EP1378220B1

EP1378220B1 - Stretcher retention

Info

Publication number: EP1378220B1
Application number: EP03252730A
Authority: EP
Inventors: Shahid Saleem; Robert Williamson; David Paul Whyman
Original assignee: Ferno UK Ltd
Current assignee: Ferno UK Ltd
Priority date: 2002-06-27
Filing date: 2003-04-30
Publication date: 2008-10-15
Anticipated expiration: 2023-04-30
Also published as: DE60324063D1; ATE410987T1; EP1378220A1; GB0214812D0

Abstract

A collapsed stretcher (30) is moved on to an ambulance floor. A restriction loop 20 directly secured to the front of the upper frame 29 passes beneath guide rails 15 as the stretcher is being loaded into the ambulance to correctly align the front of the stretcher and, when fully loaded, to directly retain the front of the upper frame against sideways movement and upwards movement. When fully loaded, fixed rearwardly facing catches 52 partly surround a bar 31 secured to the upper frame 29 with movable catches 53 also partially surrounding the bar 31 to retain the rear of the upper frame against upwards or downwards movement, sideways movement and fore and aft movement. <IMAGE>

Description

The present invention relates to a stretcher and stretcher securing arrangement.
When stretchers are located inside ambulances it is necessary that they are retained securely in case the ambulance is subject to sudden braking or in case the ambulance is involved in a crash. If the ambulance is involved in a crash the stretcher should not be loose within the ambulance. Accordingly, it has been known to secure the lower frame of a stretcher, on which a patient is supported on an upper frame. Should the ambulance crash the anchors retain the lower frame in position. However, in extreme circumstances the upper frame is liable to bend or the cross members connecting the upper and lower frames may break resulting in injury of the patient strapped to the upper frame and possibly also to attendants within the ambulance. This type of injury may well be of a very serious nature if the patient being transported has spinal injuries which require the back to be kept straight.
EP 0 821 927 and US 5 092 722 disclose an ambulance mounting arrangement comprising a single longitudinal guide track. These are able to hold down parts of the stretcher at the centre of the stretcher.
GB 2 203 999 discloses a platform 10 that is moveable relative to the floor of an ambulance that receives a stretcher. The front of the stretcher is retained by a central hook 36.
US 5 779 296 relates to a helicopter transport arrangement in which a stretcher is attached to a moveable platform.
US 5 494 386 discloses a stretcher with movement limiting members located along the side of the stretcher.
US 5 205 601 relates to a stretcher that does not have an upper and lower frame moveable relative to each other.
It is an object of the present invention to attempt to overcome at least some of the above or other disadvantages.
The present invention is defined in the claims and elsewhere in this specification.
The retention means may be arranged to act at a location intermediate the ends of the stretcher.
The retention means may be arranged to act directly on each of a pair of side members of the upper frame.
The retention means may be arranged to act at a location on the upper frame substantially midway between the ends of the stretcher.
The retention means may be arranged to resist relative movement of the stretcher upwardly with respect to the vehicle. Alternatively or additionally the retention means may be arranged to resist relative movement of the stretcher forwardly or rearwardly relative to the vehicle or both or relative sideways movement to one side or to the other side or both or any combination thereof.
The retention means may be arranged to be automatically engaged upon loading of the stretcher into a vehicle.
The upper frame may be movable relative to the lower frame between a raised and a lowered position.
The retention means may include at least one member secured to the upper frame of a stretcher and extending downwardly to engage apparatus secured to the floor of a vehicle. The member may extend downwardly, beneath the level of the lower frame, for instance when the upper frame is in the lowered position. The retention means may be secured to the vehicle floor and may extend to a lower elevation than the lowermost part of the lower frame at the forward end of the stretcher and may be of less width than the distance between two wheels at the front region of a stretcher. The member may extend downwardly, beneath the level of the lower frame and may extend inwardly of outer side member of the lower frame. The member may include an enlarged lower portion arranged to be located beneath a downwardly facing surface of a member secured to the vehicle floor.
The retention means may include one part, fixed and immovable on the stretcher, such as the upper frame of the stretcher being arranged to cooperate with another part fixed and immovable on the vehicle.
