GB2440198A

GB2440198A - Improvements in drop-side cot locking mechanisms

Info

Publication number: GB2440198A
Application number: GB0613919A
Authority: GB
Inventors: Michael William Lusty
Original assignee: LINKED RESOURCING Ltd
Current assignee: LINKED RESOURCING Ltd
Priority date: 2006-07-13
Filing date: 2006-07-13
Publication date: 2008-01-23
Anticipated expiration: 2026-07-13
Also published as: GB2440198B; GB0613919D0

Abstract

Single-handed locking mechanisms for drop-side cots are known in which the cot side has to be raised and the lower end thereof has to be moved laterally in order to unlock the cot side and move it from an upper to a lower position. The present invention provides a drop-side cot 1 locking mechanism, whereby the cot side 16 has to be raised and the upper end thereof has to be moved laterally in order to unlock the cot, side and move it from an upper to a lower position. Members 140, 144 on the cot side engage a guide track 150 and a pin 142 disengages from a locking section 155 when the upper end of the side is raised then moved laterally. To permit the lateral movement the member 140 can be located on an arm pivoted to the cot side or can be slidable in a transverse slot; alternatively the track 150 can be resilient. In another embodiment a hook on rail 18 engages over a hook on upright 112 and slides on rod mounted along upright 112. The upper end of the rod can move laterally to allow the hooks to disengage. A method of releasing and moving a slidable side frame of a drop-side cot from a locked upper position to a lower is also provided.

Description

IMPROVEMENTS IN DROP-SIDE COT LOCKING MECHANISMS

This invention is concerned with improvements in drop-side cot locking mechanisms. It is also concerned with a method of releasing and moving a slidable side frame of a drop-side cot.

Figures 1 to 6 of the attached drawings illustrate the general arrangement of known types of cot. With reference to Figure 1, cots 1 typically comprise a base frame 14, two end frames 10 and two side frames 16. The end frames 10 and side frames 16 have bars 11, extending between upper rails 18 and lower rails 19. The spacing of the bars 11 is chosen so that an infant placed in the cot cannot escape from the cot by passing between the bars. The base frame 14, upon which a mattress 20 rests, is typically only fixed to the end frames 10 for the reason which will be explained below. The term cot include cotbeds.

In order to facilitate access and to reduce the height of the barrier over which an adult has to reach to place an infant into the cot it is possible to make at least one side frame 16 slidable relative to the two end frames 10, between upper and lower positions. The cot side can thus be lowered when an adult wishes to place an infant into, or remove an infant from, the cot, and raised when the infant is in the cot so that it cannot climb out of the cot. To ensure that an infant cannot inadvertently, or deliberately, move the slidable side frame to its lower position locking mechanisms are provided which allow the side frame to be releasably locked in an upper position.

Bolts or screws 22 are typically employed to hold the end frames together via the non-slidable side frame 16. This is also true for the junction of the base frame 14 and end frames 10. However, with regard to the slidable side frame, such bolts or screws 22 cannot be used, since they would not allow the side frame 16 to slide relative to the two end frames 10. Therefore to provide structural integrity at these points guide slots 24 and mushroom-headed pins 26 have been used, as illustrated in Figure 2. This arrangement ensures that the cot I will endure the application of lateral force since the two end frames 10 are linked together via the slidable side frame 16 through the slots 24 and pins 26.

To maintain the slidable side frame in the raised position, in this type of drop-side cot, catches 28 in the form of hooks are provided at the upper end of each leg 12.

The catches 28 are pivoted at a pivot point 29 and engage underneath the guide pins 26 to retain them in a hooked end 30. An example of such a catch is known from GB1 118984 and illustrated in Figure 3.

To lower the slidable side frame 16 in this type of cot it is necessary to release both catches 28, at either end of the upper rail 18 of the slidable side frame 16, simultaneously. Since the length of the upper rail 18 separates the two catches 28 it is necessary to use two hands to release them simultaneously. Accordingly, it is very difficult, if not impossible, to release both the catches, and thus unlock the slidable side frame 16, while also safely holding an infant. To overcome this problem an alternative drop-side cot with a so called single-handed locking mechanism' has, in the past, been developed. Figure 4 illustrates the structure of a drop-side cot with a so-called single-handed locking mechanism.

On the left hand side of Figure 4 a side view of a leg 12 of an end frame 10 is shown. At an upper portion of this leg 12 an upper guide track 50 is provided and at a lower portion a lower guide track 54 is provided. On the right hand side of Figure 4 a side view of a side frame 16 having an upper rail 18 and bars 11 is shown. On the end of the side frame, for interaction with the upper guide track 50, a guide member 40, in the form of a stud having a neck or shaft 41 and a mushroom head 43 (refer to Figure 5) is provided. This guide member 40 is fixed to the side frame 16 so that it cannot move relative to the side frame 16.

