WO2015091114A1

WO2015091114A1 - A bottle warmer having a control mechanism for a rotary input

Info

Publication number: WO2015091114A1
Application number: PCT/EP2014/077095
Authority: WO
Inventors: Alexander VAN ROOIJEN
Original assignee: Koninklijke Philips N.V.
Priority date: 2013-12-16
Filing date: 2014-12-10
Publication date: 2015-06-25
Also published as: RU155084U1; CN204394279U; CN104706226A

Abstract

The present application relates to a bottle warmer (1) having a rotatable control knob (11) and a thermostat (3) having a rotary input (4). The bottle warmer includes a control mechanism comprising a flexible coupling (12). The flexible coupling rotatably couples the control knob to the rotary input such that the rotational axis (X-X) of the control knob may be arranged non-parallel with the rotational axis (Y-Y) of the rotary input.

Description

A BOTTLE WARMER HAVING A CONTROL MECHANISM FOR A ROTARY INPUT

FIELD OF THE INVENTION

The present invention relates to a bottle warmer comprising a thermostat having a rotary input, and a control mechanism for rotary input of the thermostat. BACKGROUND OF THE INVENTION

Bottle warmers are commonly used to warm bottles of milk for consumption by infants. Known bottle warmers comprise a heating element that is controlled by a thermostat. The thermostat comprises a control knob that is coupled to the rotary input of the thermostat by a rigid shaft so that the temperature of the bottle warmer can be adjusted to the desired temperature by rotating the control knob. It is important that the temperature of the bottle warmer can be accurately controlled so that the milk is heated to and kept at a temperature that is safe for consumption by infants.

SUMMARY OF THE INVENTION

It has been found that factors such as manufacturing tolerances, thermal expansion or misalignment of components of bottle warmers known in the art can result in the rotational axis of the rotary input and the rotational axis of the control knob not being coaxially aligned when such bottle warmers are assembled. This can cause a radial force to be exerted on the rigid shaft that results in a force being exerted on the rotary input of the thermostat that can change the temperature setting of the thermostat. Therefore, the milk may not be heated to the temperature selected by a user and instead may be heated to a temperature that is not safe for consumption by infants. Furthermore, non-coaxial alignment of the rotational axes of the rotary input and control knob can result in the control knob being positioned such that there is a gap between the control knob and the housing of the bottle warmer. This gap may unhygienically collect dirt and debris.

It is an object of the invention to provide a bottle warmer having a control mechanism which substantially alleviates or overcomes the problems mentioned above.

According to the present invention, there is provided a bottle warmer comprising a rotatable control knob, a thermostat having a rotary input, and a control mechanism comprising a flexible coupling that rotatably couples the control knob to the rotary input such that the rotational axis of the control knob may be arranged non-parallel with the rotational axis of the rotary input. Therefore, the control knob can be easily and reliably coupled to the rotary input even if factors such as manufacturing tolerances, thermal expansion or misalignment of components of the control mechanism result in the axes of the rotary input and the control knob not being coaxially aligned.

In one embodiment, the flexible coupling comprises a first mount that is coupled to the control knob, a second mount that is coupled to the rotary input, and a connection member that pivotally couples the first and second mounts. The pivotal movement of the connection member relative to the first and second mounts allows for the control knob and rotary input to be non-coaxially aligned. In addition, the control knob, connection member, and first and second mounts can be coupled together to form the control mechanism prior to the control mechanism being coupled to the rotary input, thereby improving ease of manufacturing. In one embodiment, the connection member is pivotally coupled to the first mount about a first pivot axis and a second pivot axis that is perpendicular to the first pivot axis, and is pivotally coupled to the second mount about a third pivot axis and fourth pivot axis that is perpendicular to the third pivot axis. The first mount may be integrally formed with the control knob so that assembly of the control mechanism is simplified.

