GB2287176A

GB2287176A - Kitchen machine drive mechanism.

Info

Publication number: GB2287176A
Application number: GB9502349A
Authority: GB
Inventors: Johan Ronald Nijzingh; Adam Weits
Original assignee: Philips Electronics NV
Current assignee: Koninklijke Philips NV
Priority date: 1994-02-09
Filing date: 1995-02-07
Publication date: 1995-09-13
Also published as: GB9502349D0; DE29501484U1; FR2715819A3; FR2715819B3

Abstract

A kitchen machine having a base (3) and a motor housing (5) which is arranged on the base (3) and in which an electric motor (27) is accommodated. On the base (3) next to the motor housing (5), an open bowl (9) can be placed, supported with rotation possibility relative to the base (3). A transverse arm (17) can be coupled on the motor housing (5), extending to above the bowl (9). A tool (19) can be placed in the bowl (9) and coupled to a transmission (25) which is arranged in the transverse arm (17) and driven by the electric motor (27). The bowl (9) can be driven into rotation by a pinion (21) also coupled to the transmission (25). The transmission (25) can be coupled to the electric motor (27) via a coupling part (29) of the motor housing (5) and a coupling part (31) of the transverse arm (17). The coupling part (29) comprises a number of slots (87) separated by partition walls (85), while the coupling part (31) has a number of tongues (71) which mate with the slots (87). When the transverse arm (17) is placed on the motor housing (5), the tongues (71) are centred relative to the coupling part (29) by means of a tapering centring portion (91) of the coupling part (29), while the tongues (71) are aligned with the slots (87) by means of alignment studs (93). In a special embodiment of the invention, the coupling part (29) has an even number of alignment studs (93), one alignment stud (93) being positioned adjacent one of the partition walls (85) of each pair of partition walls (85) adjacent one another. In this manner the coupling parts (29, 31) can be used in a kitchen machine in which the transverse arm (17) can be coupled to the motor housing (5) in a pivoting movement. <IMAGE>

Description

KITCHEN MACHINE The invention relates to a kitchen machine having a housing in which an electric motor is arranged, and having an attachment which can be coupled to the housing and in which a tool can rotate when driven by the electric motor, said attachment comprising a coupling part for engagement with a coupling part which belongs to the housing and can be driven by the electric motor, one of said coupling parts being provided with a number of tongues for cooperation with a number of slots of the other coupling part which mate with the tongues and are mutually separated by partition walls, while one of the coupling parts is provided with means for centring and aligning the tongues relative to the slots during the process of coupling of the attachment to the housing.

The invention also relates to a coupling with two coupling parts suitable for use in a kitchen machine according to the invention.

The invention also relates to a coupling part suitable for use in a kitchen machine according to the invention.

A kitchen machine of the kind mentioned in the opening paragraph is known from European Patent 0 115 367. The attachment of the known kitchen machine is a vegetable cutter which can be driven by the electric motor of a hand mixer which can be coupled to the vegetable cutter. The coupling part of the hand mixer comprises a coupling bush whose inner wall is provided with a number of radial slots, while the coupling part of the vegetable cutter is provided with a further coupling bush and a round shaft which is slidable in the further coupling bush, which is provided with tongues corresponding to said slots, and which rests on a helical spring arranged in the further coupling bush. The round shaft is guided in two helical recesses in an inner wall of the further coupling bush by means of two projections.When the attachment is placed on the housing, the two coupling parts come into pressure contact with one another. If the coupling between the two coupling parts is not achieved immediately, the round shaft is so rotated relative to the further coupling bush that the round shaft aligns itself with the coupling bush of the hand mixer, whereby the coupling is achieved. A self-locating coupling is thus provided, while a user of the kitchen machine need only ensure that the two coupling parts are approximately in one another's extension.

A disadvantage of the known kitchen machine is that a drive torque exerted by the electric motor on the coupling bush of the hand mixer is transmitted through said round shaft and said projections to the further coupling bush of the vegetable cutter under elastic aeformation of said helical spring, so that the projections and the helical spring are subject to a comparatively strong mechanical load. The strong mechanical load may lead to wear or damage of the projections, the helical recesses, and the helical spring, as a result of which the operation of the coupling parts may deteriorate.