With reference to Figure 5, which is a cross-sectional view of part of a leg 12 and side frame 16, the upper guide track 50 takes the form of a slot, formed within the leg 12, having a narrow entrance, through the surface of the leg 12, behind which a wider channel 51 lies. The upper guide track 50 and guide member 40 interengage such that the head 43 of the stud may travel along the length of the channel 51 but be retained therein. To introduce the head 43 of the stud into the wider channel an access point 52 (see Figure 4) is provided in the guide track 50. The head 43 is typically round in shape to allow it to travel along the guide track as easily as possible. This round shape is not seen in Figure 5 as only a side view is shown.

A headless guide pin 42, for interaction with the lower guide track 54, is provided on the same end of the side frame 16 as guide member 40 but at a lower portion thereof. In use, the side frame 16 is guided during lowering and raising by the interengagement of guide member 40 and upper guide track 50, and of guide pin 42 and lower guide track 54.

With regard to the structural integrity of a cot of this type, the upper ends of the end frames 10 are connected to each other via the slidable side frame by means of the interengagement of the guide members 40 and upper guide tracks 50 provided on each end of the side frame. This is because the heads 42 of the members are only able to move upwardly and downwardly, relative to the guide track 50, and not laterally, other than at access point 52.

Referring to the left hand side of Figure 4, the lower guide track 54 has a straight section and a curved upper section such that it resembles a question mark "?". The head 42 of the guide member 40 travels within this guide track 54 between lower and upper positions.

To lock the side frame 16 in the raised position relative to the end frame 10, the side frame 16 is raised such that the headless guide pin 42 travels up the lower guide track 54 and the mushroom-headed guide member 40 travels up the upper guide track 50. When the pin 42 meets the leaf spring 56, positioned in the upper portion of the lower guide track 54, its travel is impeded since the spring 56 extends from one side of the track 54 to the other. However, by continued raising of the side frame 16 the guide pin 42 is urged past the spring 56. The pin 42 will then pass into the locking portion 55 of the guide track 54.

To release the side frame from this upper position involves two actions which are difficult for an infant to perform. First, the side frame 16 has to be raised such that the pin 42 is raised within the locking portion 55 until it reaches the top of the guide track 54. Second, the lower portion of the side frame has to be moved transverse its plane either towards or away from the base frame 14. To move the lower portion of the side frame towards the base frame a force is applied to the lower rail of the side frame typically with the user's leg. This movement urges the guide pin 42 past the spring 56 such that the pin 42 may then travel down the guide track 54 thus lowering the side frame 16.

This method of lowering the side frame 16 is depicted in Figure 6 where a sequence of side views of the leg 12 of the end frame 10 relative to the side frame 16 are shown. In the first view (shown on the far left of Figure 6) the side frame 16 is shown in the locked upper position. In the second view, the side frame 16 has been raised, in the direction "A", relative to the end frame 10. In the third view, the lower side of the frame 16 has been pushed in towards the cot in direction "B" such that the side frame is pivoted about the upper guide member 40, and in the last view the side frame 16 is shown having been fully lowered.

A problem with this arrangement is that within the cot a mattress 20 and bedding 21 are typically present. This mattress 20 and bedding 21 can obstruct the movement of the lower portion of the side frame 16 as it is pushed in towards the cot in the direction "B", as shown in the third view in Figure 6. Although, in theory, the arrangement of the lower guide track 54 may be reversed such that rather than unlocking the side frame by pushing the lower portion of the side frame 16 in towards the cot it is pulled away from the cot in an opposite direction, this movement would be awkward for a user to achieve since the present arrangement is designed such that the user lifts the side frame with one hand and pushes the lower portion of the side frame with his leg. These actions can be achieved with a user standing next to the cot, possibly while holding an infant in one arm.

However, it would be difficult to pull the lower portion of the side frame 16 away from the cot without using a hand. Accordingly, a user would have to crouch besides the cot to unlock the side. This would be difficult and, if the user were holding an infant at the time might risk dropping it.

There is therefore a need for an improved locking mechanism for use with drop-side cots in which the sliding side frame 16 may be released from a locked upper position and moved to a lower position by means of the use of one hand only and without the possibility of bedding 21 getting in the way.

