GB2529882A

GB2529882A - Safety system

Info

Publication number: GB2529882A
Application number: GB1415774.7A
Authority: GB
Inventors: Ben Woodling
Original assignee: Kenwood Ltd
Current assignee: Kenwood Ltd
Priority date: 2014-09-05
Filing date: 2014-09-05
Publication date: 2016-03-09
Anticipated expiration: 2034-09-05
Also published as: GB2529882B; GB201415774D0

Abstract

A safety system, especially systems for electrically operated kitchen appliances such as blenders and food processors comprising an implement intended to be motor driven and rotate within a container. The safety system comprises an attachment having a first component 12 including said implement, such as blades 20, and coupling means 22 for picking up the motor drive and a second component for selective fitting to said container, thereby to permit said implement to rotate therein. The first and second components are adapted for relative sliding movement along the rotational axis of said implement and further comprise resilient means, such as spring 24a, 24b & 24c configured to urge said first component in a direction preventing said coupling means from picking up said motor drive. The arrangement being such that correct fitting of said attachment to said container produces a force overcoming said resilient urge and moving said first component relative to said second component to enable said drive coupling to pick up said motor drive. Said container may comprise a bottomless goblet. The first and second components of said attachment may be retained together my means of snap-fit fixtures.

Description

SAFETY SYSTEM

This invention relates to safety systems and it relates especially, though not exclusively, to such systems for electrically operated kitchen s appliances such as blenders, food processors and the like.

Many appliances used in the kitchen can be fitted with attachments or accessories which contain cutting or maccrating knives or blades rotatable at reasonably high speeds by means of powerful electric motors and thus can present significant risk to users, as well as to children and others who may interfere with unattended appliances, unless appropriate safety measures are incorporated.

Most kitchen appliances manufactured by reputable companies have safety systems intended to protect users, and others, from accidental contact with rotating knives or blades, and most existing systems work reasonably well under most circunstances. However, there is a continual quest for safely systems exhibiting improved ease of usage, reliabilily, security and/or robustness. Such systems should preferably be economical to manufacture in large quantities and thus many requirements, some of them conflicting, are imposed upon their design and manufacture.

It will be appreciated that, since the attaclunents, such as blade assemblies for blender goblets, are not themselves connectable to an electricity supply, it is desirable that the safety system is mechanically operated, thus making the attachments intrinsically safe.

The invention aims to provide an electrically powered kitchen appliance incorporating an improved safety system.

s According to the invention there is provided a safety system for an attachment comprising an implement intended to be motor driven and to rotate within a container; the attachment comprising a first component including said implement and coupling means for picking tip the motor drive therefor and a second component adapted for selective fitting to said container, thereby to permit said implement to rotate therein; the first and second components being adapted for relative sliding movement along the rotational axis of said implement, and further comprising resilient means configured to urge said first component in a direction preventing said coupling means from picking up said motor drive; the arrangement being such that correct fitting of said attachment to said container produces a force overcoming said resilient urge and moving said first component relative to said second component to enable said drive coupling to pick up said motor drive.

Preferably, the container comprises a bottomless goblet having a base side-wall adapted to be located in place arommd said implement and fitted to said second component by a readily releasable and securable means such as screw threads or a bayonet fixing. By this means, the attachment can be utilised with different goblets.

In preferred embodiments of the invention, the first component of the attachment comprises a blade assembly fitted with one or more blades intended to rotate within said container thereby to process foodstuffs or other materials therein.

It is further preferred that the means associated with said container for s producing said force overcoming said resilient urge comprises the lower rim of the side-wall of said bottomless goblet which, when the goblet is screwed or otherwise located into place, engages a shoulder member of said first component.

The first and second components of said attachment are preferably retained together by means of snap-fit fixtures engaging into apertures sized to accommodate said relative sliding movement.

It is further preferred that said first and second components of the attachment are formed with complementary linear guide members configured to pennit said relative sliding movement but to resist rotational movement between the first and second components.

The invention also encompasses a kitchen appliance incorporating a safety system in accordance with any of the foregoing.

