIPTION "WATER JET CONTROL DEVICE FOR A WASHING MACHINE".

 The present invention relates to a device for controlling the various successive positions of a water jet for a washing machine comprising a plurality of product tanks, each position of the water jet being designed so that the jet exclusively drives the product of the corresponding tank in the washing tub, said device comprising at least holding means for maintaining a positioning control slide bearing on a distribution cam with successive stages.

Washing machines are now well known to the general public; they are automatic and have different trays for washing, rinsing and softening products
A water jet control device is described in patent FR 2 012 899 with a desmodromic cam, that is to say without return spring, and a direct control.

Another kind of control device with return spring and cable control is described in the patents.
FR 2,558,857 and FR 2,288,812.

 The known devices, intended for washing machines comprising a programmer driven by a small stepping motor, all have the drawback that the force required of the stepping motor during the washing cycle is not constant. In addition, certain devices require, at the end of the cycle, additional means for re-initializing the position of the control members of the water jet.

 The present invention aims to eliminate these drawbacks.

 According to the present invention, a control device is particularly remarkable in that the said holding means consist of a holding spring and a controlled movable part, the said holding spring being a tension spring attached by one end to the said slider and by the other end to said controlled movable part, which controlled movable part has a substantially longitudinal movement in the same direction as that of the slider which movement is gradually controlled so that the distance separating the two ends of said spring traction remains substantially constant regardless of the positioning of the water jet.

 Thus, the elongation of the retaining spring being substantially constant, it follows that the friction force exerted on the timing cam is almost constant as is the torque required from the engine.

 Advantageously, the control device comprises a control cam for controlling the movement of said moving part, the profile of said control cam being in regular progressive correspondence with the stepped profile of said distribution cam. Likewise, it is advantageous in this case that said spring for holding the slide bearing on said distribution cam also acts as a spring for maintaining said movable part bearing on said control cam.

 Thus an economy of means of realization is realized, and the friction torque on the control cam is also constant.

 In a preferred embodiment, said distribution cam and said control cam are coaxial and manufactured in a single molded part whose movement is controlled by the programmer of the washing machine.

 As a result, the control device is compact, inexpensive to manufacture and has high operating reliability.

 To avoid blocking positions, in particular when the programmer is manually operated beyond the end of a cycle, it is advantageous for the profile of said control cam to be arranged so that, at the end of each washing cycle, said moving part is released from its support on the cam, and in that the control of the water jet further comprises a return spring for recalling the water jet, the slide, the control spring and said part mobile in their respective initial positions.

 As soon as the "end of cycle" position is reached, either manually or after automatic washing, the entire control device returns to the initial position.

 The present invention will be clearly understood in the light of the non-limiting description of an embodiment illustrated by a single figure.

 The single figure shows the main elements of a water jet control device according to the invention.

On the left side of the figure, a water jet is symbolically represented with its four possible positions JA, JB, JC, JD; it is, for example, similar to the water jet of patent FR 2 558 357, that is to say pivoting and controlled by a CAB cable but this is not a limitation. The cable is controlled by a COU slide, shown in dotted lines for the clarity of the figure. This slide is, for example not limiting, similar to the slide of the patent
FR 2 012 899. The position of the slide is controlled by its TET pin bearing on a CADI distribution cam having a stepped profile which, as shown, is suitable for a machine with three programs PI, P2, P3 for washing times unequal which programs use respectively the positions A, B, C, D, // A, B, D // B, Dil of the water jet; the direction of rotation of the cam is indicated by the arrow F and the length of each arc of the cam corresponds to the duration of each washing step since, generally, the programmer rotates the cam at a constant speed.

The slide is held in abutment on the distribution cam by means of a tension spring RT which is hooked to the slide by its end El and by its end
E2 to a moving part controlled PMC.

The moving part PMC is shown pivoting around the axis AX but its end E2 has a substantially rectilinear longitudinal stroke in the same direction as the slide COU, the moving part PMC could therefore be sliding as well; the movement of the part PMC is controlled by the CACO control cam whose direction of rotation F 'is the same and whose profile is such that the distance' L 'between El and E2 is substantially constant so that the force of RT spring tension is also constant. Thus a constant friction torque is obtained on each of the two cams. The profile of the CACO control cam is clearly progressive unlike the stepped profile of the CADI distribution cam, this difference causes at most only a minimal variation of the distance 'L' since the positions A, B, C, D of the water jet are not very distant from each other and that the CACO profile is designed to "anticipate" on the steps of each program P1 ',
P2 ', P3'.

 Advantageously, the device comprises a return spring RR to return the water jet, the slide, the spring RT and the moving part to the initial position, that is to say as shown, at the end of each program. In all cases the force exerted by the return spring RR is less than the force exerted by the spring RT when the latter has the length 'L' because otherwise the slide, and therefore the water jet, would have an indeterminate floating position. .

 In the figure, the two cams are shown as separate parts having different axes of rotation. According to a preferred embodiment, the two cams are produced in one and the same molded part that a person skilled in the art will easily visualize although this part is not shown in the drawing. Indeed the entanglement of the two cams, if they are superimposed in a flat projection, makes the figure almost illegible. The single piece thus produced is rotated by the programmer and its stepping motor and the water jet control device is then effective and economical.

Claims (5)

1. Device for controlling the different successive positions of a water jet for a washing machine comprising a plurality of product trays, each positioning of the water jet being designed so that the jet exclusively carries the product from the corresponding tray in the washing tub, said device comprising at least holding means for maintaining a positioning control slide bearing on a distribution cam with successive stages characterized in that said holding means consist of a holding spring and of a controlled moving part, the said retaining spring being a tension spring hooked by one end to the said slide and by the other end to the said controlled moving part, which the controlled moving part has a substantially longitudinal movement in the same direction than that of the slide which movement is gradually controlled so that the distance between the two e x ends of said tension spring remains substantially constant regardless of the positioning of the water jet. 2. Control device according to claim 1 characterized in that, it comprises a control cam for controlling the movement of said moving part, the profile of said control cam being in regular progressive correspondence with the stepped profile of the so-called distribution cam. 3. Control device according to claim 2, characterized in that said spring for holding the slider bearing on said distribution cam also acts as a spring for retaining said movable part bearing on said control cam.  4. Control device according to claim 3, characterized in that said distribution cam and said control cam are coaxial and manufactured in a single molded part whose movement is controlled by the programmer of the washing machine. 5. Control device according to claim 2, 3 or 4, characterized in that the profile of said control cam is arranged so that, at the end of each washing cycle, said moving part. is released from its support on the cam, and in that the control of the water jet further comprises a return spring for recalling the water jet, the slide, the control spring and said movable part in their positions respective initials.