In one embodiment, the first mount comprises a first recess and the second mount comprises a second recess and the connection member comprises distal ends which are configured to be received within the first and second recesses respectively. Therefore, the distal ends of the connection member are constrained from moving in the radial direction of the rotary input and control knob by the portion of the first and second mounts at the periphery of each recess.

In one embodiment, one of the first mount and a first end of the connection member comprises at least one slot and the other one of the first mount and the first end of the connection member comprises a pair of protrusions that are configured to be slidably received in the or each slot. In one embodiment, one of the second mount and a second end of the connection member comprises at least one slot and the other of the second mount and the second end of the connection member comprises a pair of protrusions that are configured to be slidably received in the or each slot. The slidable engagement of the protrusions in the or each slot allows for the control knob to be slid relative to the rotary input in the axial direction thereof so that the distance therebetween can be adjusted. In one embodiment, the flexible coupling comprises a double cardan coupling. It has been found that a double cardan coupling allows for a relatively large radial offset between the rotational axes of the control knob and rotary input, is relatively inexpensive to produce, and can be manufactured using injection moulding and so is relatively easy to produce in large volumes. Furthermore, a double cardan coupling can provide a high torsional stiffness so that a given rotation of the control knob will result in a similarly sized and predictable rotation of the rotary input.

The control mechanism allows for the control knob to be coupled to the rotary input of the thermostat in such a manner that the rotational axes of the rotary input and control knob are not coaxially aligned and are non-parallel, without a radial force being exerted on the rotary input that can cause the temperature setting of the thermostat to be altered. Therefore, an offset error in the relationship between the rotational position of the control knob and the temperature setting of the bottle warmer is avoided.

In one embodiment, the flexible coupling comprises a thermal insulation material to thermally insulate the control knob from the rotary input of the thermostat.

Therefore, when the bottle warmer is heated, the thermal insulating material of the flexible coupling will restrict the heat generated from being transferred to the control knob. Therefore, the risk of a user being burned when they touch the control knob is reduced.

In one embodiment, the bottle warmer comprises a housing and the control knob is configured to sit flush to the housing. The housing may comprise a circular wall portion and the control knob may comprise a surface that is configured to sit flush to the circular wall portion. Therefore, the control knob is prevented from moving in the radial direction relative to the housing. This prevents a gap from forming between the control knob and the housing of the bottle warmer, which could otherwise unhygienically collect dirt and debris. Furthermore, the restriction of the control knob in the radial direction relative to the housing prevents damage to the rotary input of the thermostat if a user inadvertently applies a radial force to the control knob.

These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of a known bottle warmer; Figure 2 is a cut-away perspective view of the bottle warmer of Figure 1; Figure 3 is a cross-sectional top view of the bottle warmer of Figure 1;

Figure 4 is a perspective view of a bottle warmer comprising the control mechanism according to an embodiment of the invention;

Figure 5 is a cut-away perspective view of the bottle warmer of Figure 4; Figure 6 is an alternative cut-away perspective view of the bottle warmer of

Figure 4;

Figure 7 is an exploded perspective view of the control mechanism of the bottle warmer of Figure 4;

Figure 8 is an assembled perspective view of the control mechanism of the bottle warmer of Figure 4;

Figure 9 is a cross-sectional side view of the bottle warmer of Figure 4; and,

Figure 10 is a cross-sectional top view of the bottle warmer of Figure 4.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Referring now to Figures 1 to 3, a known bottle warmer 1 is shown. The bottle warmer comprises a housing 2 and a thermostat 3. The thermostat 3 is mounted inside the housing 2 and comprises a rotary input 4 that is rotatable to adjust the temperature of the bottle warmer 1.

The housing 2 of the bottle warmer 1 comprises a first housing portion 5 and a second housing portion 6. A first semi-circular wall portion 5 A extends from the exterior surface of the first housing portion 5 and a second semi-circular wall portion 6A extends from the exterior surface of the second housing portion 6. The first housing portion 5 and the second housing portion 6 are joined together to form the housing 2 such that the first semicircular wall portion 5 A and the second semi-circular wall portion 6A meet to form a circular wall portion 2 A.