In one aspect, the invention provides a drop-side cot locking mechanism, for use with cots having a base frame, two end frames and two side frames, at least one of said side frames being slidable, relative to the two end frames, between upper and lower positions, the locking mechanism having means for releasably locking the slidable side frame in an upper position relative to the two end frames, the means being operable to release the slidable side frame from its upper position by lifting the slidable side frame, thereby to raise it relative to the end frames, and then by moving the upper part of the slidable side frame laterally, relative to the end frames, thus allowing the slidable side frame to be lowered.

One benefit of such a locking mechanism is that the slidable side frame may be released from its locked upper position and moved to its lower position by means of one hand only. No other part of the body is required such as a leg or another hand. This is because the locking mechanism may be operated so that only one hand is required to initially raise the slidable side frame, by for instance grasping the upper rail. The same hand can then laterally move the upper portion of the slidable side frame, either towards of away from the interior of the cot, so that the side frame may be unlocked and lowered.

In one embodiment, the locking mechanism includes connecting means, the means comprising a first guide member, having engagement means, and a guide track, the engagement means being slidably retainable by the guide track, one of said guide track and said guide member being arrangeable on an end frame and the other of said guide track and said guide member being arrangeable on said slidable side frame, wherein a portion of the guide track is resiliently bendable, such that in use the connecting means slidably connects the side frame and end frame together allowing the side frame to move, relative to the end frame, in directions both parallel and perpendicular to its height, and to pivot about an axis parallel to its length, wherein the connecting means prevents the end frame moving away from the side frame in a direction parallel to the length of the side frame.

This first guide member may be arranged on the end of the frame in an upper portion thereof. In this context, "upper portion" means at least in the upper half and preferably in the upper quarter of the length of the end of the frame.

In another embodiment, the locking mechanism includes connecting means, the means comprising a first guide member, having first and second engagement means, and first and second guide tracks, the first engagement means being slidably retainable by the first guide track, and the second engagement means being slidably retainable by the second guide track, one of said first and second guide tracks being arrangeable on an end frame and the other of said first and second guide tracks being arrangeable on the slidable side frame, such that in use the connecting means slidably connects the side frame and end frame together allowing the side frame to move, relative to the end frame, in directions both parallel and perpendicular to its height, and to pivot about an axis parallel to its length, wherein the connecting means prevents the end frame moving away from the side frame in a direction parallel to the length of the side frame.

This first guide member may also be arranged on the end of the frame in an upper portion thereof. The first guide member may take the form of a shaft connecting and retaining a stud, or head, at each end.

In yet another embodiment, the locking mechanism includes connecting means, the means comprising an arm with at one end a first guide member having engagement means at one end, and being pivotable about the other end, and a guide track, the engagement means being slidably retainable by the guide track, one of said arm and said guide track being arrangeable on an end frame and the other of said arm and said guide track being arrangeable on said slidable side frame, such that in use the connecting means slidably connects the side frame and end frame together allowing the side frame to move, relative to the end frame, in directions both parallel and perpendicular to its height, and to pivot about an axis parallel to its length, wherein the connecting means prevents the end frame moving away from the side frame in a direction parallel to the length of the side frame.

The locking mechanism may also include two further guide members, each being arranged on either one of the side frame and end frame, for slidable engagement with a corresponding guide track.

One of the further two guide members may be a pin fixed to the relevant frame above the first guide member, and the other of the further two guide members may a stud, connected and retained on a shaft, fixed to the relevant frame below the first guide member.

The locking mechanism may also include resilient biasing means for biasing the pin into a portion of the guide track whereby the slidable side frame is locked in an upper position relative to the two end frames. The resilient biasing means may take the form of a leaf spring, although other forms are contemplated.

Either or both of the guide tracks may be pre-formed channels or rails for either surface mounting on, or for being counter-sunk relative to, the relevant frame.

In a further embodiment, the locking mechanism includes connecting means, the means comprising a guide member, having engagement means, and a guide rod, the engagement means being slidably retainable by the guide rod, one of said guide rod and said guide member being arrangeable on an end frame and the other of said guide rod and said guide member being arrangeable on said slidable side frame, wherein a portion of the guide rod is resiliently bendable, such that in use the connecting means slidably connects the side frame and end frame together allowing the side frame to move, relative to the end frame, in directions both parallel and perpendicular to its height, and to pivot about an axis parallel to its length, wherein the connecting means prevents the end frame moving away from the side frame in a direction parallel to the length of the side frame.

The guide member may be the upper rail of the slidable side frame and the engagement means may be a hole therethrough.

In another aspect, the invention provides a cot comprising a base frame, two end frames and two side frames, wherein at least one side frame is slidable, relative to the two end frames, between upper and lower positions, the cot including a locking mechanism, according to any preceding claim, for releasably locking the slidable side frame in an upper position.