The retention means may include two retainment members secured to the upper frame of a stretcher substantially towards each end of said upper frame extending downwardly to engage apparatus secured to the floor of a vehicle substantially towards each end of said upper frame. The members may extend downwardly, beneath the level of the lower frame. The members may extend beneath the level of the lower frame when the upper frame is in the lowered position.
At least one retainment means may include a first retainment member extending downwardly through the lower frame substantially towards one end of said lower frame. Those means may also include a second retainment member extending downwardly from a position on the upper frame substantially towards one end of said upper frame to a position adjacent to the lower frame. The first and second members may comprise two spaced downwardly extending bars secured to the upper frame connected by a transverse bar at a location remote from the upper frame.
At least one holding or retention means such as an end region holding means may be secured to a vehicle floor, such as substantially towards one end of a stretcher retainment position, such that once a stretcher is in the retainment position at least one retainment member such as the transverse bar may be held in place. The holding means may include at least one clamp which may secure at least one retainment member to a vehicle floor. The clamp may be movable between a release and a holding position and may be operable by an operator. Said clamp may be operable by the foot of an operator or by an actuator. Alternatively, the clamp may be operable by abutment of part of the stretcher with an actuator upon movement of the stretcher into the vehicle. Said clamp may be arranged to be in a holding position unless operated by an operator. The holding means may include a further clamp which may be fixed relative to the vehicle floor. The further clamp may be arranged to partially surround a member secured to the upper frame when the stretcher is in the retainment position. When the further clamp and the other clamp which is in the closed position engage a retainment member secured to the upper frame they may act to resist movement of that portion of the upper frame in one, two, three, four, five or six relative directions such as to one side or the other side or both, or forwardly or rearwardly or both or upwardly or downwardly or both or any combination thereof.
The securing arrangement may include a second end region holding means arranged to resist relative movement of an end region of the upper frame in at least one or two or three or four or only four relative directions such as rearwards movement, upwards movement, movement to one side or movement to the other side or any combination thereof.
The second holding means may be secured to a vehicle floor towards one end of a stretcher retainment position such that once a stretcher is in said retainment position at least one retainment member secured to the upper frame of the stretcher may be held in place.
The second holding means may include guide means arranged to cooperate with at least one retainment member secured to the upper frame to guide an end region of the stretcher into a retainment position. The guide means may diverge such that the retainment member may slide past the guide means and may continue until a point where said retainment member abuts said guide means and is unable to move further. The retainment member may be arranged to abut the guide means with such abutment being arranged to cause the sideways movement of at least a part of the stretcher upon pushing of the vehicle forwardly into the vehicle. The second holding means may also be arranged, in use, to abut a portion secured to the floor of a vehicle to restrict relative movement of at least part of the stretcher upwardly relative to the floor of the vehicle.
The retention means may include a snap fitting arranged to be actuated upon relative movement of the stretcher into a vehicle to effect the retention. The snap fitting may include a release member arranged to release the snap fitting. The retention means may include two spaced snap fittings.
The securing arrangement may include front holding means arranged to resist relative movement of the front of the stretcher with respect to a vehicle in at least one, and preferably two, three or four relative directions such as to one side or to the other side or forwardly or upwardly or any combination thereof.
The securing arrangement may include rear holding means arranged to resist relative movement of the rear of the stretcher in at least one or two or three or four relative directions such as rearwards movement, upwards movement, movement to one side or movement to the other side or any combination thereof.
The arrangement may include a first clamp secured to the vehicle arranged to at least partially surround a part of a stretcher to assist in retaining the stretcher in position in the vehicle, the first clamp being movable from a first position in which the stretcher can enter and leave the vehicle and a second position in which a part of the stretcher is retained in position.
The clamp may retain an end region of the stretcher. The clamp may be pivotally movable between the first and second positions such as about an axis extending transverse to the direction of movement of the stretcher into the vehicle which axis may extend in the same general direction as the general plane of the floor of the vehicle. The clamp may be arranged to be in the second position until it is caused to be moved to a first position, for instance by an operator such as the foot of an operator or by an actuator or automatically such as by movement of the trolley into the vehicle.