The first housing portion 5 comprises an internal wall 7 that has a semicircular shaped recess 7A. The second housing portion 6 comprises an internal wall (not shown) that has a semi-circular shaped recess (not shown) that aligns with the semi-circular shaped recess 7A of the internal wall 7 of the first housing portion 5 to form a circular aperture (not shown) when the first housing portion 5 and the second housing portion 6 are joined together. The thermostat 3 comprises a control mechanism 1 A that has a control knob 8 that is integrally formed with a tubular member 8A and coaxially aligned therewith. The tubular member 8 A is coupled to the rotary input 4 of the thermostat 3 by a rigid shaft 9. The tubular member 8A comprises a section of reduced diameter 8B having a flanged portion 8C extending radially therefrom. To mount the control knob 8 to the bottle warmer 1, the section of reduced diameter 8B of the tubular member 8A is received within the semi-circular recess 7A in the internal wall 7 of the first housing portion 5. The first housing portion 5 and the second housing portion 6 are then joined together to form the housing 2 so that the section of reduced diameter 8B is disposed in the circular aperture formed between the internal walls 7 of the first housing portion 5 and the second housing portion 6, and the flanged portion 8C of the tubular member 8A is disposed against the inside surfaces of the internal walls 7. Therefore, if the control knob 8 is urged axially away from the housing 2 then the flanged portion 8C is urged against the internal walls 7, thereby preventing the control knob 8 from being separated from the housing 2.

The thermostat 3 is mounted to the inside of the first housing portion 5 on a bracket (not shown) prior to the first housing portion 5 and the second housing portion 6 being joined together. The thermostat 3 comprises a base 3 A with a holding plate 3B and a control plate 3C extending therefrom. A screw actuator 4A is rotatably mounted to the holding plate 3B and is urged against the control plate 3C to exert a bending force thereon. The amount of bending force exerted on the control plate 3C controls the temperature of the bottle warmer 1. The screw actuator 4A is coupled to the rotary input 4 so that when the rotary input 4 is rotated the screw actuator 4A also rotates and thus moves axially towards or away from the control plate 3C, depending on the direction of rotation of the rotary input 4, thereby altering the bending force exerted on the control plate 3C and thus the temperature of the bottle warmer 1. Therefore, the temperature of the bottle warmer 1 can be adjusted by rotation of the control knob 8, which is rotatably coupled to the rotary input 4 by the rigid shaft 9, with each angular position of the control knob 8 relative to the housing 2 representing a different temperature of the bottle warmer 1. The relationship between the rotational position of the control knob 8 relative to the housing 2 and the temperature of the bottle warmer 1 is graphically indicated to the user by the alignment of a notch (not shown) on the control knob 8 with a visual indicator 2B provided on the housing 2 about the circular wall portion 2A.

When the bottle warmer 1 is assembled, it is desirable that the rotational axis of the rotary input 4 is aligned coaxially with the central axis of the circular aperture in the housing 2. However, factors such as manufacturing tolerances, thermal expansion of the different components of the bottle warmer 1 or misalignment of the bracket (not shown) that mounts the thermostat 3 in the housing 2 can result in the axes of the rotary input 4 and circular aperture not being coaxially aligned.

If the rotational axis of the rotary input 4 and the central axis of the circular aperture are not coaxial, then when the control knob 8 is mounted to the rotary input 4 by the rigid shaft 9 the section of reduced diameter 8B may be urged against a portion of the edge of the circular aperture in the housing 2. This can cause the housing 2 to exert a force on the section of reduced diameter 8B, and therefore the rigid shaft 9, in the radial direction thereof, resulting in a bending force being exerted on the holding plate 3B that urges the holding plate 3B, and thus the screw actuator 4A, against the control plate 3C. This is undesirable since the resultant bending of the control plate 3C would cause the temperature setting of the thermostat 3 to be altered such that an offset error is introduced into the relationship between the angular position of the control knob 8 and the temperature of the bottle warmer 1.