The frames of the cot may be constructed predominantly of wood.

In a further aspect, the invention provides a method of releasing and moving a slidable side frame of a drop-side cot from a locked upper position to a lower position, wherein the cot has a base frame, two end frames, and the said side frame, and wherein the said side frame is slidable relative to the two end frames, the method comprising the steps of lifting the side frame to raise it relative to the end frames of the cot; moving the upper part of the slidable side frame laterally relative to the end frames; and lowering the side frame relative to the end frames.

The present invention and its advantages will be better understood from the preceding discussion and following detailed description in which references are made to the attached figures in which; Figure 1 is a perspective view of a known cot; Figure 2 is a perspective view of a known locking mechanism; Figure 3 is a perspective view of a known latch; Figure 4 is a side view of a known locking mechanism; Figure 5 is a cross sectional view of a known guide track and guide member; Figure 6 is a sequence of side views of a known drop-side cot with a locking mechanism in use; Figure 7 is a side view of a locking mechanism according to one embodiment of the present invention; Figure 8 is two views of a guide member in different positions relative to an associated lateral guide track; Figure 9 is a view of a swivel assembly; Figure 10 is a sequence of side views of a side frame and end frame showing the side frame being lowered from a locked upper position; Figure 11 is a side view of a locking mechanism according to another embodiment of the present invention; Figure 12 is a cross-sectional view of a box-channel; Figure 13 is another side view of the locking mechanism of Figure 11; Figure 14 is a side view of a locking mechanism according to yet another embodiment of the present invention; and Figure 15 is another two side views of the locking mechanism of Figure 14.

On the left hand side of Figure 7 a side view of a leg 112 of an end frame is shown.

On the right hand side of the Figure a side view of a slidable side frame 116 is shown. A guide track 150 is arranged on, or in, the side of the leg 112 and guide members 140, 142, 144 are provided on the end of the side frame 116. The guide members 140, 142, 144 are arranged to travel within the guide track 150.

Although shown as a continuous track, the guide track 150 may in fact be discontinuous in the manner of the prior art. Further, although the guide track 150 is shown on the leg 112 and the guide members 140, 142, 144 are shown on the side frame 116, this situation may be reversed so that the guide members are arranged on the leg 112 and the guide track 150 is arranged on the side frame 116.

The guide track 150 takes the form of a question mark "?" in that it has a substantially straight length with a curved portion. This deviates to the right and then back to the left before ending in a locking portion 155, similar to the known locking portion described above, which is lower than the top of the curved portion.

The physical characteristics of the guide track are similar to the known guide track as described above. In other words, the track has a narrow entrance leading to a recessed wider portion 151 in a similar manner to that shown in Figure 5. This track may be a surface mounted or counter-sunk pre-formed channel or may be formed within and from the constituent material of the leg 112 or may be a combination of the two. In order that the head portions of the guide members 140, 144 may be fitted to the wider recessed portion 151 of the guide track 150, access points 152 are provided. These access points allow the heads of the guide members 140, 144 to pass beyond the narrow opening at the entrance of the track and into the wider slot 151 behind. These access points are arranged such that the side frame 116 and end frame, or leg 112, may be fitted together during erection of the cot. However, the linear spacing of the access points and the linear spacing of the two guide members are carefully chosen so that guide member 140 cannot be at the upper access point 152 at the same time that guide member 144 is at the lower access point 152. This prevents the side frame 116 and end frame from coming apart and ensures that the two frames are always maintained together during normal use and especially when the side frame is in either of its two stable positions relative to the end frame. For instance, when the side frame 116 is in the raised locked position the guide member 140 is located above the upper access point 152 and the guide member 144 is located above the lower access point 152.

Further, when the side frame 116 is in the fully lowered position, the lower guide member 144 rests against the bottom of the guide track 150 so that it is well below the lower access slot 152 and the upper guide member 140 is located below the upper access point 152.

Guide member 142 is in the form of a pin which may travel within and along the guide track 150. The pin is not retained in the guide track 150 unlike the guide members 140, 144 since it does not have a head and is not in the form of a mushroom-headed stud. However, the pin may not leave the confines of the guide track due to the closely spaced relationship of the end frame and side frame 116.

This closely spaced relationship is due to the retaining function of the guide members 140, 144 and guide track 150 as discussed above.

