GB2149497A - Improvements in or relating to cooker hobs - Google Patents

Abstract

A cooker hob (1) fitted with either gas burners (2) or electric rings has a cover (17) pivoted to it and counterbalanced with a spring (31) housed in a pressing (23) in such manner that the closing weight of the cover is fully counterbalanced when the cover is at a position between its fully closed and fully opened positions. Associated with the cover is a valve controlling gas flow to the gas burner (2) or a switch controlling the supply of electricity to the rings, the valve or switch being operated by a cam actuated rod (47) to terminate the supply of gas or the flow of electricity when the cover reaches its fully counterbalanced position. <IMAGE>

Description

SPECIFICATION Improvements in or Relating to Cooker Hobs This invention relates to cooker hobs.

Nowadays, cooker hobs are to be found as separate units for building into a kitchen work surface and are no longer simply part of a freestanding cooker. A modern requirement in kitchen design centres on easy-to-clean surfaces and simple, unclutted aesthetic lines but cooker hobs with gas burners and their associated supports for cooker utensils or with electric rings do not blend readily into the lines of the modern kitchen. It has been proposed to conceal the hob when not in use and this is most easily done by fitting the hob with a cover. Such a cover must be easy to use and must not expose a user to any risk of injury.

Thus, a simple cover that a user merely lifts on and off is clearly not satisfactory whilst a cover hinged to the hob itself presents a considerable hazard to a user if allowed to fall into its closed position. Counterweighting of the cover reduces that hazard but conventional methods of counterweighting do not provide a complete solution.

According to the present invention, a cooker hob has a body portion and a cover hinged to the body portion, the cover being movable between an open position allowing access to the body portion and a closed position in which the cover covers the body portion, the closing weight of the cover being counterbalanced in a manner such that the closing weight of the cover is fully counterbalanced at an intermediate position of the cover between the fully open and fully closed positions and remain fully counterbalanced as the cover moves between the intermediate and the fully closed position.

According to another aspect of the present invention, a cooker hob has a body portion and a cover linked to the body portion, the cover being movable between a fully open position giving access to the body portion and a closed position in which the cover covers the body portion, the body portion accommodating one or more gas burners and/or electric rings, and in which means are provided for controlling the supply of gas to the or each burner or the supply of electricity to the or each ring, said means being operatively connected to the cover in a manner such that the means is actuated to terminate the supply of gas or electricity before the cover reaches its fully closed position.

The supply of gas or electricty may be restored during the movement of the cover from its fully closed to its fully open position.

The supply of gas or electricity may be terminated at the intermediate position.

The closing weight of the cover may be counterbalanced by a spring mounted for pivotal movement about a fixed axis spaced from the hinge axis of the cover.

The cover may be linked to the body portion by a helical spring in such manner that the spring is loaded as the cover moves from its open to its closed position and unloaded on the reverse movement of the cover.

The helical spring may be mounted upon a shaft that is mounted to rotate about the fixed axis.

Means may be provided for varying the preloading of the spring and in one embodiment, the spring is positioned on the shaft between a fixed support and a movable support whose position determines the extent of the preloading.

By way of example only, a gas hob embodying the invention will now be described in greater detail with reference to the accompanying drawings of which: Fig. is a perspective view of the hob, Fig. 2 is a perspective view of a cover bias and gas valve control mechanism forming part of the hob, Fig. 3 shows the cover bias and gas valve control mechanism in more detail, and, Fig. 4 is an explanatory diagram.

The gas hob shown in Fig. 1 comprises an open topped, box-like enclosure 1 housing a gas rail for feeding, via control valves, gaseous fuel to gas burners whose heads 2 are shown in Fig. 1 above a spillage tray 3 which closes part of the open top of the enclosure 1. The gas valves carry control knobs 4 located above a control panel 5 which closes the remaining part of the open top of the enclosure 1 and is separated from the spillage tray 3 by a hollow box-like structure 6 apertured to allow entry of air into the structure 6 and so into the enclosure 1 to provide primary air for the gas fed to the burner heads. Seated upon the spillage tray 3 are pan supports 7.