Therefore, if a user were to rotate the control knob 8 to align the notch (not shown) of the control knob 8 with the visual indicator 2B on the housing 2 to select a temperature level of the bottle warmer 1 , the resultant temperature of the bottle warmer 1 would be different to that indicated by the visual indicator 2B. This can be dangerous as the bottle warmer 1 may heat the milk contained in a bottle being warmed to a temperature that is not safe for consumption by an infant. In addition, the rigid shaft 9 being urged against the edge of the circular aperture in the housing 2 can result in increased friction between the control knob 8 and housing 2, which may result in excessive force being required to rotate the control knob 8.

To avoid a radial force being exerted on the rigid shaft 9 and therefore a temperature offset error being introduced in the event that the rotational axis of the rotary input 4 and the central axis of the circular aperture in the housing 2 are not coaxially aligned, one solution is to increase the diameter of the circular aperture. In such a configuration, even if there is a large displacement between the rotational axis of the rotary input 4 and the central axis of the circular aperture, the section of reduced diameter 8B of the tubular member 8 A will not be urged against the edge of the circular aperture in the housing 2.

Therefore, the housing 2 will not exert a radial force on the rigid shaft 9 and thus the holding plate 3B of the thermostat 3 will not be bent and so a temperature offset error will not be introduced. However, such a configuration would result in the control knob 8 being free to move in the radial direction of the rigid shaft 9 and therefore the control knob 8 may wobble when rotated by a user. In addition, a gap G may form between the control knob 8 and the housing 2, which is unsightly and may unhygienically collect dirt and debris. Furthermore, the gap G between the control knob 8 and housing 2 may result in the notch of the control knob 8 not being correctly aligned with the visual indicator 2B provided on the housing 2, which can result in an incorrect temperature of the bottle warmer 1 being indicated to the user.

Referring now to Figures 4 to 9, a bottle warmer 10 according to an embodiment of the invention is shown. The bottle warmer 10 comprises a housing 2 and thermostat 3 that have some features similar to those described in relation to the known bottle warmer 1 described above, which like features retaining the same reference numerals. The thermostat 3 is mounted inside the housing 2 and comprises a rotary input 4 that is rotatable to adjust the temperature of the bottle warmer 10.

The thermostat 3 comprises a control mechanism 10A that has a control knob 11 that is coupled to the rotary input 4 of the thermostat 3 by a flexible coupling 12. The flexible coupling 12 comprises a double cardan coupling that includes a first mount 13, a second mount 14 and a connection member 15. The first mount 13 is integrally formed with the control knob 11 and is aligned coaxially with the rotational axis X-X of the control knob 11. The second mount 14 is mounted to the rotary input 4 by adhesive and is aligned coaxially with the rotational axis Y-Y of the rotary input 4. The first mount 13 comprises a tubular wall 13A with a recess 13B formed therein. Similarly, the second mount 14

comprises a tubular wall 14A with a recess 14B formed therein. A first pair of slots 13C is formed in diametrically opposed portions of the tubular wall 13A of the first mount 13 at the end thereof that is distal to the control knob 11. A second pair of slots 14C is formed in diametrically opposed portions of the tubular wall 14A of the second mount 14 at the end thereof that is distal to the rotary input 4.

The connection member 15 comprises an elongate member 15A with a first pair of protrusions 15B and a second pairs of protrusions 15C. The first pair of protrusions 15B extend from opposite sides of the elongate member 15A and are disposed at a first end thereof. The second pair of protrusions 15C extend from opposite sides of the elongate member 15A at a second end thereof, distal to the first end.