To raise the side frame from the lower position the upper rail 118 is grasped and lifted. This causes the pin 142 and guide members 140, 144 to travel upwards along the guide track 150. The pin travels along the guide track 150 until it reaches the resilient member 156. At this point, further urging of the side frame 116 will allow the pin 142 to pass the resilient member 156. As the pin 142 passes the resilient member 156, which takes the form of a leaf spring in the embodiment shown in the Figures, it is urged into the locking portion 155, by the resilient member 156. If the side frame is then released it will drop slightly relative to the end frame (or leg 112). In this position, the side frame 116 is locked in an upper position relative to the end frame.

The guide pin 142 and lower guide member 144 are fixed relative to the side frame 116. However, the upper guide member 140 may move laterally with respect to the side frame 116. This lateral movement allows the side frame to pivot about the lower guide member 144 so that the guide pin 142 may travel around the partially circular portion of the guide track 150.

In Figure 7 the upper curved portion of the guide track 150 is illustrated as being narrower than the straight portion. This is because the upper portion is only occupied by the guide pin 142 and not the guide members 140, 144. Guide pin 142 has a smaller overall diameter than the diameter of the heads of the guide member 140, 144 and therefore requires a narrower track. One of the reasons why a pin is used to engage with the upper curved portion of the guide track is that if a guide member with a head were used instead the guide track 150 would have to be wider and occupy more of the width of the leg 112. Since cot legs are commonly made from wood the margins between the guide track and the sides of the leg 112 have to be maintained to ensure that the leg and guide track are strong enough and that the wood does not split caused by the guide track being too close to the sides of the leg 112. Therefore, if the width of the track were increased to cater for a mushroom-headed guide member then the width of the leg 112 in the region of the curved upper portion would have to be correspondingly wider which would increase cost, materials and weight. However, if the leg was made wider, or different material was used, there is no reason why the pin 142 could not be replaced by another headed guide member.

Figure 8 is a sequence of two views of the end of the slidable side frame 116 illustrating the upper guide member 140. The guide member 140 has an outer head which fits into and may travel along the guide track 150, as described above. It also has an inner head or stud 141 which travels in its own lateral guide track 148.

This guide track 148 is of a similar construction to that of the guide track 150 in that it has a narrow entrance portion and a wider recessed portion 149.

Accordingly, the guide member 140 is trapped within the guide track 148 to the extent that it can only travel back and forth from one end to the other, of the guide track 148. The drawing on the left shows the guide member 140 in the centre of the lateral guide track 148 and the drawing on the right shows the guide member at the left hand end of the lateral guide track 148. With the guide track 148 arranged across the width of a leg 112 or end of a side frame 116, the guide member 140 may travel in a track substantially parallel to the base frame 14. The heads of the studs at each end of the guide member 140 are preferably round to allow them to partially rotate within the track 148. This rotation allows the side frame to pivot with respect to the cot.

Although it would be possible to fit the double-headed stud or guide member 140 into the lateral guide track 148 in a similar manner to that of the guide track 150, i.e. by use of an access point 152, it is also possible that it and the associated guide track 148 are pre-assembled. This pre-assembly is indicated in broken lines and referenced 160 in Figure 8. This pre-assembly may be arranged on the side of the leg 112 or the end of the side frame 118.

Figure 9 is a view of an alternative means of allowing lateral movement between the side frame 116 and leg 112 (or end frame), while still retaining them together, in the form of a swivel assembly 165. This assembly comprises a guide member 140 rotatably fixed to an arm 145 by an inner stud 141. The guide member 140 is similar to that already described in relation to Figure 8. The other end of the arm is pivoted to the side frame 116 at point 143 such that the whole assembly may at least partially rotate about this point. In use, the guide member 140 is slidably retained in the guide path 150 such that the side frame 116 may slide up and down relative to the end frame or leg 112. However, the arm 145 and pivot point 143 allow the side frame 116 to pivot about the lower guide member 144 (refer to Figure 7) so that the guide pin 142 may travel along the curved portion of the upper guide path 150. It should be understood that the axes of rotation of the pivot point 143 and of the guide member 140 are substantially parallel. Further, the pivot point 143 is in a different, yet parallel, plane from the head of the guide member 140.

Figure 10 is a sequence of drawings showing how the side frame 116 is moved from a locked upper position to a lower position. The left hand view shows the former situation and the right hand view shows the latter situation. In the second view the side frame 116 is shown raised in direction "A". In the third view, the side frame 16 is shown tilted over in direction "B" (i.e. the upper portion has been laterally moved with respect to the end frames and the side frame has pivoted about the lower member 144). The guide pin 142 is thus permitted to travel around the curved upper portion of the guide track past the spring 156 and into the straight length of guide track 150, where it may travel down the length to the lower end thereof.

