GB2267531A - Locking device for a folding bed - Google Patents

Abstract

A locking device for a folding bed comprises a detent pin 11 and a latch arm 6 pivoted to a mounting plate 1, and a spring 7. The mounting plate 1 is mounted to a first member of the bed, and the pin 11 to a second member, such that on moving the members into a predetermined orientation, camming action between the pin 11 and the arm 6 depresses the arm, and allows the pin to enter a slot 16 latching the first and second bed members together under the action of spring 7. A handle 12 is provided for unlatching. <IMAGE>

Description

LOCKING DEVICE FOR A FOLDING BED This invention relates to a locking device for a folding bed and particularly, but not exclusively, to a locking device for a folding bed of the kind having a base supported by legs each of which is pivoted for fdlding.

In a bed of the kind set forth the legs typically unfold through an angle greater than 90" so that, in the operative position they are at a slight slant in relation to the vertical. In such a case the load borne by a leg in use normally urges it against a stop on the base to prevent the leg returning to its folded condition. However in certain circumstances, for example due to a sudden movement by a person on the bed, one or more of the legs could be urged away from its slanted condition and past the vertical, so as to result in inadvertent folding and the possibility of injury to the user or damage to the bed.

According to the present invention a locking device for a folding bed comprises detent means, a latch arm, and biassing means acting on the latch arm, the latch arm having a first portion serving as a manually operable lever, and a second portion having a camming surface and retaining means for engagement with the detent, and being pivoted to a first member of the bed about a pivot located at an intermediate position between the first and second portions and the detent means being fixed to a second member of the bed, and being engageable with the camming surface by relative movement between the first and second members of the bed so as to pivot the latch against the action of the biassing means, and being engageable with the retaining means by the action of the biassing means following the engagement with the camming surface, so as to prevent relative movement between the first and second members of the bed, the engagement between the detent means and the retaining means being releasable by the operation of the first portion of the latch arm in a direction against the action of the biassing means.

Preferably the biassing means is in the form of a spring.

Preferably the biassing means urges the latch arm against a stop prior to engagement between the latch arm and the detent.

Preferably the biassing means, stop and pivot for the latch arm are borne on a mounting plate which is fixed to the first member of the bed, the mounting plate also having a hole for location of pivot means which connect the first and second members of the bed.

Preferably the first member is part of the base of the bed, the second member being a bed leg. However, the first member could be a leg and the second member part of the base.

The detent means may be any suitable projection, such as a hook or U-shaped bolt, but is preferably in the form of a pin having a substantially circular section.

Preferably the retaining means is in the form of a slot in the latch arm having a closed end and an open end for entry of the detent means into the slot.

Preferably the slot is oriented in a direction substantially tangential to a circle centred on the latch arm pivot and passing through the slot. However, the slot may be of arcuate form.

By way of example only, an embodiment of the invention will now be described with reference to the accompanying drawings in which: Figure 1 shows an assembly of components for a locking device in accordance with the invention, Figure 2 shows the mounting plate for the assembly of Figure 1, Figure 3 shows the flat plate from which the catch arm for the assembly of Figure 1 is made, Figure 4 shows a plan view of the catch pin bracket for the assembly of Figure 1, and Figure 5 shows a side view of the catch pin bracket.

Referring to Figures 1 and 2 the embodiment is particularly suited to use for a folding bed having a timber frame, and consequently the mounting plate 1 is provided with a pair of countersunk holes 2 for fastening to the wooden bed base using self-tapping screws. A third hole 3 is provided at one end of the mounting plate for location of a pivot for one of the legs of the bed which is conveniently in the form of a bolt, screw or similar pivoting means.

At an intermediate portion of the mounting plate are a pair of pins 4, 5. The catch arm 6, shown in Figures 1 and 3, is freely pivoted on the first pin 4 which passes through a hole 7 in the catch arm 6 and has an oversize head to prevent the catch arm from separating from the mounting plate. The second pin 5 on the mounting plate serves as a stop to hold the catch arm in a suitable position prior to latching.

Adjacent an upper edge of the mounting plate 1 is a small tab 10 projecting from the surface of the mounting plate, which serves as an attachment point for one end of a spring 7, see Figure 1.