As with the known bottle warmer 1 described above, the housing 2 of the bottle warmer 10 of the presently described embodiment of the invention comprises a first housing portion 5 and a second housing portion 6. In addition, the housing 2 comprises a first semi-circular wall potion 5A and a second semi-circular wall portion 6A that meet to form a circular wall portion 2A when the first housing portion 5 and the second housing portion 6 are joined to from the housing 2. The first housing portion 5 comprises an internal wall 7 that has a semi-circular shaped recess 7A. The second housing portion 6 comprises an internal wall (not shown) that has a semi-circular shaped recess (not shown) that aligns with the semicircular shaped recess 7A of the internal wall 7 of the first housing portion 5 to form a circular aperture (not shown) when the first housing portion 5 and the second housing portion 6 are joined together.

The control knob 11 comprises an internal lip 11 A that is configured to be received against the inside surface of the circular wall portion 2A when the control knob 11 is mounted to the bottle warmer 10. The interface between the internal lip 11A and the circular wall portion 2A allows for rotation of the control knob 11 relative to the housing 2 about the rotational axis X-X of the control knob 11 whilst restraining the control knob 11 from moving relative to the housing 2 in the radial direction of the control knob 11.

The first mount 13 of the flexible coupling 12 comprises a section of reduced diameter 16 having a flanged portion 16A extending radially therefrom. When the control knob 11 is mounted to the bottle warmer 10 the section of reduced diameter 16 of the first mount 13 is received within the circular aperture formed in the housing 2 so that the control knob 11 is supported by the housing 2 in the radial direction of the control knob 11. The curved outer surface of the section of reduced diameter 16 sits flush against the curved surfaces of the internal walls 7 at the periphery of the circular aperture to prevent radial movement of the control knob 11 relative to the housing 2. In addition, when the control knob 11 is mounted to the housing 2 the flanged portion 16A of the first mount 13 is disposed against the inside surface of each of the internal walls 7. Therefore, if the control knob 11 is urged axially away from the housing then the flanged portion 16A is urged against the internal walls 7 and so the control knob 11 is prevented from being separated from the housing 2.

The constraint of the control knob 11 in the radial and axial directions relative to the housing 2 prevents a gap from forming between the control knob 11 and housing 2. The prevention of a gap between the control knob 11 and housing 2 is desirable since it prevents dirt and debris collecting therebetween which can be unhygienic. In addition, the support of the control knob 11 in the axial and radial directions thereof prevents damage to the rotary input 4 of the thermostat 3 if a user inadvertently applies a radial or axial force to the control knob 11.

When the bottle warmer 10 is assembled, the thermostat 3 is mounted to the inside of the first housing portion 5 on a bracket (not shown). The first end of the elongate member 15A is then disposed in the recess 13B in the first mount 13, which is coupled to the thermostat 3, such that the first pair of protrusions 15B are slidably received in the first pair of slots 13C. The control knob 11 is then mounted to the housing 2 in the manner described above such that the internal lip 11 A of the control knob 11 sits flush against the inside surface of the circular wall portion 2A. When the control knob 11 is mounted to the housing 2, the second end of the elongate member 15A is disposed in the recess 14B of the second mount 14, which is coupled to the control knob 11, such that the second pair of protrusions 15C are slidably received in the second pair of slots 14C.

Since the first pair of protrusions 15B are received with the first pairs of slots 13C, rotation of the first mount 13 will cause the tubular wall 13A thereof to exert a force on the first pair of protrusions 15B so that the connecting member 15 rotates. This will result in the second pair of protrusions 15C exerting a force on the tubular wall 14A of the second mount 14 so that the second mount 14 rotates. Therefore, the flexible coupling 12 rotatably couples the control knob 11 to the rotary input 4 of the thermostat 3 and so the temperature of the bottle warmer 10 can be adjusted by rotation of the control knob 11, with each angular position of the control knob 11 representing a different temperature of the bottle warmer 10. The relationship between the rotational position of the control knob 11 relative to the housing 2 and the temperature of the bottle warmer 10 is graphically indicated to the user by the alignment of a notch 1 IB on the control knob 11 with a visual indicator 2B provided on the housing 2 about the circular wall portion 2A.