It is an object of the invention to provide a kitchen machine of the kind mentioned in the opening paragraph which is provided with reliable, self-locating coupling parts and in which the above disadvantages are counteracted as much as possible.

The invention is for this purpose characterised in that said means comprise at least one rounded alignment stud which is provided near one of the partition walls on a tapering centring portion of the coupling part provided with the slots. When the attachment is placed on the housing, the coupling parts are mutually centred relative to a common axis of rotation of the coupling parts through cooperation of the tongues and the tapering centring portion. When one of the tongues comes into the vicinity of the partition wall present near said alignment stud during this, and the relevant tongue as a result cannot slide into one of the slots adjoining the relevant partition wall, this tongue comes into contact with the alignment stud, so that the coupling parts are mutually rotated and the tongue can pass the alignment stud and the partition wall.The tongues and slots are thus centred relative to the axis of rotation by the tapering centring portion and subsequently aligned in a direction parallel to the axis of rotation by the alignment stud. A reliable self-locating coupling is provided thereby which comprises a minimum number of components and can be manufactured in a simple manner. The tapering centring portion and the alignment stud are not loaded by the torque of the electric motor during operation, so that the wear of the centring portion and alignment stud is minimal.

A special embodiment of a kitchen machine according to the invention is characterised in that the coupling part provided with tongues belongs to the attachment and is freely journalled relative to the attachment in the rotation direction. Since the said coupling part is freely journalled relative to the attachment in the rotation direction, the coupling part can be rotated and aligned relative to the other coupling part through cooperation of the tongues with the alignment stud of the other coupling part when the attachment is being placed on the housing, the other coupling part not being freely journalled in the rotation direction owing to its coupling to the electric motor.

A further embodiment of a kitchen machine according to the invention, in which the coupling parts comprise an even number of tongues and slots, is characterised in that an alignment stud is positioned near one of the partition walls of each pair of partition walls situated next to one another. It is achieved thereby that the coupling parts can also be coupled when the attachment is pivotable relative to the housing and can be placed on the housing by means of a pivoting movement. When the attachment is placed on the housing in a pivoting movement, one of the tongues comes into contact with the tapering centring portion, so that the two coupling parts are mutually rotated and also an adjacent tongue comes into contact with the centring portion.Since an alignment stud is positioned near one of the partition walls of each pair of partition walls situated next to one another, one of the said adjoining tongues will come into contact with the alignment stud, whereby the coupling parts are correctly maligned.

A yet further embodiment of a kitchen machine according to the invention is characterised in that one of the partition walls of each pair of partition walls situated next to one another is shorter than the other partition wall of the pair seen in a direction parallel to an axis of rotation of the relevant coupling part. If the partition walls are equally long in a direction parallel to the axis of rotation and the attachment has a comparatively small pivoting radius, the two adjoining tongues which come into contact with the centring portion first may slide past the sides of the relevant adjoining partition walls facing away from one another, so that neither of the said tongues enters the slot present between the relevant partition walls and the coupling parts cannot be coupled.

Since one of the partition walls of each pair of partition walls situated next to one another is shorter in a direction parallel to the axis of rotation, it is achieved that the short partition wall is not passed by the relevant tongue until after the attachment is substantially at the end of its pivoting movement and the adjoining tongue has already been correctly placed in the adjoining slot.

A special embodiment of a kitchen machine according to the invention, in which the partition walls each extend along a centreline of the relevant coupling part and have a bevelled edge, is characterised in that the alignment stud is arranged at a side of the partition wall which is bounded by an upper line of the bevelled edge. When a tongue comes into contact with said alignment stud, the tongue and said partition wall are so rotated relative to one another that the tongue drops either into the slot adjoining said side or into the slot adjoining the other side of said partition wall via the bevelled edge.

A further embodiment of a kitchen machine according to the invention, in which the tongues are eminently suitable for cooperation with the rounded alignment stud and the bevelled edges of the partition walls, is characterised in that the tongues have bevelled, rounded ends.