The clamp may be arranged to be acted on by a clamp operating member arranged to move from a first position in which the clamp is able to be in the first position and a second position in which the clamp is caused to be in the second position. The member may be arranged to be located between a part fast with the floor of the vehicle and the clamp when in the second position.
The arrangement means may include a second clamp arranged to at least partially surround a part of the stretcher such as a cross-member. The second clamp may be fixed in position. The second clamp may be arranged to be engaged by part of the stretcher upon movement of the stretcher into the vehicle. The second clamp may be arranged to at least partially surround the same member as the first clamp. The first and second clamps may be staggered from each other in a direction transverse to the direction of movement of a stretcher into and out of the vehicle. There may be at least two first clamps or second clamps or both. Each of the first clamps or second clamps or both may be staggered from each other with respect to the direction of movement of a stretcher into the vehicle.
The part of the stretcher that is surrounded by the clamp may comprise a part secured to an upper frame of the stretcher.
At least one clamp may be arranged to abut a part of the stretcher to resist sideways movement in at least one direction when in the second position.
The present invention can be carried into practice in various ways but several embodiments will now be described, by way of example, with reference to the accompanying drawings, in which:-

Figure 1 is schematic view of front guide and securing member attached to an ambulance floor;
Figure 2 is schematic view of the front guide and securing member interacting with a restriction loop attached to an upper frame of a stretcher;
Figure 3 is schematic perspective view of a stretcher showing the direction of movement that is effected to connect the stretcher to the front guide and securing member;
Figure 4 is a perspective view of a rear retaining box;
Figure 5 is a schematic front view of a rear retaining box;
Figure 6 is a schematic plan view of a rear retaining box;
Figure 7 is a schematic perspective view of a stretcher showing a rear retainment bar secured to an upper frame of the stretcher which, in use, will be secured by a rear retaining box such that the upper frame of the stretcher is directly secured to the ambulance floor;
Figure 8 is a schematic perspective view of a stretcher showing the stretcher in a lowered position with an upper frame being secured to an ambulance floor via front and rear retainment means;
Figure 9 is a schematic plan view of a rear retaining box when moveable rear catches are in an unengaged position;
Figure 10 is a schematic front view of a rear retaining box when moveable rear catches are in an unengaged position;
Figure 11 is a schematic plan view of an ambulance floor 10;
Figures 12 and 13 are a plan and a side view of an antler mounting 12 used to secure the front of the stretcher;
Figures 14 and 15 are a deactivated and an activated schematic view of a rear ratchet clamp 114;
Figure 16 is a schematic perspective view of a stretcher showing the direction of movement that is effected to connect the stretcher to the rear ratchet clamp 114 and a mid retaining box 116;
Figure 17 is a side perspective view of a stretcher trolley showing how upper and lower frames 118 and 120 are moved relative to each other;
Figure 18 is a perspective view of a bracket 122 that is secured to the upper frame of a stretcher in order that the upper frame can be secured to the mid retaining box;
Figure 19 is a first perspective view of the mid retaining box 116;
Figure 20 is a perspective view showing the bracket 122 secured to the retaining box 116 with the rear of the stretcher being secured to the rear ratchet clamp 114;
Figure 21 is a perspective view showing the operative parts of the retaining box 116, and
Figures 22 and 23 are schematic plan and end views of the latching mechanism of the retaining box 116 in the open position.

Referring to Figure 1 a preferred front guide and retainment member 10 is shown. The front guide and retainment member comprises a base plate 12, an inverted U-frame 13, support members 14 and guide rails 15 that converge in a rearwards direction to meet at a point 16.
In use the guide and retainment member 10 is secured to the floor 11 of an ambulance.
Figures 3, 7 and 8 show a stretcher 30 modified to comprise a restriction loop 20 secured to an upper frame member 21. The restriction loop 20 is secured to the upper frame towards the front of the stretcher via attachment to a cross member 21 on the upper frame. This is shown in Figure 8. Figures 3 and 8 also show a rear retainment bar 31 secured to the upper frame of the stretcher 30 towards the rear of said stretcher. This will be described in more detail later.