Figures 4 and 5 show the catch pin bracket. This comprises a base plate 8 provided with a pair of countersunk holes 9 for attachment to the side of a wooden bed leg using self-tapping screws, and a pin 11 projecting from the base plate which is held by the catch arm 6 when the leg is in its fully open position in order to prevent inadvertent collapse of the leg.

The remaining features of the catch arm 6 can be seen in Figure 1, and in Figure 3 which shows the flat plate from which the catch arm is made. At one end of the plate in Figure 3 is a tab 12 which, in the developed form of the catch arm in Figure 1, is bent at approximately right angles to the rest of the arm to form a release lever 13.

During operation of the locking device a leg of the bed is pivoted from its closed position, lying parallel to the base of the bed, to an open position by rotating about the pivot through the upper end of the leg which is located by the hole 3 in the mounting plate. The opening movement brings the catch pin 11 on the side of the leg into initial engagement with the camming surface 14 provided by the curved end of the catch arm 6. As the opening of the leg continues the camming action of the pin 11 on surface 14 depresses the adjacent end of the lever against the action of the spring 7 which is attached to the catch arm 6 at 15.

When the catch arm is depressed sufficiently the catch pin 11 reaches a position at the mouth of a slot 16 situated at the end of the camming surface 14, and the action of the spring 7 will then raise the catch arm again so that the catch pin 11 enters the slot 16. Location of the pin in the slot prevents the leg from being opened further, or from closing, so that the leg will not fold unintentionally while the bed is in use.

In order that the leg can be closed again so as to fold the bed for storage purposes, the catch pin 11 can be released from the slot 16 in the catch arm 6 by pulling upwards on the release lever 13 against the action of the spring 7.

In an alternative arrangement, the legs of the bed are joined rigidly in pairs by cross bars. Whilst both legs of a pair are pivoted to the base of the bed, it is then necessary for only one of them to be provided with a locking device in accordance with the invention.

Whilst the invention has been described with reference to what is presently considered to be the preferred embodiment of the invention, various other embodiments and arrangements falling within the scope of the invention will be apparent to a reader skilled in this field.

Claims (11)

1. A locking device fdr a folding bed comprising detent means, a latch arm, and biassing means acting on the latch arm, the latch arm having a first portion serving as a manually operable lever, and a second portion having a camming surface and retaining means for engagement with the detent, and being pivoted to a first member of the bed about a pivot located at an intermediate position between the first and second portions and the detent means being fixed to a second member of the bed, and being engageable with the camming surface by relative movement between the first and second members of the bed so as to pivot the latch against the action of the biassing means, and being engageable with the retaining means by the action of the biassing means following the engagement with the camming surface, so as to prevent relative movement between the first and second members of the bed, the engagement between the detent means and the retaining means being releasable by the operation of the first portion of the latch arm in a direction against the action of the biassing means.

2. A locking device for a folding bed as claimed in claim 1, in which the biassing means is in the form of a spring.

3. A locking device for a folding bed as claimed in claim 1 or claim 2, in which the biassing means urges the latch arm against a stop prior to engagement between the latch arm and the detent.

4. A locking device for a folding bed as claimed in claim 3, in which the biassing means, stop and pivot for the latch arm are borne on a mounting plate which is fixed to the first member of the bed, the mounting plate also having a hole for location of pivot means which connect the first and second members of the bed.

5. A locking device for a folding bed as claimed in any one of the preceding claims, in which the first member is part of the base of the bed, the second member being a bed leg.

6. A locking device for a folding bed as claimed in any one of claims 1 to 4, in which the first member is a bed leg and the second member part of the base of the bed.

7. A locking device for a folding bed as claimed in any one of the preceding claims, in which the detent means is in the form of a pin having a substantially circular section.

8. A locking device for a folding bed as claimed in any one of the preceding claims, in which the retaining means is in the form of a slot in the latch arm having a closed end and having an open end for entry of the detent means into the slot.

9. A locking device for a folding bed as claimed in claim 8, in which the slot is oriented in a direction substantially tangential to a circle centred on the latch arm pivot and passing through the slot.

10. A locking device for a folding bed substantially as described herein with reference to the accompanying drawings.

11. A folding bed provided with a locking device as claimed in any of the preceding claims.