The invention is explained in more detail below with reference to the drawing, in which Fig. la diagrammatically shows a kitchen machine according to the invention with a rotatable open bowl and a transverse arm, Fig. 1b shows the kitchen machine of Fig. la with a number of detachable parts, Fig. 2a diagrammatically shows the kitchen machine of Fig. la, the open bowl being replaced by a further bowl with a lid, while the transverse arm has been replaced by a blender, Fig. 2b shows the kitchen machine of Fig. 2a with a number of detachable parts, Fig. 3a shows a coupling part of the transverse arm of the kitchen machine of Fig. la and of the blender of the kitchen machine of Fig. 2a, Fig. 3b is a bottom view of the coupling part of Fig. 3a, Fig. 4a shows a coupling part of a motor housing of the kitchen machine of Fig. la or 2a, Fig. 4b is a plan view of the coupling part of Fig. 4a, Fig. Sa shows the coupling parts of the motor housing and the transverse arm of the kitchen machine of Fig. la with the transverse arm being hinged relative to the motor housing, Fig. 5b shows an incorrect coupling between the coupling parts of Fig.

5a, Fig. 6a shows an alternative coupling part for the motor housing of the kitchen machine of Fig. la or 2a, and Fig. 6b is a plan view of the alternative coupling part of Fig. 6a.

The kitchen machine shown in Figs. la and 1b is provided with a synthetic resin housing 2 which comprises a base 3 and a motor housing 5 arranged on the base 3. The base 3 is provided with a number of feet 7 with which the kitchen machine can be placed on a surface. An open synthetic resin bowl 9 can be placed on the base 3 next to the motor housing 5. A bearing bush 13 is provided below a bottom 11 of the bowl 9, by means of which bush the bowl 9 is supported with rotation possibility relative to a circular-cylindrical guide 15 provided on the base 3.

As is further shown in Figs. la and lb, a detachable transverse arm 17 which extends substantially parallel to the base 3 above the open bowl 9 is present on the motor housing 5. In the bowl 9 there is a rotatable tool 19 such as, for example, a mixing tool shown in Figs. la and lb, detachably coupled to the transverse arm 17. A pinion 21 journalled in the transverse arm 17 is in engagement with a toothed rim 23 provided along an outer circumference of the bowl 9. The tool 19 and the pinion 21 are coupled to a transmission 25, shown diagrammatically only in Fig. la, which is arranged in the transverse arm 17 and can be driven by an electric motor 27 accommodated in the motor housing 5.When the transverse arm 17 is placed on the motor housing 5, a first coupling part 29 which has rotation bearings relative to the motor housing 5 and can be driven by the electric motor 27 comes into engagement with a second coupling part 31, which has rotation bearings relative to the transverse arm 17 and is also coupled to the transmission 25. The coupling parts 29 and 31 shown diagrammatically only in Fig. la will be explained in more detail below. The tool 19 can thus be rotated in the bowl 9 by means of the electric motor 27, while the bowl 9 can be rotated relative to the base 3 by means of the electric motor 27.

As is further shown in Figs. 2a and 2b, a further transparent bowl 33 may be placed on the base 3 instead of the open bowl 9, while a transparent blender 35 may be placed on the motor housing 5 instead of the transverse arm 17, so that the kitchen machine can be used in various assemblies. The further bowl 33 can be closed with a lid 37 provided with a feed tube 39 and can be locked to the base 3 by means of studs 41 cooperating with slots 43 provided in the guide 15. A tool 45 can rotate in the further bowl 33, for example, a cutting tool shown in Figs. 2a and 2b, which tool can be exchanged after the removal of the lid 37. The tool 45 has rotation bearings relative to the further bowl 33 by means of a bush-shaped shaft 47, which is present around a central tube 49 of the further bowl 33, and a bearing bush 51 provided at the lid 37.