Another embodiment of the invention will now be described with reference to Figures 11 to 13, in which in Figure 11, a side view of a leg 212 is shown. On the surface of the leg a guide path, in the form of a channel 260, is provided. A cross-sectional view of the channel 260 is shown in Figure 12. It has a box-like shape with an opening 250 in thesurface 251 opposite the surface of the leg 212. The opening allows a shaft or neck 241 of a mushroom headed guide member 240 to pass such that the head of the member 240 is slidably retained in the channel 260.

The guide member 240 is fixed to the side frame 216. This arrangement allows a side frame 216 of a cot to slide relative to the end frames.

The channel is formed from a resilient material which may allow a degree of bending but which will substantially retain its shape once any applied force is removed. Such resilient material could be plastics, metal, or wood. Further, the channel 260 is fixed to the surface of the leg 212 by the use of screws 261 or other fixing means. However, the upper part of the channel 260 is not fixed to the leg 212. This allows the upper part of the channel 260 to be temporarily bent relative to the leg 212 and the remainder of the channel 260. In Figure 11, this bending is indicated by reference "B". Reference "A" shows the position of the unbent channel with no applied force. The reason for this bending will be discussed below with reference to Figure 13.

The upper part of the channel 260 is visible on the left of Figure 13. The channel in the unbent form is referenced "A" and in the bent form "B" in accordance with Figure 11.

Above the channel 260 a locking mechanism 269 is provided on the leg. The upper part of the channel 260 may bend within the arms 270,271 of the locking mechanism 269. However, these arms act to limit the bending or movement of the channel 260 as may be seen from the Figure.

On the right of Figure 13 there is a side view of an associated side frame 216. This side frame has a headless guide pin 242 and a mushroom (or flat) headed guide member 240. At least one further headed guide member, similar to the one referenced "240", is provided lower down the side frame 216 (not shown). The guide members 240 are similar to the ones described above with reference to Figures 4, 5 and 7 to 9. They allow the side frame 216 to slidably move relative to the end frame (or leg 212) but at the same time prevent the side frame from moving away from the end frame in a direction parallel to its length. Conversely, the guide pin 242 provides no assistance in retaining the frames together in this manner, although, if the pin was replaced by a headed member there is no reason why this could not occur.

As the side frame is moved relative to the end frames the pin 242 travels along the course of the guide slot 256 provided in the locking mechanism 269 and along the course of the channel 260 via the opening 250 (refer to Figure 12).

Only the shaft or neck 241 of the guide member 240 is shown in the drawing on the left of Figure 13 (shown as circles referenced "241") for the sake of clarity.

The head of the guide member 240 is slidably retained in the channel, as previously described, with the neck 241 protruding through the opening 250.

With the side frame 216 in the lower position (relative to the end frames) the channel 260 is unbent and the guide member 240 and guide pin 242 are both located in a portion of the channel lower than the portion shown in Figure 13.

As the side frame 216 is lifted, for instance by means of a user grasping and raising the upper rail 18, the guide pin 242 will exit the channel 260. Continued raising of the side frame 216 will force the pin 242 to travel along the guide slot 256.

However, as may be seen from the Figure, the guide slot 256 does not extend linearly upwards away from the end of the channel 260. Rather, the guide slot 256 bends first to the left and then back to the right before travelling downwardly and ending in a cul-de-sac 255. Accordingly, as the pin 242 is forced along the guide slot 256 the shaft 241 of the guide member 240 is forced to move laterally with respect to the leg or end frame. This occurs because the side frame 216 is slidably retained to the leg or end frame at at least two points by guide members 240.

Further, the guide member 240 in question is located immediately below the guide pin 242. The second guide member is located further down the side frame and it is about this lower guide member (similar to the one referenced "144" in Figure 7 for example) that the side frame pivots as the pin 242 travels along the guide slot 256.

The shaft 241 may move laterally with respect to the leg or end frame since the upper end of the channel 260 may bend, as described above. For instance when pin 242 is in position E, the shaft 241 is in position E'. Other positions of pin 242 are referenced C, D and F, with corresponding positions of the shaft 241 referenced C', D' and F', in Figure 13.

When the pin 242 is resting at the end of the cul-de-sac 255, the side frame 216 is in the upper position and is considered to be locked in place. This is because to unlock and lower the side frame 216 two actions have to be undertaken. These are the raising of the side frame 216, together with the lateral movement of the upper part of the side frame 216, relative to the end frames, while the side frame is raised.

