GB2421539A

GB2421539A - Plug-in latch to retain pivoted armrest

Info

Publication number: GB2421539A
Application number: GB0428076A
Authority: GB
Inventors: Mark Diggins
Original assignee: Days Healthcare UK Ltd
Current assignee: Days Healthcare UK Ltd
Priority date: 2004-12-23
Filing date: 2004-12-23
Publication date: 2006-06-28
Anticipated expiration: 2024-12-23
Also published as: GB2421539B; GB0428076D0

Abstract

A locking mechanism 22 comprises a lock component 30 and a retainer component 24, the lock component 30 being receivable, at least in part, within the retainer component 24, the lock component 30 having an integral, flexible projection 32 associated therewith, the projection 32 including a latch 34 receivable within a corresponding formation 46 of the retainer component 24 to secure the lock component 30 to the retainer component 24. Preferably the locking mechanism 22 is used to secure a pivoted armrest 18 (eg for a chair 10).

Description

Locking Mechanism This invention relates to a locking mechanism suitable

for use in locking a swing away armrest of a shower chair, wheel chair, commode or the like against movement. It also relates to a swing away armrest including such a locking mechanism.

The provision of armrests which can swing or pivot from their in use, horizontal position to a position in which they are located generally vertically, typically adjacent the seat back of a seat, or a lowered position beneath the level of the seat pad, is well known in a number of applications, for example in shower chairs, commodes, wheel chairs or the like. It is desirable to be able to lock such swingable arm rests in their in use positions for safety reasons and also to enhance the rigidity and load bearing capabilities of the arm rests.

Several techniques are known for securing swingable arm rests in position. In one arrangement, a spring biassed catch member is pivotally connected to an end of the arm rest and is co-operable with a retainer member to retain the armrest in its horizontal condition.

The spring biassed catch member tends to move angularly out of its intended position with the result that it can no longer co-operate with the retainer member. An alternative arrangement makes use of a rotatable latch component engageable in a recess associated with the armrest. Such an arrangement is difficult to use and it is not always clear whether or not the armrest is properly locked in position. Both arrangements are fairly complex and expensive.

It is an object of the invention to provide a locking mechanism whereby the disadvantages described hereinbefore are of reduced effect.

According to the present invention there is provided a locking mechanism comprising a lock component and a retainer component, the lock component being receivable, at least in part, within the retainer component, the lock component having an integral, flexible projection associated therewith, the projection including a latch receivable within a corresponding formation of the retainer component to secure the lock component to the retainer component.

When used with a swingable armrest, the lock component is conveniently secured to the armrest. For example, the lock component may include a region arranged to be permanently received within a hollow part of the armrest.

Conveniently, the flexible projection includes, at its end, a portion which extends from the retainer component, manipulation of the said portion moving the latch out of engagement with the said formation to allow removal of the lock component from the retainer component.

The invention further relates to a swingable armrest pivotally connected to a body, and a locking mechanism as described hereinbefore for securing the armrest against movement relative to the body.

The invention wifi further be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic view of a chair including a swingable armrest and a locking mechanism in accordance with one embodiment of the invention; Figure 2 is an isometric view of the locking mechanism; and Figures 3 and 4 are views of the lock component and retainer component of the locking mechanism, respectively.

Figure 1 illustrates in, in very diagrammatic form, part of a chair comprising a seat back 10 fitted with a padded back rest 12. The seat further comprises a seat support 14 arranged to extend generally horizontally in use, the seat support 14 carrying a seat pad 16.

Pivotally connected to the seat back 10 is an armrest support 18 which carries a padded armrest pad 20. At its end remote from its pivotal connection to the seat back 10, the armrest support 18 is bent so as to include a downwardly extending region, the lower end of which carries part of a locking mechanism 22 for use in locking the armrest in its substantially horizontal condition, in use.

In Figure 1, the chair is shown with the armrest pivoted upwardly by a relatively small angle from its in use position. The invention may also be used in other configurations, for example in which the armrest is intended to be swung downwards away from its in use position.

The chair illustrated diagrammatically in Figure 1 could form part of a wheelchair, a commode, a shower seat or a range of other similar chairs.