The first pair of protrusions 15B of the connection member 15 are rotatable about their central axis in the first pair of slots 13C so that the connection member 15 is pivotal relative to the first mount 13 about a first pivot axis Zl-Zl . In addition, the first pair of protrusions 15B are slidable within the first pair of slots 13C so that the connection member 15 is pivotal relative to the first mount 13 about a second pivot axis Z2-Z2 that is perpendicular to the first pivot axis Zl-Zl . Similarly, the second pair of protrusions 15C of the connection member 15 are rotatable about their central axis in the second pair of slots 14C so that the connection member 15 is pivotal relative to the second mount 14 about a third pivot axis Z3-Z3. In addition, the second pair of protrusions 15C are slidable within the second pair of slots 14C so that the connection member 15 is pivotal relative to the second mount 14 about a fourth pivot axis Z4-Z4 that is perpendicular to the third pivot axis Z3-Z3.

The first pivot axis Zl-Zl and second pivot axis Z2-Z2 allow for the connection member 15 to be rotatably coupled to the first mount 13, and thus the control knob 11, without requiring parallel or coaxial alignment of the rotational axis of the connection member 15 with the rotational axis X-X of the control knob 11. Similarly, the third pivot axis Z3-Z3 and fourth pivot axis Z4-Z4 allow for the connection member 15 to be rotatably coupled to the second mount 14, and thus the rotary input 4, without requiring parallel or coaxial alignment of the rotational axis of the connection member 15 with the rotational axis Y-Y of the rotary input 4. Therefore, the flexible coupling 12 between the control knob 1 1 and rotary input 4 allows for the control knob 11 to be coupled to the rotary input 4 without the rotational axis X-X of the control knob 11 having to be coaxially aligned with the rotational axis Y-Y of the rotary input 4.

When the thermostat 3 is mounted to the first housing portion 5 during assembly of the bottle warmer 10, the rotational axis Y-Y of the rotary input 4 may be positioned such that it is not coaxial with the central axis of the circular aperture in the housing 2. This misalignment can be due to, for example, manufacturing tolerances, thermal expansion of the different components of the bottle warmer 10, or misalignment of the bracket (not shown) that holds the thermostat 3 in position in the housing 2. However, unlike the rigid shaft 9 of the known bottle warmer 1 described above, the flexible coupling 12 of the bottle warmer 10 of the presently described embodiment of the invention allows for the control knob 11 to be mounted to the rotary input 4 such that the rotational axis X-X of the control knob 11 and the rotational axis Y-Y of the rotary input 4 are offset from each other by a radial offset R. This means that the control knob 11 can be mounted to the housing 2 in such a way that the section of reduced diameter 16 sits flush to the curved surfaces of the internal walls 7 at the periphery of the circular aperture, to prevent radial movement of the control knob 11, without the housing 2 exerting a radial force on the section of reduced diameter 16. Therefore, the holding plate 3B is not bent towards the control plate 3C of the thermostat 3 and so the thermostat 3 being mounted to the housing 2 in such a manner that the rotational axis Y-Y of the rotary input 4 is not coaxial with the central axis of the circular aperture does not result in an offset error in the relationship between the rotational position of the control knob 11 and the temperature of the bottle warmer 10. In addition, the control knob 11 can be mounted to the housing 2 such that the internal lip 11 A sits flush to the inside surface of the circular wall portion 2A and no gap is formed between the control knob 11 and the housing 2, thereby preventing dirt and debris collecting between the housing 2 and control knob 11.