When the further bowl 33 is placed on the base 3, the tool 45 is coupled to a coupling bush 53 which has its rotation bearings in the guide 15 and can be driven by the electric motor 27 via a transmission 55 arranged in the base 3 and shown diagrammatically only in Fig. 2a. The transparent blender 35 is provided with a lid 57 and a synthetic resin bottom part 59 which can be locked with four studs 61 in four slots 63 of the motor housing 5 cooperating with said studs. A tool 65, for example a mixing tool shown in Fig. 2a, has its rotation bearings in the bottom part 59 of the blender 35. In contrast to the tool 45 which can be placed in the further bowl 33, the tool 65 is not exchangeably fastened in its bearings in the bottom part 59 of the blender 35.The blender 35 further comprises a second coupling part 67 shown diagrammatically only in Fig. 2a and connected to the tool 65, identical to the second coupling part 31 of the transverse arm 17 shown in Figs. la and lb. When the blender 35 is placed on the motor housing 5, the second coupling part 67 comes into engagement with said first coupling part 29 of the motor housing 5, so that the tool 65 can be driven by the electric motor 27 via the coupling parts 29 and 67.

As Figs. 3a and 3b show, the identical coupling parts 31 and 67 of the transverse arm 17 and the blender 35 each comprise a disc-shaped carrier 69 which is coupled to the transmission 25 of the transverse arm 17 and to the tool 65 of the blender 35, respectively. Six tongues 71 are fastened on the carrier 69, arranged in a circle and extending parallel to an axis of rotation 73 of the coupling part 31, 67. As Figs. 3a and 3b further show, the tongues 71 each have a bevelled, rounded end 75.

As Figs. 4a and 4b show, the coupling part 29 of the motor housing 5 has a central shaft 77 and a bush 79, the central shaft 77 being coupled to an output shaft 81 of the electric motor 27, while the central shaft 77 and the bush 79 are positioned concentrically relative to an axis of rotation 83 of the coupling part 29. As Fig. 4b shows, six radial partition walls 85 are arranged between the central shaft 77 and the bush 79 at regular interspacings, six slots 87 being defined by the central shaft 77, the bush 79, and the partition walls 85. As is visible in Fig. 4a, the partition walls 85 each have a bevelled edge 89. The coupling part 29 further comprises near an end of the central shaft 77 a tapering centring portion 91 which is also arranged concentrically relative to the central shaft 77 and the bush 79.Three rounded alignment studs 93 are so provided on the tapering centring portion 91 that the partition walls 85 alternately adjoin one of the alignment studs 93, an alignment stud 93 thus being positioned near one of the partition walls 85 of each pair of partition walls 85 situated adjacent one another. As is visible in Fig. 4b, each alignment stud 93 is positioned at a side of the relevant partition wall 85 which is bounded by an upper line 95 of the bevelled edge 89.

The coupling parts 29 and 67 of the motor housing 5 and of the blender 35 cooperate as follows. When the blender 35 is placed on the motor housing 5, the studs 61 are inserted into the slots 63 of the motor housing 5, whereby the coupling parts 29 and 67 come into mutual contact. The tongues 71 of the coupling part 67 are then centred by the tapering centring portion 91 of the coupling part 29 relative to the axis of rotation 83 of the coupling part 29, so that the axes of rotation 73 and 83 of the coupling parts 67 and 29 are aligned. If the six tongues 71 happen to be exactly in line with the six slots 87, the tongues 71 will immediately enter the slots 87 and the coupling between the coupling parts 29 and 67 will be achieved immediately, after which the blender 35 can be locked in the slots 63 with a small rotary movement.If the tongues 71 are not aligned relative to the slots 87, three tongues 71 will make contact with the three alignment studs 93. Since the coupling part 67 with the tool 65 is freely journalled relative to the blender 35 in the rotation direction, the coupling part 67 is rotated relative to the coupling part 29 through cooperation between the tongues 71 and the alignment studs 93, so that the tongues 71 can pass the alignment studs 93. The tongues 71 then slide either along the bevelled edges 89 of the partition walls 85 into the slots 87 which are bounded by the sides of the partition walls 85 adjoining the bevelled edges 89, or slide directly into the slots 87 which are bounded by the other sides of the partition walls 85, whereby the coupling between the coupling parts 29 and 67 is achieved.In this manner the tongues 71 of the coupling part 67, the slots 87 of the coupling part 29, and the axes of rotation 73 and 83 of the coupling parts 29 and 67 are centred relative to one another by means of the tapering centring portion 91, while the tongues 71 and the slots 87 are subsequently brought into line by means of the alignment studs 93. A reliable, self-locating coupling between the motor housing 5 and the blender 35 is provided thereby, it being sufficient for a user of the kitchen machine to bring the coupling parts 29 and 67 approximately in line only in that the studs 61 of the blender 35 are introduced into the slots 63 of the motor housing 5.Since the coupling parts 29 and 67 can each be manufactured in a simple and inexpensive manner as a single component by means of, for example, injection moulding, the coupling comprises a minimum nllmber of components. It is further noted that m operation the mechanical torque of the electric motor 27 is transmitted to the tongues 71 of the coupling part 67 via the partition walls 85 of the coupling part 29, so that the alignment studs 93 and the centring portion 91 are not loaded during operation and accordingly are subject to only minimum wear.