As the side frame 216 is raised the pin 242 travels upwardly along the guide slot 256 from position C to position D. It then has to travel laterally to position E. Correspondingly, shaft 241 has to move from position C' to D' and then laterally to E'. The bending of the channel 260 allows this lateral movement. As the side frame 216 is lowered pin 242 then travels down to position F. The channel 260 will return to its unbent position by reason of its resilience so that the pin 242 then travels into, along and down the channel.

The resilience of the channel 260 also ensures that when the side frame 216 is raised the pin 242 is forced laterally from position E to position D so that the action of lifting to, and locking the side frame in, the fully raised position is easy to perform. Alternatively, or additionally, a biasing means (such as a spring) may be used to also ensure that the channel 260 returns to its unbent position ("A").

Although the embodiment described with relation to Figures 11 to 12 has the channel 260 located on the leg and the guide member 240 and pin 242 located on the side frame 216, this could be reversed. Furthermore, although the channel and locking mechanism 269 may be surface mounted they could also be recessed.

In the foregoing described embodiments the guide track has been illustrated and described as a channel in which guide members and pins may travel. It is also contemplated that the guide track could take the form of a rail around which the guide members are retained and may travel along, in a similar manner to well known curtain tracks and hooks. This type of rail could be pre-formed and surface mounted or counter-sunk in a channel in the frame or it could be shaped from the frame material itself.

Yet another embodiment of the invention will now be described with reference to Figure 14 and 15. This embodiment also requires two actions to unlock and lower the side fame 316 relative to the leg 312. Part of a side frame 316 of a cot is shown in Figure 14. The side frame 316 has an upper rail 318 and a lower rail 319.

Bars 311 extend between the upper and lower rails in a similar manner to that described with reference to Figure 1. One leg 312 of a cot is also shown on the left hand side of the side frame 316. A resilient straight rod 350 is provided and attached to the leg 312 at the top and bottom ends by fixing means 351,354.

However, the upper fixing means 354 allows the upper end of the rod to move laterally with respect to the leg 312 by virtue of a pocket provided therein. Further intermediate fixing means 325,353 are provided between the upper and lower fixing means 351,354. The rod 350 passes through these intermediate fixing means 352,353. The ends of the upper 318 and lower 319 rails are provided with holes through which the rod passes so that the side frame 316 may slide up and down relative to the leg 312 and yet be prevented from moving laterally away from the leg 312 in a direction parallel to the length of the side frame. The fixing means 352,353 are located so that the side frame 316 may be substantially lowered with respect to the leg 312. Finally, a locking mechanism 370 is provided on the leg 312 towards the top of the rod 350.

The rod is made of stainless steel but other materials are possible. The intermediate fixing means 353,354 may be selectively located so as to bias the rod 350 towards one side of the pocket in the upper fixing means 354. This may be achieved, for instance, by locating the upper intermediate fixing means 353 slightly off-set from an imaginary vertical line drawn upwardly from the bottom end of the rod 350. In Figure 15 the rod is biased towards the left.

Two side views of the leg 312 are shown in Figure 15. Also included in the views are the positions of the upper 318 and lower 319 rails of the side frame 316. The remainder of the side frame 316 has been omitted for the sake of clarity.

The locking mechanism 370 comprises a locking projection 371 on its upper side and a sloping surface 373 on one side. On the underside of the upper rail 318 a locking recess 372, corresponding to the locking projection 371, is provided.

To lock the side frame in the upper position it is raised by means of grasping the upper rail 318. As the upper rail 318 travels up the rod 350 it meets the locking mechanism 370 due to the rod 350 being biased towards the left hand side of the pocket in the upper fixing means 354. Continued lifting of the upper rail 318 forces the rod 350 to bend slightly to the right (as shown in the view on the right hand side of Figure 15) as the upper rail 318 is pushed in that direction by the sloping surface 373 of the locking mechanism 370. In this way the upper rail 318 may pass the locking mechanism 370 and continue its journey upwards. Once the upper rail 318 has passed the locking mechanism 370 the resilience of the rod 350 returns it to its previous left-biased position. When the user releases the upper rail 318 it will drop slightly until the locking recess 372 rests on the locking projection 371. The side frame 316 is thus considered to be in a locked position.

To lower the side frame 316 the user must first grasp and lift the upper rail 318.

However, the side frame 316 cannot be lowered until the rod is temporarily bent out of the way to the position shown in the right hand view in Figure 15. This is achieved by applying a lateral force to the upper rail 318 either in a direction towards or away from the cot. Once the upper rail 318 has passed underneath the locking mechanism 370 the lateral force can be removed. The side frame can thus be lowered relative to the end frames.