Also housed within the enclosure 1 is an electrical igniter whose igniter electrodes are associated with the burner heads 2. Operation of the igniter is controlled by a push-button 8.

Secured to the rear wall at each end thereof are brackets 9 of similar construction. One of the brackets 9, the right-hand one as seen in Fig. 1, is associated with a cover bias mechanism and is shown in Fig. 2.

Both brackets have a lower channel-shaped member 10 with holes in the base 11 thereof by which the member is secured by screws to the rear wall of the enclosure 1. The upper part of the bracket comprises spaced limbs 12, 13 supporting a spindle 14 which projects outwardly beyond the limbs 12, 13 as seen in Fig. 2, the projecting ends being indicated by reference numerals 15 and 16.

The hob has a cover 17 which comprises a central panel 18 of heat-resisting glass mounted in a frame comprising side frame members 19, 20 and top and bottom frame members 21,22, top member 21 being cut away at 21 a to enable a user to grasp the cover more easily when closed preparatory to opening it. As can be seen from Fig. the side frame members 19,20 extend beyond the bottom frame member 22, each extension having a circular hole in it.

Positioned alongside side frame member 20 is channel-shaped metal pressing 23 removably secured to the member 20 by screws (not shown) and which is formed with a raised part 24 apertured at 25. The pressing 23 has two projections 26, 27 that are co-extensive with the extension of the frame members 19,20. Adjacent the aperture 25 the pressing has two internal lugs (not shown).

The cover 17 is pivotally supported on the spindles 14. The projection 15 of the spindle of the left-hand (as seen in Fig. 1) bracket engages the hole in the extension of side frame member 19, while the projection 15 of the spindle 14 of the right-hand bracket engages the hole on projection 26 and the projection 16 of the same spindle 14 engages the holes on projection 27 and the hole in the extension of the side frame member 20.

If desired, a bridging member or strip may be used to fill in the gaps at the back of the enclosure 1 between the brackets 9.

The cover bias mechanism comprises a shaft 28 secured at its lower (as seen in Fig. 2) end to a cam member 29 pivotally mounted upon an axle 30 that extends between the limbs 12, 13 of the right-hand (as seen in Fig. 1) bracket 9. Axle 30 is parallel with spindle 14.

Carried by the shaft 28 is a helical spring 31 whose lower (as seen in Fig. 2) end rests upon collar 32 having a central boss 33 seen more clearly in Fig. 3.

The collar 32 rests upon lugs 34 projecting from the surface of the shaft 28. In contact with the upper end of spring 31 is another collar 35 with a boss 36 located within the upper end of the spring. Collar 35 is movable along shaft 28 and its upper surface has an annuiar recess (not shown) in which seats one end of an adjuster tube 37 externally threaded as shown and formed, at its upper end, with a head 38 having a series of spaced, radially extending holes 39. Carried on the adjuster tube 37 is a member 40 with diametral "wings" 41 contoured to form semicircular supports whose function will be described below.

Attached to the rear of the right-hand bracket 9 is a further bracket 42 (Fig. 3) in whose limbs bushes 43 are secured. Slidably mounted in the bushes 43 is a cam follower rod 44 whose upper end (as seen in Fig. 3) is held in contactwith cam member 29 buy a spring 45 located, as shown, between a collar 46 on the rod 44 and one of the arms of the bracket 42. The rod 44 has a portion 47 that extends through a slot in the bracket 9 as shown in Fig. 2 forwardly into the enclosure 1 passed the operating member 48 of a gas control valve 49 that controls gas flow to the gas rail referred to above and is housed in the enclosure 1.

The portion 47 of the cam follower rod is located in guides (not shown) within the enclosure. The shaft 28 carrying the spring 31 and associated components is located in the channel-shaped pressing 23. The pressing is then placed in position with the lugs thereon positioned in the wings 41 on the member 40. The pressing 23 is then secured to the side member 20. As thus arranged, the adjuster head 38 is located immediately adjacent the aperture 25 so permitting the radial holes 39 to be engaged by a tommy bar. Rotation of the head 38 by the tommy bar screws the adjuster tube 37 through the member 40 and thus increases or decreases the degree of compression of the spring 31.