When the transverse arm 17 is placed on the motor housing 5 in the position shown in Fig. Ib, the mutual cooperation of the coupling parts 29 and 31 of the motor housing 5 and transverse arm 17 is identical to the cooperation between the coupling parts 29 and 67 of the motor housing 5 and the blender 35 as described above.

As Fig. 1b shows, the transverse arm 17 is provided with a locking member 97 with which the transverse arm 17 can be locked to the motor housing 5. The locking mechanism 97 for this purpose comprises four studs 99 which can be rotated relative to the transverse arm 17 by means of a knob 101. It is noted that only two of the four studs 99 are visible in Fig. lb. When the transverse arm 17 is placed on the motor housing 5, the studs 99 are placed in the slots 63 of the motor housing 5, after which the transverse arm 17 is locked to the motor housing 5 through rotation of the studs 99 by means of the knob 101.

When the transverse arm 17 is coupled to the motor housing 5, the transverse arm 17 is pivotable relative to the locking member 97 locked to the motor housing 5 about a pivot axis 103 diagrammatically shown in Fig. la. The tool 19 or the bowl 9 may thus be exchanged or cleaned without unlocking of the transverse arm 17 from the motor housing 5. When the transverse arm 17 is pivoted towards the motor housing 5, the coupling parts 29 and 31 come into a position shown in Fig. 5a where the tongues 71 of the coupling part 31 are already in contact with the centring portion 91 of the coupling part 29 when the pivot angle a is not yet zero.As Fig. 5a shows, the tongue 71a first makes contact with the centring portion 91, whereby the coupling part 31 is rotated relative to the coupling part 29 and also the adjoining tongue 71b comes into contact with the centring portion 91. If the tongues 71 a and 71b happen to be exactly aligned relative to the slots 87a and 87b, the tongues 71a and 71b will slide immediately into the slots 87a and 87b, after which also the remaining tongues 71 will enter the slots 87 and the coupling between the coupling parts 29 and 31 is achieved immediately.If the tongues 71a and 71b are not exactly aligned relative to the slots 87a and 87b, one of the tongues 71a, 71b will come into contact with one of the three alignment studs 93, because an alignment stud 93 is positioned near one of the partition walls 85 of each pair of adjacent partition walls 85. The coupling part 31 is then rotated relative to the coupling part 29 through cooperation between the relevant tongue 71a, 71b and the relevant alignment stud 93, so that the tongues 71a, 71b and subsequently also the remaining tongues 71 can enter the slots 87. Thus the tongues 71 and the slots 87 are also correctly aligned with one another when the transverse arm 17 is coupled to the motor housing 5 by means of a pivoting movement.

