EP1403415A2

EP1403415A2 - Device for automatically extracting a dispenser drawer of an electrical household appliance such as a washing machine, and electric household appliance featuring such a device

Info

Publication number: EP1403415A2
Application number: EP03021226A
Authority: EP
Inventors: Dino Chirumbolo
Original assignee: ITW Industrial Components SRL
Current assignee: ITW Industrial Components SRL
Priority date: 2002-09-19
Filing date: 2003-09-18
Publication date: 2004-03-31
Anticipated expiration: 2023-09-18
Also published as: ES2346416T3; EP1403415B1; ITTO20020813A1; DE60332903D1; EP1403415A3

Abstract

A device for automatically extracting from a seat (4) a drawer (3) for dispensing detergent and/or other process fluids of an electric household appliance; the device including a release device (10), elastic means (11) for pushing the drawer from the seat into an extracted position, and decelerating means (12) for opposing the movement of the drawer; wherein the elastic means act on a rotary-to-linear motion conversion device (14) located between the drawer (3) and a fixed member of the seat (4) to produce a linear movement of the seat into the extracted position upon release of the elastic means (11); and wherein the decelerating means act on a rotary member (15) of the rotary-to-linear motion conversion device (14).

Description

The present invention relates to a device for automatically extracting a drawer, in particular a detergent and/or other process fluid dispenser drawer of an electric household appliance, in particular a washing machine; and to an electric household appliance featuring such a device.
As is known, washing machines and other electric household appliances employ detergents and other additives, such as softeners, bleach, etc., which are loaded into a dispenser drawer housed and sliding inside a seat formed on the front panel of the machine. The drawer can be slid manually by the user from a withdrawn position inside the seat, to an extracted position in which it projects from the seat, so that the detergent (liquid or powdered) and other additives or process fluids can be loaded into the drawer from the outside. The drawer is then pushed by the user back into the withdrawn position inside the seat, where it is suspended over the draw tank to draw out the detergent/additives when required by means of a stream of water.
Since the sliding movement of the drawer is currently guided solely by the seat, jamming frequently occurs, both when sliding the drawer in and out, and particularly if the drawer (which is usually fitted with a handle) is not gripped properly by the user. Moreover, since the limit stops, if any, are click-on types, which are easily exceeded by excessive pull on the drawer, the drawer may even be accidentally detached altogether from the seat; in which case, reinsertion of the drawer inside the seat may prove awkward.
It is an object of the present invention to eliminate the aforementioned drawbacks by providing an automatic drawer extracting device, which allows the user to operate the drawer easily and effortlessly with one hand and with no risk of jamming, and which at the same time is compact, highly reliable and cheap to produce and assemble.
According to the present invention, there is provided a device for automatically extracting a drawer which slides inside a seat between an extracted position, in which the drawer projects from the seat, and a withdrawn position, in which the drawer is housed inside the seat, substantially flush with a mouth of the seat; said drawer being, in particular, a drawer for dispensing process fluids of an electric household appliance; and the device comprising a release device; elastic means for pushing the drawer from the withdrawn position to the extracted position; and decelerating means for opposing the sliding movement of the drawer inside the seat; said device being characterized by also comprising a reversible rotary-to-linear motion conversion device; said elastic means and said decelerating means acting on a rotary member of said reversible rotary-to-linear motion conversion device; and the reversible rotary-to-linear motion conversion device being located between said drawer and a fixed member of said seat, so that movement of the drawer from the extracted position to the withdrawn position takes place in opposition to said elastic means, whereas operation of said release device produces a linear movement of the drawer from the withdrawn position to the extracted position as a consequence of the action of said elastic means.
The release device is preferably a push-push type.
As such, the drawer is slowly opened automatically by the user simply pressing lightly on the front panel, and is closed by pushing it, again from the front, inside the seat in opposition to the elastic opening means, to engage the release device in a lock configuration which keeps the drawer closed in the correct position. The closing movement, however, is guided by the motion transmission device used to open the drawer automatically, thus also preventing the drawer from jamming when being closed; and the user is prevented from exceeding the established limit positions, which are controlled by the limit stops of the push-push release device.
A non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which:

Figure 1 shows a schematic, partly exploded, three-quarter front view in perspective of the device according to the invention;
Figure 2 shows a three-quarter rear view of the Figure 1 device assembled;
Figure 3 shows a section of a detail of the Figure 1 and 2 device;
Figure 4 shows a schematic side section of an electric household appliance featuring the Figure 1-3 device.