In order that the invention may be clearly understood and readily carried into effect, one embodiment thereof will now be described with reference to the accompanying drawings, of which: Figure 1 shows, in exploded view, blade assembly and main base housing components of a safety system in accordance with one embodiment of this invention; S Figure 2 shows, in cross-sectional view, the components illustrated in Figure 1 assembled together to provide an attachment intended for fitrnent to the base of an open-bottomed goblet; Figure 3 shows an underside elevation of the blade assembly; and Figure 4 shows, in cross-sectional view, the attachment assembled to a goblet.

Referring now to the drawings, the components of the system to be described comprise an integral part of a base attachment 10, including a blade assembly 12, which can be connected in known maimer, for example by way of a screw or bayonet comiection, to a bottomless goblet 14 (Figure 4), so as to form the base of the goblet. By this means, the goblet 14 with its base attachment 10, including the blade assembly 12, can be placed upon, and the blade assembly 12 driven by, a rotational drive outlet presented by a free-standing base unit (not shown) of a domestic electrical appliance, in this case a liquidiser/blender; the base unit housing an electrical motor and associated circuitry and controls to power the outlet at a desired speed. The electric motor may be of any type convenient and suitable for use in the context of the appliance in question.

S

In order to pick tip the drive from the outlet on the base unit, the blade assembly 12 of the base attachment 10 is provided with a drive socket 16 which mates with the drive outlet and rotates a shaft 1 8 which carries the blades such as 20 of the assembly 12.

S

The base attachment 10 comprises two main components, the blade assembly 12 and a main base housing 22; these components being mounted for relative axial motion, along the line of the drive shaft 18, under the influence of resilient means such as springs 24a, 24b and 24c, for a reason that will become clear shortly. The springs are mounted on corresponding pins and/or sockets as is well known.

The main base housing 22 is provided with the means, such as screw threading 26, to attach it (together with the blade assembly 12) to corresponding screw thread 28 formed at the open bottom 30 of the goblet 14.

In order to ensure that the blades 20 of the assembly 12 cannot be rotated by the drive outlet on the base unit unless the attachment 10 is securely fitted to the goblet 14, the aforementioned spring-loaded axial motion of the blade assembly 12 relative to the main base housing 22 of the attachment 10 is constructed so that the springs 24a, 24b and 24c urge the blade assembly sufficiently far into the main base housing 22 that the drive socket 16 cannot couple with the outlet on the free-standing base unit. Thus, even if the attachment 10 should be placed alone on the base unit and directly over the drive outlet thereon, the blades 20 cannot be driven as the necessary drive coupling is not made.

When the main base housing 22 of the attachment 10 is screwed into the open base 30 of the goblet 14, however, a lower lip 32 at the open base 30 of the goblet engages with and presses down on a shoulder 34 of the s blade assembly 12, thereby urging the blade assembly downwards relative to the main base housing 22 and, when the coupling of the goblet 14 to the attachment 10 is fully secure, the drive socket 16 of the blade assembly 12 is lowered sufficiently relative to the main base housing 22 to allow it to couple with the drive outlet on the base unit. It will be appreciated that a seal 36 is provided between the lip 32 and the shoulder 34.

By this means, a reliable and purely mechanical safety system is provided which allows the bladed member 12 to be driven only if the attachment 10 as a whole is properly fitted into the base of a suitable receptacle such as the goblet 14, and the blades 20 are thus not exposed.

As will be appreciated, the goblet 14 will usually be provided with a lid (not shown) and a further safely system may then be provided to prevent rotation of the blades 20 unless the lid is securely in place.

The springs 24a, 24b and 24c are preferably disposed with equi-angular spacing so as to provide an even force distribution, and the resilient force they apply to the blade assembly 12 is arranged to be sufficient to prevent accidental depression of the blade assembly 12 relative to the main base housing 22 to an extent that could permit drive coupling engagement.

The act of securing the goblet 14 correctly to the main base housing 22 of the attachment 10 utilises the mechanical advantage of the thread or bayonet form to overcome the spring force and lower the blade assembly 12, and thus the drive socket 16, sufficiently to permit driving S engagement of the socket 16 with the drive outlet on the base unit of the appliance.

In order to permit the required axial sliding action of the blade assembly 12 relative to the main base housing 22, the blade assembly 12 is, in this embodiment of the invention, provided with four guide ribs such as 38 which co-operate with complementary components such as 40 formed in the main base housing 22. This allows the required sliding movement, whilst at the same time resisting rotation and excessive lateral movement.

