GB2368514A

GB2368514A - Electrically-powered nutcracker

Info

Publication number: GB2368514A
Application number: GB0027237A
Authority: GB
Inventors: Peter Holloway
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-11-02
Filing date: 2000-11-02
Publication date: 2002-05-08
Anticipated expiration: 2020-11-02
Also published as: GB0027237D0; GB2368514B

Abstract

An electrically-powered device for cracking the shells of edible nuts in a domestic situation may be driven by mains power or by batteries such as rechargeable batteries 18. A dc motor 13 may drive a screw thread 3 that in turn moves a piston 2 to compress a nut 1 between the piston and a fixed plate. Movement of a safety cover 20 over the nut and compressing parts may activate a safety cut-out switch which will only then allow compression. A torque-limiting device and means to automatically cease compression on detection of breakage of a nut may be incorporated. Parts of the nutcracker may disassemble for cleaning.

Description

NUT CRACKER THIS INVENTION RELATES TO AN ELECTRICALLY POWERED NUT CRACKING TOOL Many devices already exist for cracking edible nuts in a domestic situation. Popular at Christmas time, the nuts in question are the hard-shelled type, such as Walnuts, Brazil nuts, Cob or Hazelnuts, Pecans and Almonds plus others. The fundamental method, employed over the centuries to crack nuts, is to increase the force applied to the shell, typically from a person's handgrip with the use of lever mechanisms; notwithstanding a few hammer-striking designs.

The drawback with this approach is, that in order to multiply the pressure on the nut, the handles on the cracker have to travel through a larger movement than the jaws of the cracker, thus in some cases the nut will not be squashed sufficiently to crack, or the handles may still be too hard to compress. This especially is the difficulty experienced by the elderly, or persons with weaker grip. Some crackers have a ratcheting mechanism, but these require several compressions to achieve their goal.

This labour saving design endeavours to overcome the problems already mentioned.

According to the present invention there is a small, handheld or tabletop device consisting of a pair of plates, between which the nut to be cracked is placed, a switch is operated by the user, and the plates are brought together by electrical power. The nut is compressed until its case cracks. The jaws are then retracted and the nut is then removed from the cracker, the broken shell removed and the contents eaten.

A specific embodiment of the invention will now be further described by way of an example with reference to the accompanying drawings in which: Referring to the accompanying drawings ; Figure 1 shows two views, an end on and a plan view, showing the key components in cross section. Figure 2, shows a side on view, again in cross section. Figure 3, shows an overview of the example model without the safety cover, showing an example nut in position. External product styling is of course not shown in the patent.

User Operation: With the piston No. 2 retracted, the cover No. 20 is removed and the nut to be cracked is placed in the void between the end of the device No. 19 and the piston No. 2.

The safety cover No. 20 is placed over the nut and exposed moving parts. The action of fitting the cover over the nut and the compressing plates activates a safety cut out switch, which only then will only allow the crushing operation. The user then operates the three position electrical switch No. 17 in the direction to compress the nut. The nut cracks, and the jaws are opened to release the nut. The user removes the safety cover and the nut can be removed to be eaten.

Device operation: The nutcracker consists of a sliding plate or piston No. 2 which is pushed towards the end of the device containing the nut No. 19. The piston No. 2 is propelled by the threaded spindle No. 3. The bore within the piston No. 2 is threaded and when the spindle is rotated in the correct direction, moving the piston No. 2 towards the nut, it provides a force against the thrust plate No. 9. To provide a stop against the thrust plate No. 9, the spindle is fitted with 2 circlips Nos. 24. The circlip is in turn pressed up against a washer No. 7 and a thrust bearing No. 8 is used to reduce the friction against the thrust plate no. 9. In order to retract the piston No. 2, the spindle is rotated in the opposite direction and the second circlip No. 24 retains the spindle against the thrust plate no. 9. The piston No 2 is prevented from rotating itself by two slots, lengthways, on the outside of its body starting from behind the crushing face to the end, these are located by two pinions No. 22.

The body has a seal No. 25 that the piston slides in ; this prevents the ingress of nut parts into the mechanism, for hygiene reasons. The spindle No. 3 is threaded with a suitable pitch thread to achieve the optimum speed and to avoid stripping of the thread under pressure.

The spindle No. 3 is rotated by the gearbox No. 10, which is in turn reducing the rotation rate from its drive input. The input drive to the gearbox No. 10 is provided by the electric motor No. 13.

In this example a D. C. Motor is employed to enable battery operation whilst it is acknowledged that various types of motors could be used. A battery, No. 18, provides the emotive force for the motor. In this example the battery is of the rechargeable type and is recharged when exhausted by the use of a mains transformer. Standard replaceable batteries could be used as an alternative.