It should be recognised that a 'flexible coupling' refers to any coupling capable of rotatably coupling the control knob 11 to the rotary input 4 without requiring that the rotational axis X-X of the control knob 11 and the rotational axis Y-Y of the rotary input 4 are parallel and/or aligned coaxially. Although in the above described embodiments the flexible coupling 12 comprises a double cardan coupling, in alternate embodiments (not shown) the flexible coupling 12 may comprise other types of coupling that allow for non- parallel rotatable coupling of the control knob 11 and rotary input 4. Examples of such flexible couplings include a cardan coupling, schmidt coupling, universal joint, oldham coupling, rzeppa joint or thompson coupling. These coupling have been found to have a high torsional stiffness and therefore minimise error in the relationship between the rotational position of the control knob 11 and the temperature of the bottle warmer 10.

In one embodiment, the flexible coupling 12 comprises a thermal insulation material, for example, polystyrene, fibreglass or cellulose, so that heat transfer from the housing 2 of the bottle warmer 10 to the control knob 11 is reduced.

Although in the above described embodiment the first pair of protrusions 15B and the second pair of protrusions 15C are provided on the elongate member 15A and the first pair of slots 13C and the second pair of slots 14C are provided on the first mount 13 and the second mount 14 respectively, in an alternate embodiment (not shown) the first and second pairs of protrusions are provided on the first and second mounts respectively and the first and second pairs of slots are provided on the elongate member.

In the above described embodiments the flexible coupling 12 comprises a double cardan coupling having the first pair of protrusions 15B and the second pair of protrusions 15C that are received respectively in the first pair of slots 13C and the second pair of slots 14C to enable the elongate member 15A to be pivotally coupled to the first mount 13 about the first pivot axis Zl-Zl and the second pivot axis Z2-Z2, and pivotally coupled to the second mount 14 about the third pivot axis Z3-Z3 and the fourth pivot axis Z4- Z4. The slidable engagement of the first pair of protrusions 15B and the second pair of protrusions 15C in the first pair of slots 13C and the second pair of slots 14C respectively allows for the distance between the first mount 13 and the second mount 14 to be adjusted in the axial direction of the rotary input 4. Therefore, the control knob 11 can be moved towards the housing 2 so that there is no gap therebetween, regardless of the amount of radial offset R between the rotational axis X-X of the control knob 11 and the rotational axis Y-Y of the rotary input 4. In addition, the above-described configuration of flexible coupling 12 is inexpensive, can be manufactured using injection moulding and so it is relatively easy to produce in large volumes, and allows for a relatively large radial offset R. Furthermore, the flexible coupling 12 described above has a high torsional stiffness and therefore a given rotation of the control knob 11 will result in a similarly sized and predictable rotation of the rotary input 4 and so the flexible coupling 12 reduces error in the relationship between the rotational position of the control knob 11 and the temperature of the bottle warmer 10.

The pivotal movement of the connection member 15 relative to the first mount 13 about the first pivot axis Zl-Zl and second pivot axis Z2-Z2 and relative to the second mount 14 about the third pivot axis Z3-Z3 and fourth pivot axis Z4-Z4 may be achieved using an alternative arrangement of double cardan coupling to that described above. In one such embodiment (not shown), the first mount is pivotally coupled to a first intermediate member about a first pivot axis that is perpendicular to the rotational axis of the control knob. The first end of the connection member is pivotally coupled to the first intermediate member about a second pivot axis that is perpendicular to the first pivot axis and the rotational axis of the control knob. The second end of the connection member is pivotally coupled to a second intermediate member about a third pivot axis that is perpendicular to the rotational axis of the rotary input. The second mount is pivotally coupled to the second intermediate member about a fourth pivot axis that is perpendicular to the third pivot axis and the rotational axis of the rotary input.