As can be seen from Fig. 2, the axis of operation of the cover 17 as represented by spindles 14 is spaced upwardly and behind the axis of rotation of the shaft 28 as represented by the axle 30. Those axes of rotation are shown in Fig. 4 at 14 and 30.

In Fig. 4, shaft 28 is represented by the line 28 and the cover 17 by line 17. The point of engagement of the wings 41 with the lugs on the pressing 23 is represented by point 41. Collar 32 is indicated by point 32.

As the cover 17 is closed by moving it in the direction of the arrows heads 50 (Fig. 4) spring 31 is compressed, the amount of the compression being given by the expression.

[(a+d)-b]-[a-(b+c)j a, b, c and d being the lengths indicated in Fig. 4.

Spring 31 thus resists closure of the cover 17. The initial state of compression of the spring 31 is such that the closing weight of the cover is fully counterbalanced by the spring 31 when the cover 17 is about halfway down towards the enclosure 1, i.e.

when the inclination of the cover is the horiontal is about 45 . In this position, it is arranged that the cam follower rod has been moved by the cam member 29 to an extent sufficient to close the valve 49.

The pre-loading of the spring 31 determines the exact inclination of the cover 17 at which the closing weight of the cover 17 is just balanced by the spring and this inclination can be greater or smaller than the 45" referred to above provided that the weight is fully balanced before the cover reaches its closed position.

It will be appreciated that, before the intermediate position is reached, the closing weight of the cover 17 is not fully counterbalanced so that should the user release the cover 17 before that position is reached, the spring will return the cover 17 to its fully open vertical position.

Further closing movement of the cover 17 is effected by the user applying an appropriate downward force. During this further closing movement, the closing weight of the cover remains balanced by the spring 31 so that, if the user relaxes the applied downward force, the cover 17 will remain stationary and will not move, either in a closing direction or in an opening direction.

The arrangement described has the advantage that once the user has moved the cover 17 from its stable, fully opened position shown in Fig. 1,the weight of the cover ensures an initial movement of the cover sufficient to result in closure of the valve 49. Thereafter, the closing movement is determined by the user and there is no risk of injury to the hand, or any part thereof, of the user should the hand or the part come into contact with the upper surface of the hob as the cover 17 is closed. The recess 22 in the frame of the cover 17 enables the user to grasp the cover 17 more easily when closed preparatory to opening it.

The purpose of the valve 49 is to ensure that gas flow to the burner heads 2 is always cut off before the cover 17 reaches a fully closed position. Whilst the hob may carry a notice warning the user to shut off the fuel flow, using the appropriate knob 4, to any burner head in operation before closing the cover, no damage will be done to the cover 17 if, inadvertently the user fails to take that action, closure of valve 49 terminating the fuel flow.

When the cover is next opened, the user must ensure that gas flow to any burner previously left operating is terminated by means of the appropriate control knob 4.

Alternatively, it may be preferred to incorporate in valve 49 a mechanism which ensures that the valve, once closed, has to be reset to an open condition by the user before the hob can be brought into use. In this case, an appropriate resetting control is provided on the panel 5.

It will be understood that a spring operating in tension may be used in place of the compression spring 31 described above.

It will be realised from the description set out above that the bias mechanism could be associated with the left-hand bracket 9 and that in this case the control panel 5 will also be located up at the left-hand side of the hob.

Although the use of the valve 49 for shutting off fuel flow to the burners in advance of the cover reaching its fully closed position is preferable, it is not essential provided that the hob carries adequate warnings to the user to shut off any burners in operation before closing the cover.

Furthermore, when the valve 49 is fitted, it may be actuated by some other mechanism than the cam 29 and associated components described above. An actuator for the valve may be quite separate from the bias mechanism of the cover.