With reference to Figures 1 to 4, number 1 indicates as a whole an electric household appliance - in the example shown, a washing machine - equipped with a device 2 for automatically extracting a dispenser drawer 3 from a seat 4. More specifically, drawer 3 is a drawer for dispensing detergent and other process fluids (softener, bleach, etc.), and which is extracted for loading from seat 4 through a mouth 5 of seat 4 formed on a front panel 7 of machine 1. Underneath drawer 3, seat 4 has a known draw tank 6, by which the detergent and other washing additives are drawn, in use, from separate known compartments (not shown for the sake of simplicity) of drawer 3 by a stream of water.
By means of device 2, drawer 3 slides inside seat 4 between an extracted position (not shown), in which it projects from seat 4 and front panel 7, and a withdrawn position (Figure 4) in which drawer 3 is housed inside seat 4, substantially flush with mouth 5 and over tank 6.
Device 2 comprises a release device 10, shown partly in Figure 1; elastic means 11 for pushing drawer 3 from the withdrawn position to the extracted position; and decelerating means 12 for opposing the sliding movement of drawer 3 inside seat 4. According to the invention, device 2 also comprises a reversible rotary-to-linear motion conversion device 14, and is designed so that elastic means 11 and decelerating means 12 both act, directly or indirectly, on a rotary member 15 of device 14; and device 14 is located between drawer 3 and a fixed member of seat 4, defined by tank 6, so that movement of drawer 3 from the extracted position to the withdrawn position always takes place in opposition to elastic means 11, whereas operation of release device 10 produces, as described later, a linear movement of drawer 3 from the withdrawn position to the extracted position as a consequence of the action of elastic means 11.
In the non-limiting example shown, reversible rotary-to-linear motion conversion device 14 is a rack-and-pinion mechanism, and rotary member 15 is defined by a gear housed for rotation inside a casing 16 (Figures 2 and 3) and which meshes with a rack 18, outside casing 16, through a window 19 formed through casing 16. In the example shown, casing 16 is integral with tank 6, in which it is housed just beneath drawer 3 and close to mouth 5, while rack 18 is integral with and located beneath drawer 3. Obviously, the above arrangement may be inverted, so that rack 18 is integral with tank 6 and located beneath drawer 3, which is fitted integrally underneath with casing 16. The only essential point being that gear 15 meshes with rack 18, and is integral with a member other than that supporting rack 18.
Casing 16 comprises two half- shells 20, 21, at least one of which (in the example shown, both) is cup-shaped. Gear 15 is fitted idly to half-shell 20, is mounted to project towards half-shell 21 by means of a cylindrical shaft 23 (Figure 3) engaging a seat 24 formed on the concave side of half-shell 20, and comprises a cup-shaped body 25 having an inner concavity 26 facing half-shell 21 in use. A number of pins 27, arranged in a ring, project from half-shell 21 towards half-shell 20 and inside concavity 26 of gear 15 when half- shells 20 and 21 are assembled. Half-shell 21 is preferably also provided, radially outwards of pins 27, with a collar 29, which, in use, penetrates concavity 26 and acts, when necessary, as a support and/or guide for gear 15, which is otherwise mounted to project freely.
Elastic means 11 comprise a helical spring packed between half-shell 21 and concavity 26 of gear 15, and housed entirely inside concavity 26. Spring 11 comprises a first end 31 engaging and angularly integral with gear 15; and a second end 32 which, when half- shells 20 and 21 are assembled, engages one of pins 27 so as to be angularly integral with casing 16. More specifically, spring 11 is fitted to a hub 33 (Figure 3) coaxial with the axis of rotation of gear 15, and which projects inside concavity 26, on the opposite side to half-shell 20, and is substantially defined by an extension of shaft 23 inside concavity 26. Hub 33 has a diametrical slot 34 engaged by end 31 of the spring, which is bent radially towards the axis of symmetry of spring 11.