In this specific example the gearbox output is directed through a torque-limiting device which is designed to slip if the torque on the spindle No. 3 becomes too great. This spring device can be pre-loaded to set the pressure at which the slippage will occur. The purpose is to prevent damage to the cracker if the jaws encounter an immovable (uncrushable) object.

Also the torque-limiter can operate when the piston No. 2 is fully retracted and the switch No. 17 held on in the retracting direction, allowing the motor to turn without damage.

Claims

1. According to the present invention there is a small, handheld or tabletop device consisting of a pair of plates, between which the nut to be cracked is placed, a switch is operated by the user, and the plates are brought together by electrical power. The nut is compressed until its case cracks. The jaws are then retracted and the nut is then removed from the cracker, the broken shell removed and the contents eaten.

2. The invention as described in claim 1, has the ability to be powered by a battery.

This battery can be of one of two types, either utilizing one or more of the standard disposable variety widely available or using a battery or batteries of a rechargeable nature.

3. The device as described in claims 1 and 2 can be fitted with a safety device in order to prevent harm coming to any persons either operating the device or situated in the near vicinity. This will be by:-a) an interlock mechanism, either electrical or mechanical to prevent the crushing of stray fingers in the moving part of the device, and b) a safety cover that protects individuals from shards of broken nut shell projected from the cracking nut.

4. The device described in claims 1 through 3 above can additionally have the safety lockout mechanism configured to allow the withdrawal of the crushing plates in a safe manner with the safety cover removed, thus facilitating the rapid emptying and redeployment of the device.

5. The device described in claims 1 through 4 above, if fitted with a rechargeable battery or batteries will be recharged by an external mains transformer/dc supply unit, connected either by direct connection or inductive loop. The latter would benefit the cleaning of the device by having a sealed charging point. An indicator can be provided to determine the state of the battery charge/charging.

6. The device described in claims 1 through 5 can be made to disassemble in part, to facilitate cleaning. For safety, the internal moving parts would be made less easy to dismantle.

7. The device as described in claims 1 through 6, can be fitted with a torque-limiting device. This can be fitted to the motor or gearbox, and will allow slippage of the motor drive if a preset torque is exceeded. This will avoid damage to the motor and moving parts if the piston/plates should come up against an immovable object.

8. The nutcracker tool as claimed in claim 1 which automatically detects the cracking of the nut and subsequently stop and reverse the piston drive, the detection being achieved either by the sound given off from the initial crack, or by using a strain gauge or similar device, to detect the sudden drop in resistance to crushing.

8. The device described in claims 1 through 6 can be made to automatically detect, and subsequently stop or reverse the pressure on the nut, upon the cracking of the nut.

This could be achieved by the sound given off from the initial crack, or by using a strain gauge or similar, to detect the sudden drop in resistance to crushing.

9. The device described in claims 1,3, 4,6, 7 and 8 can alternatively be powered from a "mains"supply directly. Amendments to the claims have been filed as follows CLAIMS 1. A small, handheld or tabletop motorised electrically powered semiautomatic nutcracker tool consisting of a body with a nut cavity which includes a moveable piston, that can be driven either in or out of the said cavity by means of a torque limited screw mechanism turned via a gearbox whose input shaft is driven from a switch activated semiautomatically controlled electric motor, to effect breaking of the nut shell within the cavity, and a safety device including a safety cover for the nut cavity.

2. The nutcracker tool as claimed in claim 1 which is powered by one of two types of battery, either utilizing one or more of the standard dry cell disposable variety or using a battery or batteries of a rechargeable nature.

3. The nutcracker tool as claimed in claim 1 wherein the safety device includes a safety cover interlock mechanism such that the safety cover can operate a mechanical linked electrical safety cut out switch to stop the motor.

4. The nutcracker tool as claimed in claim 3 which has the safety cover interlock mechanism configured to allow the withdrawal of the piston in a safe manner with the safety cover removed.

5. The nutcracker tool as claimed in claim 2 which, if fitted with a rechargeable battery or batteries, is adapted to be recharged by an external mains battery charger/dc supply unit, connected either by direct connection or inductive loop using an indicator to determine the state of the battery charge/charging.

6. The nutcracker tool as claimed in claim 1 which is made to disassemble in part, to facilitate cleaning; the internal moving parts would be made less easy to dismantle for safety reasons.

7. The nutcracker tool as claimed in claim 1 which is fitted with a torque-limiting device to the motor or gearbox such to either stop or allow slippage of the motor drive if a preset torque is exceeded.