Figure 2 illustrates the locking mechanism 22 in greater detail. The locking mechanism 22 comprises a retainer component 24 comprising a cup 26 integrally formed with saddle arrangement 28 arranged to be located over and permanently secured to part of the seat support 14. The locking mechanism 22 further comprises a lock component 30 arranged to be received, at least in part, within the cup 26. As shown more clearly in Figure 3, the lock component 30 includes an integral, flexible projection 32 upon which a latch member 34 is formed. The free end of the projection 32 is provided an enlarged region 36, a surface of which is provided with ribs 38 arranged to assist in gripping or manipulation thereof by a user. As illustrated, the latch member 34 is shaped to define a ramped surface 40 and a surface 42 which extends in a plane substantially normal to the axis of the end part of the armrest support 18.

Referring once again to Figure 2, the cup 26 is provided with a region 44 shaped to receive part of the projection 32, the region 44 being shaped to define an opening 46 adapted to receive the latch member 34, in use, the surface 42 of the latch member 34 bearing against a part 48 of the region 44 defining the top of the opening 46.

In use, the upper end region 50 of the lock component 30 is received within the hollow end of the armrest support 18 and secured in position using, for example, rivets or screws. If the armrest is initially in the position illustrated in Figure 1 and it is desired to move the armrest to its in use position, then the armrest is pivoted downwardly to cause part of the lock component 30 to be received within the cup 26. As this movement takes place, the ramped surface 40 of the latch member 34 will move into engagement with part 48 of the cup 26 causing the projection 32 to flex towards the remainder of the lock component until the armrest reaches its in use position at which point the projection 32 will spring back to its original position, the latch member 34 being received within the opening 46.

Once in this position, engagement between the surface 42 of the latch member 34 and the adjacent part 48 of the cup 26 prevents the lock component 30 from being removed from the retainer component 24, thereby locking the armrest in its in use position.

If it is desired to swing the armrest out of its in use position, then the projection 32 is pushed, using the region 36 thereof, towards the remainder of the lock component 30 to disengage the surface 42 of the latch member 34 from the adjacent part 48 of the cup 26 and thereby allow the lock component 30 to be withdrawn from the cup 26. Once withdrawn from the cup 26, the projection 32 can be released, the projection 32 springing back to its original condition.

Figure 4 is a view of a retainer component 24 very similar to the retainer component of the locking mechanism 22 shown in Figure 2, but in which the saddle 28 is located on the opposite side of the cup 26 to allow use of the retainer component 24 on the opposite side of the chair with which the locking mechanism is used.

One advantage of the invention is that, during movement of the armrest towards its in use position, the initial engagement of the lock component 30 within the cup 26 results in the latch member 34 being guided to its position in which it locks the lock component 30 to the retainer component 24. As a result, the risk of miss-use of the locking mechanism is avoided.

It is envisaged that the components of the locking mechanism can be moulded from a suitable plastics material thereby resulting in an arrangement which is relatively light in weight, resistive to corrosion which is advantageous where the seat with which the locking mechanism is used is likely to be used in wet or damp conditions, and also inexpensive.

It will be appreciated that a range of modifications and alterations may be made to the specific arrangement shown and described hereinbefore, and the invention is not restricted to the specific arrangement illustrated and described, but rather encompasses all such modifications within the scope of the claims appended hereto.

Claims

Claims 1. A locking mechanism comprising a lock component and a retainer

component, the lock component being receivable, at least in part, within the retainer component, the lock component having an integral, flexible projection associated therewith, the projection including a latch receivable within a corresponding formation of the retainer component to secure the lock component to the retainer component.
2. A mechanism according to Claim 1, wherein the lock component is securable to a swingable armrest.
3. A mechanism according to Claim 2, wherein the armrest includes a hollow region, the lock component including a region arranged to be permanently received within the hollow region.
4. A mechanism according to any one of the preceding claims, wherein the flexible projection includes, at its end, a portion which extends from the retainer component, manipulation of the said portion moving the latch out of engagement with the said formation to allow removal of the lock component from the retainer component.
5. A mechanism according to any one of the preceding claims, wherein the latch includes a ramped surface co-operable with part of the retainer component, upon introduction of the lock component into the retainer component, to cause deflection of the projection.
6. A locking mechanism substantially as hereinbefore described with reference to the accompanying drawings.
7. A swingable armrest pivotally connected to a body, and a locking mechanism as claimed in any one of the preceding claims arranged to allow the armrest to be secured against movement.
8. An armrest according to Claim 7, wherein the body forms part of a chair, commode, shower seat or wheelchair.