In use, with the upper frame 29 having been lowered towards the lower frame 35, the restriction loop 20 will secure the front of the upper frame 29 of the stretcher directly to the floor of an ambulance by its interaction with the front guide and the retainment member 10. This interaction can be seen in Figure 2. With the stretcher in the lowered position, the restriction loop 20 will be at a height above the floor of the ambulance that will allow it to pass over the guide rails 15 of front guide and the retainment member 10. Once restriction loop 20 has engaged the retainment member 10 the stretcher will be unable to move in a forwards or upwards direction or in a sideways direction. Motion is prevented by the v-shape of guide rails 15 which, upon forwards movement of the stretcher, enter the loop 20 and cause any misalignment of the front of the stretcher to be connected by bearing against one side or the other of the loop. Once the restriction loop is at a point where the width of the loop is equal to the distance apart of the guide members 15 the restriction loop 20 will be unable to travel any further along the guide members 15. Motion of the stretcher is also prevented in an upwards direction by the abutment of lower cross member 22 of the restriction loop 20 with the underside of the guide rails 15. As a result in the event of a crash the front portion of an upper frame will resist motion in a forwards or vertical direction and in a side to side direction and hence will retain the stretcher in position in the ambulance.
The support members 14 strengthen the frame 13 on which guide members 15 are supported such that in the event of a crash, the frame 13 will resist motion in a horizontal or vertical direction and hence retain the stretcher in position in the ambulance.
Figures 4, 5 and 6 show a preferred rear retaining box 50 comprising a raised base plate 51, two fixed rearwardly facing clamps or catches 52, two moveable clamps or catches 53, and a catch engaging element 54. Also shown in Figure 4 is the rear retainment bar 31 which is connected to the upper frame of the stretcher. In use the rear retaining box 50 is secured to the floor of an ambulance.
The moveable rear catches 53 are hinged about a horizontal bar 57 onto which they are attached at points 56. When the system is not in a locked position the moveable catches 53 will be in an unengaged position as shown in Figures 9 and 10. These Figures show that when the catches 53 are in the unengaged position, they are at a substantially lower position than when they are in locked position. To move the catches 53 from their lower unengaged position to their raised locked position, a catch engaging element 54 is moved from position 55 (shown by the broken lines in Figure 4) rearwardly to that as shown. As the catch engaging element moves from position 55 it will engage the rear of the catches 53 and upon further motion of the element 54, the catches 53 pivot about points 56 and raise up in an anti-clockwise direction onto the element 54, raising into their engaged position.
When the catches 53 are raised into the locked position as shown in Figure 4, the retainment bar 31 is locked in place and cannot move in either a horizontal or a side to side (by abutment with the side supports or the retainment bar) or vertical direction. As a result in the event of a crash the rear portion of the upper frame will resist motion and hence retain the stretcher in position in the ambulance.
The preferred embodiment of the present invention provides a foot pedal 57 connected to the engaging element 54 by a shank 56. The element 54 maintains a rest position such that the catches 53 are always in the locked position. An operator must push the pedal 57 inwardly to move the engagement member 54 to the unengaged position 55. Upon depression of the pedal 57, the shank 56, which is hinged to a top part of the pedal at one end and to engaging element 54 at the other, is moved in the direction shown by the arrow 59. As a result engaging element 54 is also moved in direction 59 towards the position 55. When the element 54 no longer engages the catches 53 they drop to their lower unengaged position exposing the catches 52, and allowing insertion of retainment bar 31.
When retainment bar 31 is in place, the operator releases the pedal 57 and a spring mechanism (not shown) returns the engaging element 54 back to its locked position, locking retainment bar 31 and in place as previously described.
This system whereby the stretcher retainment mechanism is always locked and requires unlocking before loading of a stretcher can be achieved is a safety feature of the present invention. That is because an operator is always required to unlock the system before loading a stretcher and the system always returns to the locked position after the stretcher is loaded. This allows for the rear retainment means never to be overlooked in the heat of the moment. Once a stretcher is loaded it will automatically be locked in position.