In other embodiments (not shown), the flexible coupling comprises a spring or portion of resilient material that couples the first and second mounts and can flex to allow for non-coaxial, non-parallel alignment of the rotational axes of the control knob and rotary input. Such flexible couplings may be inexpensive to manufacture, although they have a lower torsional stiffness and so can result in an error between the rotational position of the control knob and the temperature of the bottle warmer.

Although in the above described embodiments the first mount 13 is integrally formed with the control knob 11, in alternate embodiments (not shown) the first mount 13 is mounted to the control knob 11 with adhesive or a snap-fit or interference fit. Although in the above described embodiment the second mount 14 is mounted to the rotary input 4 using adhesive, in alternate embodiments (not shown) the second mount 14 is mounted to the rotary input 4 with a snap-fit or interference fit or is integrally formed therewith.

It will be appreciated that the term "comprising" does not exclude other elements or steps and that the indefinite article "a" or "an" does not exclude a plurality. A single processor may fulfil the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to an advantage. Any reference signs in the claims should not be construed as limiting the scope of the claims. Although claims have been formulated in this application to particular combinations of features, it should be understood that the scope of the disclosure of the present invention also includes any novel features or any novel combinations of features disclosed herein either explicitly or implicitly or any generalisation thereof, whether or not it relates to the same invention as presently claimed in any claim and whether or not it mitigates any or all of the same technical problems as does the parent invention. The applicants hereby give notice that new claims may be formulated to such features and/or combinations of features during the prosecution of the present application or of any further application derived therefrom.

Claims

CLAIMS:

1. A bottle warmer (1) comprising a rotatable control knob (11), a thermostat (3) having a rotary input (4), and a control mechanism comprising a flexible coupling (12) that rotatably couples the control knob to the rotary input such that the rotational axis (X-X) of the control knob may be arranged non-parallel with the rotational axis (Y-Y) of the rotary input.

2. A bottle warmer (1) according to claim 1, wherein the flexible coupling (12) comprises a first mount (13) that is coupled to the control knob (11), a second mount (14) that is coupled to the rotary input (4), and a connection member (15) that pivotally couples the first and second mounts.

3. A bottle warmer (1) according to claim 2, wherein the connection member (15) is pivotally coupled to the first mount (13) about a first pivot axis (Zl-Zl) and a second pivot axis (Z2-Z2) that is perpendicular to the first pivot axis, and is pivotally coupled to the second mount (14) about a third pivot axis (Z3-Z3) and a fourth pivot axis (Z4-Z4) that is perpendicular to the third pivot axis.

4. A bottle warmer (1) according to claim 3, wherein the first mount (13) comprises a first recess (13B) and the second mount (14) comprises a second recess (14B) and wherein the connection member (15) comprises distal ends which are configured to be received within the first and second recesses respectively.

5. A bottle warmer (1) according to claim 3 or claim 4, wherein one of the first mount (13) and a first end of the connection member (15) comprises at least one slot (13C) and the other one of the first mount and the first end of the connection member comprises a pair of protrusions (15B) that are configured to be slidably received in the or each slot.

6. A bottle warmer (1) according to any one of claims 3 to 5, wherein one of the second mount (14) and a second end of the connection member (15) comprises at least one slot (14C) and the other of the second mount and the second end of the connection member comprises a pair of protrusions (15C) that are configured to be slidably received in the or each slot.

7. A bottle warmer (1) according to any one of claims 2 to 6, wherein the first mount (13) is integrally formed with the control knob (11).

8. A bottle warmer (1) according to any one of the preceding claims, wherein the flexible coupling (12) comprises a double cardan coupling.

9. A bottle warmer (1) according to any preceding claim, wherein the flexible coupling (12) comprises a thermal insulation material.

10. A bottle warmer according to any preceding claim, comprising a housing (2), wherein the control knob (11) is configured to sit flush to the housing.

11. A bottle warmer according to claim 10, wherein the housing (12) comprises a circular wall portion (2 A) and the control knob (11) comprises a surface (HA) that is configured to sit flush to the circular wall portion.