Finally, in another embodiment the cover is of light weight construction so that it does not need any counterbalancing. In such an embodiment, a valve similar to valve 49 is provided and is actuated during movement of the cover towards its fully closed position, the valve shutting the fuel flow to the burners before the cover reaches its fully closed position.

It will be appreciated that the hob could be an electric hob with electric rings in place of the burner heads 2 and with electric controls therefor actuated by the knobs 4. In this case, a main control switch replaces the valve 49 described above.

Claims (20)

1. A cooker hob having a body portion and a cover hinged to the body portion, the cover being movable between a fully open position giving access to the body portion and a closed position in which the cover covers the body portion, the closing weight of the cover being counterbalanced in a manner such that the closing weight of the cover is fully counterbalanced at an intermediate position of the cover between the fully open and fully closed positions and remain fully counterbalanced as the cover moves between the intermediate and the fully closed position.

2. A cooker hob having a body portion and a cover linked to the body portion, the cover being movable between a fully open position giving access to the body portion and a closed position in which the cover covers the body portion, the body portion accommodating one or more gas burners and/or electric rings, and in which means are provided for controlling the supply of gas to the or each burner or the supply of electricity to the or each ring, said means being operatively connected to the cover in a manner such that the means is actuated to terminate the supply of gas or electricity before the cover reaches its fully closed position.

3. A cooker hob as claimed in claim 2 in which the supply of gas or electricity is restored during the movement of the cover from its fully closed to its fully open position.

4. A cooker as claimed in claims 1 and 2 in which the supply of gas or electricity is terminated at the intermediate position of the cover.

5. A cooker hob as claimed in claim 1 in which the closing weight of the cover is counterbalanced by a spring mounted for pivotal movement about a fixed axis spaced from the hinge axis of the cover.

6. A cooker hob as claimed in claim 5 in which the cover is linked to the body portion by a helical spring in a manner such that the spring is loaded as the cover moves from its open to its closed position and unloaded on the reverse movement of the cover.

7. A cooker hob as claimed in claim 5 or 6 in which the spring is located within the cover.

8. A cooker hob as claimed in claim 7 in which the cover includes a space in which the spring is accommodated, and a removable cover covering the space.

9. Acooker hob as claimed in claims 1 and 2 and claim 5,6,7 or 8 or as claimed in claim 4 and claim 5, 6,7 or 8 and in which the means comprises a gas valve or electric switch linked to the cover.

10. A cooker hob as claimed in any one of claims 5, 6,7,8 or 9 in which means are provided for varying the pre-loading of the spring.

11. A cooker hob as claimed in any one of claims 5,6,7,8,9 or 10 in which the spring is a compression spring.

12. A cooker hob as claimed in claim 11 in which the spring is a helical spring mounted upon a shaft mounted to rotate about the fixed axis.

13. A cooker hob as claimed in claim 11 or 12 when appended to claim 10 in which the spring is positioned between a fixed abutment on the shaft and movable collar adjustable in position relatively to the shaft to vary the pre-ioading of the spring.

14. A cooker hob as claimed in claim 13 in which the movable collar is adjustable in position by means of an adjuster tube movable along the shaft and carrying a member by means of which the cover is operatively connected to the spring.

15. A cooker hob as claimed in claim 14 in which the adjuster tube is in screw-threaded attachment with the member, and in which the adjuster tube includes a portion aligned with an aperture in the removable cover.

16. A cover hob as claimed in claim 2 in which the means for controlling the supply of gas or electricity is actuated by a cam member movable with the cover.

17. A cooker hob as claimed in any one of claims 11-15 in which the shaft carries a cam surface, and in which the gas valve or electric switch is operable by a cam follower movable by the cam surface.

18. A cooker hob as claimed in claim 17 in which the cam surface is rotatable about the fixed axis of rotation of the spring.

19. A cooker hob as claimed in any one of claims 1, or 4-18 in which the intermediate position is the position of the cover when inclined at an angle of 45" to the horizontal.

20. A cooker hob substantially as herein described with reference to and as illustrated by the accompanying drawings.