In the lowered position of the upper and lower frames, the restriction loop 20 and the retainment bar 311 are moved to extend beneath the lower frame.
Removal of the stretcher is achieved by pushing the pedal into the ambulance to release the catches and then pushing the trolley out.
Alternatively, a powered means for moving the engaging element 54 may be provided. An actuator may be provided (not shown) such that the movement of the engagement member to position 55 may be achieved without physical exertion of the operator. The operation may be conveniently activated by depressing a button located within the ambulance.
A method of loading a modified stretcher will now be described with reference to Figures 3, 4, 6 and 8.
When a stretcher operator places a stretcher 30 into an ambulance, the stretcher, in its lowered position, is pushed from the in a direction as shown by arrow 32 in Figure 3. The restriction loop 20 will engage the guide and retainment member 10. The v-shape of guide members 15 automatically guides the stretcher into the correct position as it is pushed further into the ambulance until both sides of loop 20 fully abut the guide members 15, and hence the stretcher 30 cannot be moved any further forward.
The retaining box 50 and the guide and retainment member 10 are distanced apart from each other on the ambulance floor such that when restriction loop 20 fully engages the rear guide and retainment member 10, the front retainment bar is stopped by the catches 52.
The height above the floor of the ambulance of the retaining bar 51, when the stretcher is in its lowered position, is matched by the height above the ambulance floor of the two forward facing catches 52.
Once the restriction loop 20 abuts the guide members 15 the trolley will be in the correct retainment position within the ambulance and the retainment bar 31 will be abutting the forward facing catches 52 such that the retention of the rear of the stretcher may be achieved by closing moveable rear catches 53. Once the rear catches are closed the stretcher will be fully retained in the ambulance, it will be unable to move either horizontally or vertically.
In an alternative embodiment (not shown) the movement of the trolley into the ambulance may cause the element 54 to move to the position shown at 55 to clear the way for the bar 31 to move into the catches 52. When, or just before the bar 31 is fully home, the abutment on the trolley need no longer act on the element 54 allowing the element to spring back to allow the catches 53 to capture the bar 31. That disengagement of the trolley with the element 54 may be by way of the element 54 moving rearwardly and to one side under the force of engagement with the trolley with that sideways movement passing a certain extent such that the abutment on the trolley no longer acts to push the element against its spring loading.
As shown in Figure 11, a stretcher is collapsed and moved onto the ambulance floor in the direction of arrow 124. The front of the lower frame of the stretcher is secured by the antlers 112 and the rear of the lower frame of the stretcher is secured by the ratchet clamp 114. Securement by the antlers 112 and the ratchet clamp 114 of the lower part of a stretcher is known. In the position shown, the stretcher is located over a wheel hub 126 that projects up into the ambulance. The front of the stretcher is guided by the antlers such that the forward wheel mountings 28 are located beneath the antlers with a tube 130 extending above those wheel mountings 128 being located in arcuate recesses 132 of the antlers. Abutment of the tubes 30 with the recesses 132 resists relative forward movement of the stretcher in the ambulance and abutment of the wheel mountings 128 with the underside of the antlers resists upwards movement of the lower part of the frame. The recesses 132 are located above the floor 110 of the ambulance by appropriate supporting framework 134 that extends down and is secured to the floor 110. The arcuate recesses 132 are formed by rearwardly and outwardly diverging sections 136 that ensure that the tubes and therefore the stretcher is guided into the correct position.
As seen in Figure 16, the lower frame of the stretcher includes a cross bar 138. A pair of brackets 140 extend downwardly from the cross bar 138 with an axle 142 extending between the lower portions of the brackets 140. In the operative position, the ratchet clamp 114 is in the position shown in Figure 15 in which two hooks 144 extend over the axle 142 with downwardly extending bars 146 of the clamp resting against the rearwardly facing portion of the axle 142. The rear ratchet clamp resists upwards movement of the lower frame at the rear of the stretcher by abutment of the axle 142 with the hooks 144 and rearwards movement of the lower frame of the stretcher by abutment of the axle 142 with the bars 146.