Half- shells 20, 21 click together by means of known fastening means, and are molded from synthetic plastic material, like all the other component parts of device 2, including casing 16, gear 15, and rack 18. Decelerating means 12 are defined by a known rotary oil-bath decelerator comprising a fluidtight body 42 filled with silicone oil and fixed integrally inside casing 16, beneath gear 15 (and therefore on the opposite side to window 19); and a rotary member 43 (Figure 3), which rotates with a high degree of resistance inside the oil in body 42, and projects in fluidtight manner from one side of body 42.
According to one aspect of the invention, rotary member 43 is connected to mesh indirectly with gear 15 by means of a toothed transmission comprising a pinion 44 fitted angularly integral to rotary member 43 and meshing with a pinion 45 formed in one piece with body 25, on the opposite side to concavity 26, and angularly integral with shaft 23. Consequently, since pinion 45 is much smaller than gear 15, the number of revolutions of gear 15 is also reduced with respect to those of rotary member 43.
Release device 10 is located close to mouth 5, acts directly on drawer 3 according to one aspect of the invention, and is preferably a push-push type.
More specifically, release device 10 comprises a block 50, a bottom face of which supports a positive track 51 formed, according to a further aspect of the invention, in one plane; and a pin 52 supported by a leaf spring 53, which is flexible in a plane perpendicular to the axis of pin 52 and parallel to the single plane of positive track 51. Leaf spring 53 is carried integrally in one piece with casing 16, and projects from casing 16 towards mouth 5 of seat 4; and positive track 51 is integral with rack 18, block 50 being fixed, together with rack 18, to a bottom face of drawer 3, close to a front surface of drawer 3 which is substantially flush with front panel 7 when drawer 3 is in the withdrawn position inside sear 4.
Single-plane positive track 51 comprises (Figure 1) two branches 61, 62; a tooth 63; and an inclined stop surface 64 opposite tooth 63 and between branches 61 and 62.
In actual use, when drawer 3 is in the withdrawn position, pin 52 engages tooth 63 and keeps drawer 3 in the withdrawn position in opposition to spring 11, which is preloaded to exert torque on gear 15 by means of end 31. To open drawer 3, the user simply pushes lightly on the front surface of drawer 3, flush with front panel 7, to overcome the resistance of spring 11. The resulting slight withdrawal movement of drawer 3 inside seat 4 produces a relative movement between pin 52 (which remains stationary, by being secured to tank 6 by casing 16) and tooth 63 (which withdraws with drawer 3), thus releasing pin 52, which comes to rest against inclined stop surface 64.
This laterally flexes leaf spring 53, so that pin 52 engages branch 61 of positive track 51, thus fully releasing drawer 3; spring 11 is therefore free to rotate gear 15 and so produce a linear movement of rack 18, which takes drawer 3 with it; and the rotation direction imposed by the preload on spring 11 is such as to move drawer 3 into the extracted position, during which movement, pin 52 slides along branch 61.
Once the preload of spring 11 is exhausted, drawer 3 is arrested in the desired extracted position. To close drawer 3, the user simply pushes once more on the front surface of the drawer to push the drawer back into the withdrawn position inside seat 4. The inverse movement of drawer 3 produced manually by the user rotates gear 15 by means of rack 18 to overcome the resistance of, and again begin preloading, spring 11, end 32 of which is locked angularly integral with stationary casing 16, and end 31 of which rotates together with gear 15 to twist and so preload spring 11.
As drawer 3 withdraws, pin 52 moves relatively, in the opposite direction to before, along branch 62 which is inclined, to which pin 52 is transferred by the springback of leaf spring 53 at the end of the extraction travel of drawer 3, as soon as pin 52 disengages branch 61. Given the slope of branch 62, the above movement flexes leaf spring 53 laterally in the opposite direction to before, so that, as soon as pin 52 disengages branch 62 as drawer 3 reaches the withdrawn position, pin 52 clicks onto tooth 63 to lock drawer 3 in the withdrawn position in opposition to the now fully preloaded spring 11.