These ribs 38 also serve to reduce the possibility that the blade assembly 12 might catch on the threading 26 of the main base housing 22.

hi order to retain the two components 12 and 22 of the attachment 10 against the spring force four cantilever snap fit clips such as 42 are provided on the blade assembly, to engage into elongate slots 44 on the housing 22; this arrangement further providing ease of assembly and economy of required components.

It will be appreciated that the system as described herein provides protection not only in circumstances where the attachment 10 is placed, absent the goblet 14, over the drive outlet of the base unit of the appliance and the electric motor is actuated by mischievous, malicious or inadvertent operation of a power switch, but also in circumstances where a short circuit or other electrical mischance or breakdown actuates the motor independently of the power switch.

This invention can be used in association with the drive centralising S arrangement described and claimed in our co-pending patent application (Agent's Ref P43585GB) of even filing date herewith.

Claims

CLAIMS: 1. A safety system for an attachment comprising an implement intended to be motor driven and to rotate within a container; the s attachment comprising a first component including said implement and coupling means for picking tip the motor drive therefor and a second component adapted for selective fitting to said container, thereby to permit said implement to rotate therein; the first and second components being adapted for relative sliding movement along the rotational axis of said implement, and further comprising resilient means configured to urge said first component in a direction preventing said coupling means from picking up said motor drive; the arrangement being such that correct fitting of said attachment to said container produces a force overcoming said resilient urge and moving said first component relative to said second component to enable said drive coupling to pick up said motor drive.
2. A system according to claim 1, wherein the container comprises a bottomless goblet having a base side-wall adapted to be located in place around said implement and fitted to said second component by a readily releasable and securable means, such as screw threads or a bayonet fixing.
3. A system according to claim I or claim 2, wherein the first component of the attachment comprises a blade assembly fitted with one or more blades intended to rotate within said container thereby to process foodstuffs or other materials therein.
4. A system according to any preceding claim, wherein the means associated with said container for producing said force overcoming said resilient urge comprises the lower rim of the side-wall of said bottomless S goblet which, when the goblet is screwed or otherwise located into place, engages a shoulder member of said first component.
5. A system according to any preceding claim, wherein the first and second components of said attachment are retained together by means of snap-fit fixtures engaging into apertures sized to accommodate said relative sliding movement.
6. A system according to any preceding claim, wherein said first and second components of the attachment are formed with complementary linear guide members configured to permit said relative sliding movement but to resist rotational movement between the first and second components.
7. A safety system substantially as herein described with reference to and/or as shown in the accompanying drawings.
8. A kitchen appliance incorporating a safety system in accordance with any preceding claim.Amendments to the claims have been filed as follows CLAIMS: 1. A safety system for an attachment comprising an implement intended to be motor driven and to rotate within a container; the s attachment comprising a first component including said implement and coupling means for picking tip the motor drive therefor and a second component adapted for selective fitting to said container, thereby to permit said implement to rotate therein; the first and second components being adapted for relative sliding movement along the rotational axis of said implement, and further comprising resilient means configured to urge said first component in a direction preventing said coupling means IC) from picking up said motor drive; the arrangement being such that correct fitting of said attachment to said container produces a force overcoming said resilient urge and moving said first component relative to said second component to enable said dnve coupling to pick up said motor drive, wherein the first and second components of said attachment are retained together by means of snap-fit fixtures engaging into apertures sized to accommodate said relative sliding movement.2. A system according to claim, wherein the container comprises a bottomless goblet having a base side-wall adapted to be located in place around said implement and fitted to said second component by a readily releasable mid securable means, such as screw threads or a bayonet fixing.3. A system according to claim I or claim 2, wherein the first component of the attachment comprises a blade assembly fitted with one or more blades intended to rotate within said container thereby to process foodstuffs or other materials therein.4. A system according to any preceding claim, wherein the means s associated with said container for producing said force overcoming said resilient urge comprises the lower rim of the side-wall of said bottomless goblet which, when the goblet is screwed or otherwise located into p'ace, engages a shoulder member of said first component.5. A system according to any preceding claim, wherein said first and second components of the attachment are formed with complementary UD linear guide members configured to permit said relative sliding movement but to resist rotational movement between the first and second components.6. A safety system substantially as herein described with reference to and/or as shown in the accompanying drawings.7. A kitchen appliance incorporating a safety system in accordance with any preceding claim.