In order to release the ratchet clamp 114 from the position shown in Figure 15 to the position shown in Figure 14, in which the hooks 144 and the bars 146 lie against the floor, an operative engages sprung members 148 with each hand to cause spigot pins 150 attached to the sprung members to be raised from the position shown in Figure 15 to allow them to clear openings (not shown) in rods 152 such that cylinders 154 can slide rearwardly on the rods 152 towards an end stop 156 with pivotal movement of the cylinders 154 about the rods 152 being able to occur when the hooks 144 are clear of the axle such that the clamp is in the position shown in Figure 14. In order to attach the ratchet clamp to the lower frame, the hooks and bars 144 and 146 are pivoted upwardly from the position shown in Figure 14 and then slid along the rods 152 until the axial is engaged and the spigot pins 150 automatically snap into the openings in the rods 152 to hold the bracket in position.
Thus, with the rear ratchet clamp 114 and the antlers 112, the front and rear of the lower frame of the stretcher are held in position. However, what is desired by that holding is of course the retention of the upper frame in position and that is not directly achieved with either the antlers or the ratchet clamp.
In this respect, Figure 17 illustrates the form of stretcher that it is intended to use the apparatus with and it comprises the upper frame 118 and the lower frame 120. In Figure 17, these frames are shown spaced apart. However, the frames are able to move towards and away from each other as they are connected by a first pair of spaced, parallel linkages 158 and a second pair of cross linkages 160 that are also parallel with each other. The upper and lower end of each linkage 158 is pivotally connected, respectively, to the upper and lower frames 118 and 20 with adjacent linkages 158 and 160 from each pair being pivotally connected at point 162. Some movement of the rear pivot connections of the upper and lower members of each linkage in the extent of the general plane of the upper and lower frames is permitted to allow for the raising and lowering of the upper and lower frames relative to each other. Latches (not shown) are provided, or other control means may be provided to allow the frames to remain in their respective positions. In the position in which the stretcher is anchored into the ambulance, the upper frame has been lowered and rests and is located on upwardly extending bars 164 from each tube 130 with the pin 178 having been lowered past the lower frame. For convenience, the connecting linkages are not shown in Figure 16.
As shown in Figures 16 and 18, the bracket 122 is secured approximately midway along spaced side members 166 of the upper frame with the side members passing through and being secured to channels 168 formed in the bracket. A central cross bar 170 extends between and connects downwardly and inwardly extending bars 172 that are connected to each channel 168 and downwardly extending bars 174 extend vertically from the bar 172 in order that they clear and extend beneath the lower frame 120 when the frames are collapsed towards each other, as shown. At the bottom end of each bar 174 brackets 176 extend inwardly towards each other with a pin 178 extending down from each bracket 176 with the pin having an enlarged head portion 180. In the position shown in Figure 20, the pins 178 abut a portion of the retaining box 116 to prevent relative forwards or rearwards or side to side movement of the upper frame of the stretcher with respect to the ambulance and with the heads 180 abutting a portion of the retaining box 116 to prevent relative upwards movement. The manner in which this is achieved will now be described.
In the position shown in Figure 21, slam latches 182 are in the closed position in which the pins 178 will extend through and be retained in their openings 184. To release the pins a lever 186 is moved forwardly to cause its rotation about a fixed pivot 188 which in turn causes a link 90 to move rearwardly. That movement of the link 190 causes links 192 that are pivotally connected to the link 190 to move about fixed pivots 194 to release the slam latches 182.
As shown in Figure 19, the box 116 includes rearwardly and outwardly diverging channels 196 that ensure that the pins 178 are guided precisely into the awaiting open slam latches. The position of the open slam latches is shown in Figures 22 and 23.
A U-shaped bracket 198 includes three pivot pins 200,202,204 extending therethrough on which are respectively mounted first and second retaining plates 206 and 208 and a latch plate 210. Respective springs 112,114 and 216 bias the retention plate 206 in a clockwise direction, the retention plate 208 in an anti-clockwise direction and the latch plate 210 in a clockwise direction.