Claims

CLAIMS

1. A drop-side cot locking mechanism, for use with cots having a base frame, two end frames and two side frames, at least one of said side frames being slidable, relative to the two end frames, between upper and lower positions, the locking mechanism having means for releasably locking the slidable side frame in an upper position relative to the two end frames, the means being operable to release the slidable side frame from its upper position by lifting the slidable side frame, thereby to raise it relative to the end frames, and then by moving the upper part of the slidable side frame laterally, relative to the end frames, thus allowing the slidable side frame to be lowered.

2. A locking mechanism according to claim 1, including connecting means, the means comprising a first guide member, having engagement means, and a guide track, the engagement means being slidably retainable by the guide track, one of said guide track and said guide member being arrangeable on an end frame and the other of said guide track and said guide member being arrangeable on said slidable side frame, wherein a portion of the guide track is resiliently bendable, such that in use the connecting means slidably connects the side frame and end frame together allowing the side frame to move, relative to the end frame, in directions both parallel and perpendicular to its height, and to pivot about an axis parallel to its length, wherein the connecting means prevents the end frame moving away from the side frame in a direction parallel to the length of the side frame.

3. A locking mechanism according to claim 1, including connecting means, the means comprising a first guide member, having first and second engagement means, and first and second guide tracks, the first engagement means being slidably retainable by the first guide track, and the second engagement means being slidably retainable by the second guide track, one of said first and second guide tracks being arrangeable on an end frame and the other of said first and second guide tracks being arrangeable on the slidable side frame, such that in use the connecting means slidably connects the side frame and end frame together allowing the side frame to move, relative to the end frame, in directions both parallel and perpendicular to its height, and to pivot about an axis parallel to its length, wherein the connecting means prevents the end frame moving away from the side frame in a direction parallel to the length of the side frame.

4. A locking mechanism according to claim 3, wherein the first guide member is a shaft connecting and retaining a stud at each end.

5. A locking mechanism according to either one of claims 3 and 4, wherein either or both of the guide tracks are pre-formed channels or rails for either surface mounting on, or for being counter-sunk relative to, the relevant frame.

6. A locking mechanism according to claim 1, including connecting means, the means comprising an arm with at one end a first guide member having engagement means, and being pivotable about the other end, and a guide track, the engagement means being slidably retainable by the guide track, one of said arm and said guide track being arrangeable on an end frame and the other of said arm and said guide track being arrangeable on said slidable side frame, such that in use the connecting means slidably connects the side frame and end frame together allowing the side frame to move, relative to the end frame, in directions both parallel and perpendicular to its height, and to pivot about an axis parallel to its length, wherein the connecting means prevents the end frame moving away from the side frame in a direction parallel to the length of the side frame.

7. A locking mechanism according to any of claims 2 to 6, including two further guide members, each being arranged on either one of the side frame and end frame, for slidable engagement with a corresponding guide track.

8. A locking mechanism according to claim 7, wherein one of the further two guide members is a pin fixed to the relevant frame above the first guide member, and the other of the further two guide members is a stud, connected and retained on a shaft, fixed to the relevant frame below the first guide member.

9. A locking mechanism according to claim 1, including connecting means, the means comprising a guide member, having engagement means, and a guide rod, the engagement means being slidably retainable by the guide rod, one of said guide rod and said guide member being arrangeable on an end frame and the other of said guide rod and said guide member being arrangeable on said slidable side frame, wherein a portion of the guide rod is resiliently bendable, such that in use the connecting means slidably connects the side frame and end frame together allowing the side frame to move, relative to the end frame, in directions both parallel and perpendicular to its height, and to pivot about an axis parallel to its length, wherein the connecting means prevents the end frame moving away from the side frame in a direction parallel to the length of the side frame.

10. A locking mechanism according to claim 9, wherein the guide member is an upper rail of the side frame and the engagement means is a hole therethrough.

11. A cot comprising a base frame, two end frames and two side frames, wherein at least one side frame is slidable, relative to the two end frames, between upper and lower positions, the cot including a locking mechanism, according to any preceding claim, for releasably locking the slidable side frame in an upper position.

12. A cot according to claim 11, wherein the frames are constructed predominantly of wood.

13. A method of releasing and moving a slidable side frame of a drop-side cot from a locked upper position to a lower position, wherein the cot has a base frame, two end frames, and the said side frame, and wherein the said side frame is slidable relative to the two end frames, the method comprising the steps of: a) lifting the side frame to raise it relative to the end frames of the cot; b) moving the upper part of the slidable side frame laterally relative to the end frames; and c) lowering the side frame relative to the end frames.

14. A drop-side cot locking mechanism substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.

15. A cot including a locking mechanism substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.