When the transverse arm 17 is coupled to the motor housing 5 in a pivoting movement, the tongues 71a and 71b will come into contact with the partition walls 85 near the central shaft 77 of the coupling part 29, as is visible in Fig. Sa. If the pivot radius R of the pivoting movement is comparatively small, the tongues 71a and 71b may slide along the sides of the relevant adjoining partition walls 85 which face away from one another, as shown in Fig. Sb, so that the coupling parts 29 and 31 cannot become coupled any further. Figs. 6a and 6b show an alternative coupling part 105 for the motor housing 5 with which the incorrect coupling described above is avoided.As is visible in Figs. 6a and 6b, the alternative coupling part 105 differs from the coupling part shown in Figs. 4a and 4b in that one of the partition walls 107a of each pair of partition walls 107a, 107b situated next to one another is shorter than the other partition wall 107b in a direction parallel to an axis of rotation 109 of the coupling part 105. Since the partition walls 107a are shorter than the partition walls 107b, the relevant tongue 71a, 71b will first pass the partition wall 107b. The shorter partition wall 107a is not passed by the adjoining tongue 71a, 71b until the transverse arm 17 is substantially at the end of the pivoting movement and the pivot angle a is negligibly small, so that said adjoining tongue 71a, 71b can correctly pass the shorter partition wall 107a near the bush 79. The coupling parts 31, 105 thus provide a correct and reliable coupling between the motor housing 5 and the transverse arm 17 also in the case of a comparatively small pivot radius R.

The kitchen machine described above comprises a motor housing 5 which is positioned on a base 3 and in which the electric motor 27 is accommodated, while the bowl 9 can be placed next to the motor housing 5. It is noted that the invention is also applicable to kitchen machines having a different arrangement or different attachments such as, for example, a kitchen machine in which the transmission can be driven by the electric motor of a hand mixer which can be placed on the transverse arm. The invention is also applicable to a kitchen machine having an attachment which cannot pivot but can be removed, or can pivot but cannot be removed.

In the kitchen machine described above, the coupling part 29 of the motor housing 5 is provided with the slots 87, the centring portion 91, and the alignment studs 93, while the coupling part 31, 67 of the attachment 17, 35 is provided with the tongues 71. It is noted that the invention also applies to a kitchen machine in which the tongues belong to the coupling part of the housing and the slots to the coupling part of the attachment.

It is finally noted that instead of the three alignment studs 93 only a single alignment stud need be used if the attachment is not pivotable and can be coupled to the housing in one position only. An odd number of tongues and slots may also be used then. When a pivotable attachment is used, an odd number of slots and tongues may also be used, at least one alignment stud being positioned near each pair of partition walls situated next to one another.

Claims

CLAIMS:

1. A kitchen machine having a housing in which an electric motor is arranged, and having an attachment which can be coupled to the housing and in which a tool can rotate when driven by the electric motor, said attachment comprising a coupling part for engagement with a coupling part which belongs to the housing and can be driven by the electric motor, one of said coupling parts being provided with a number of tongues for cooperation with a number of slots of the other coupling part which mate with the tongues and are mutually separated by partition walls, while one of the coupling parts is provided with means for centring and aligning the tongues relative to the slots during the process of coupling of the attachment to the housing, characterised in that said means comprise at least one rounded alignment stud which is provided near one of the partition walls on a tapering centring portion of the coupling part provided with the slots.

2. A kitchen machine as claimed in Claim 1, characterised in that the coupling part provided with tongues belongs to the attachment and is freely journalled relative to the attachment in the rotation direction.

3. A kitchen machine as claimed in Claim 1 or 2, in which the coupling parts comprise an even number of tongues and slots, characterised in that an alignment stud is positioned near one of the partition walls of each pair of partition walls situated next to one another.

4. A kitchen machine as claimed in Claim 3, characterised in that one of the partition walls of each pair of partition walls situated next to one another is shorter than the other partition wall of the pair seen in a direction parallel to an axis of rotation of the relevant coupling part.

5. A kitchen machine as claimed in any one of the preceding Claims, in which the partition walls each extend along a centreline of the relevant coupling part and have a bevelled edge, characterised in that the alignment stud is arranged at a side of the partition wall which is bounded by an upper line of the bevelled edge.

6. A kitchen machine as claimed in any one of the preceding Claims, characterised in that the tongues have bevelled, rounded ends.

7. A coupling having two coupling parts and suitable for use in a kitchen machine as claimed in Claim 1, 3, 4, 5 or 6.

8. A coupling part suitable for use in a kitchen machine as claimed in Claim 1, 3, 4, 5or6.

9. A kitchen machine substantially as hereinbefore described with reference to the accompanying drawings.

10. A coupling having two coupling parts substantially as hereinbefore described with reference to the accompanying drawings.

11. A coupling part substantially as hereinbefore described with reference to the accompanying drawings.