Claims

A device for automatically extracting a drawer which slides inside a seat between an extracted position, in which the drawer projects from the seat, and a withdrawn position, in which the drawer is housed inside the seat, substantially flush with a mouth of the seat; said drawer being, in particular, a drawer for dispensing process fluids of an electric household appliance; and the device comprising a release device; elastic means for pushing the drawer from the withdrawn position to the extracted position; and decelerating means for opposing the sliding movement of the drawer inside the seat; said device being characterized by also comprising a reversible rotary-to-linear motion conversion device; said elastic means and said decelerating means acting on a rotary member of said reversible rotary-to-linear motion conversion device; and the reversible rotary-to-linear motion conversion device being located between said drawer and a fixed member of said seat, so that movement of the drawer from the extracted position to the withdrawn position takes place in opposition to said elastic means, whereas operation of said release device produces a linear movement of the drawer from the withdrawn position to the extracted position as a consequence of the action of said elastic means.
A device as claimed in claim 1, characterized in that said reversible rotary-to-linear motion conversion device is a rack-and-pinion mechanism; said rotary member being defined by a gear housed for rotation inside a casing and which meshes with a rack, outside the casing, through a window formed through the casing; said casing being carried integrally by said fixed member of said seat, and said rack being carried integrally by and beneath said drawer, or vice versa.
A device as claimed in Claim 2, characterized in that said casing comprises two half-shells, at least one of which is cup-shaped; a first half-shell idly supporting said gear, which is mounted to project towards the second half-shell, and comprises an inner concavity facing the second half-shell; and the second half-shell having, projecting towards said first half-shell, a number of pins arranged in a ring, and which project inside said concavity of the gear when the half-shells are assembled.
A device as claimed in Claim 3, characterized in that said elastic means comprise a helical spring packed between said second half-shell and said concavity of the gear, and housed entirely inside the concavity; said spring having a first end engaging and angularly integral with the gear, and a second end engaging one of said pins, when the half-shells are assembled, so as to be angularly integral with the casing.
A device as claimed in Claim 4, characterized in that said spring is fitted to a hub coaxial with the axis of rotation of said gear and projecting inside said concavity of the gear, on the opposite side to said first half-shell; the hub having a slot engaged by said first end of the spring, which is bent radially towards the axis of symmetry of the spring.
A device as claimed in one of Claims 2 to 5, characterized in that said half-shells click together.
A device as claimed in any one of the foregoing Claims, characterized in that said release device is located close to said mouth, and acts directly on said drawer.
A device as claimed in Claim 7, characterized in that said release device is a push-push type.
A device as claimed in Claim 8, characterized in that said release device comprises a positive track formed in one plane; and a pin carried by a leaf spring flexible in a plane perpendicular to said pin and parallel to said one plane of the positive track.
A device as claimed in Claim 9, characterized in that said leaf spring is carried integrally in one piece with said casing, and said positive track is integral with said rack.
A device as claimed in one of the foregoing Claims, characterized in that said decelerating means consist of a rotary oil-bath decelerator fixed integrally to and inside said casing, and a rotary member of which is connected to mesh with said gear by means of a toothed transmission.
An electric household appliance, in particular a washing machine, characterized by comprising a device for automatically extracting a drawer which slides inside a seat, as claimed in one of the foregoing Claims, wherein said drawer is a detergent dispenser drawer, and said fixed member of said seat is a detergent draw tank.