As a pin 178 of the bracket 122 abuts the camming surface 218 of the plate 208, that plate is urged against its spring bias in a clockwise direction with a curved surface 220 of the plate 208 pushing a cooperating surface 222 of the plate 206 in an anti-clockwise direction until the pin is retained in an enclosure defined by an arcuate surface 224 on the plate 208 and the almost abutting surfaces 226 of the plate 208 and the face 228 of the plate 206.
As the closing motion of the plate 208 occurs, a camming surface 230 of that plate urges the latch plate 210 in an anti-clockwise direction with a latch point 232 of the plate 210 resting first in a notch 234 and then in a notch 236 of the plate 108 to hold the parts in the closed position.
When the release lever 186 is actuated, the latch plate 110 is caused to move in an anti-clockwise direction to urge the latch point 232 out of engagement with the notches to cause the plates 206 and 210 to spring back to the position shown.
The space indicated as 238 is the region where, in use, the enlarged head of the pin 178 will be located.
Accordingly, it can be seen that the upper frame at an intermediate section from the ends, and generally in the middle section, is directly retained against forwards movement, rearwards movement, side to side movement and also rearwards movement and up and down movement with respect to the ambulance floor thus affording an extremely safe anchoring system for a stretcher in the ambulance.
The present invention allows the stretcher to pass very stringent safety tests. These safety tests involve 10 g impacts in six directions, those of forwards, backwards, from both sides and upwards and downwards. A 10 g impact is equivalent to an ambulance travelling at 40 miles per hour impacting with a solid immovable wall.

Claims

A stretcher (30) and stretcher securing arrangement, the stretcher including an upper frame (29) and a lower frame (35), the securing arrangement including forward (10) and rearward (50) retention means arranged to act at both forward (20) and rearward (31) end regions respectively of the upper frame (22) whereby the upper frame is directly retained in at least one direction of relative movement, characterised in that the movement of the stretcher into a vehicle causes the forward end region (20) to be guided towards the forward retention means in a sideways direction by the forwards retention means (10).
A stretcher and stretcher securing arrangement as claimed in Claim 1 in which the forwards retention means is arranged to be secured to a vehicle floor and to extend to a lower elevation than the lowermost part of the lower frame at the forward end of the stretcher.
A stretcher and stretcher securing arrangement as claimed in Claim 1 or 2 in which the stretcher comprises two wheels at the front of the stretcher and the forward retention means is of less width than the distance between said two wheels.
A stretcher and stretcher securing arrangement as claimed in Claim 3 in which the forward retention means include guide rails (15) that converge in a rearwards direction to meet at a point (16).
A stretcher and stretcher securing arrangement as claimed in any preceding claim in which the forward end region includes at least one member secured to the upper frame arranged to extend downwardly and, in the lowered position, below the level of the lower frame to engage the forward retention means.
A stretcher and stretcher securing arrangement as claimed in Claim 5 in which the member extends inwardly of the outer side member of the lower frame.
A stretcher and stretcher securing arrangement as claimed in Claim 5 or 6 in which the member includes a lower portion arranged to be located beneath a downwardly facing surface of the forward retention means.
A stretcher and stretcher securing arrangement as claimed in any preceding claim in which the upper frame is movable relative to the lower frame between a raised and a lowered position such that, upon movement of the upper frame from the raised to the lowered position at least one portion at the forward end region of the upper frame and secured to the upper frame is arranged to move from a position in which that portion is above the lower frame to a position in which that portion is at a lower elevation than the lower frame.
A stretcher and stretcher securing arrangement as claimed in any preceding claim in which at least one retention means is arranged to be automatically engaged upon loading of a stretcher into a vehicle.
A stretcher and stretcher securing arrangement as claimed in any preceding claim in which the retention means includes a retainment member (31; 178) on the stretcher arranged to be secured to the vehicle floor by at least one clamp (52, 53; 206, 218).
A stretcher and stretcher securing arrangement as claimed in Claim 10 in which the clamp (53) is movable between a release and a holding position and which includes a further clamp (52) fixed relative to the floor of a vehicle, the two clamps being arranged to cooperate with the retainment member of the retention means when the upper frame is directly secured to a vehicle floor.