Roll-in cot

0001The present invention relates to emergency cots, such as of the type used to transport patients. In particular, the present invention relates to roll-in cots having collapsible legs, of the type used in emergency vehicles such as ambulances.

0002Emergency cots of the roll-in type are used to support a patient on a stretcher, the stretcher being mounted on a wheeled undercarriage or transporter. A patient may be manoeuvred on an emergency cot by a single operator at the trailing end or maybe manoeuvred with the assistance of other operators on the wheeled transporter.

0003Emergency cots of the roll-in type are configured to be able to be rolled into various types of rescue vehicles, such as ambulances, vans, station wagons, modular type rescue vehicles, aircrafts, helicopters and the like. In order to be able to roll an emergency cot into such a vehicle, the cot generally is configured to support the stretcher at a similar height to that of the platform in the emergency vehicle upon which the patient is to be transported. The undercarriage or transporter collapses to be beneath the stretcher and is supported on the platform.

0004During the loading of a patient onto a platform in an emergency vehicle the wheel transporter or undercarriage needs to be collapsed. As the wheeled transporter collapses, the operator is required to support the weight of the patient and the emergency cot and push the emergency cot onto the platform. In order to facilitate the loading of a patient onto such a platform, the wheeled trolley generally loading rollers at its leading end that are positioned at the height of the platform such that the loading wheels engage the platform prior to the collapse of the wheeled trolley. Thus the leading end of the emergency cot is supported on the platform and the operator supports the rear of the emergency cot.

0005Once the leading end of the emergency cot is supported on the platform, the operator will typically activate a handle causing part or all of the wheeled transporter to collapse. Typically, the wheeled transporter will have leading collapsible legs and trailing collapsible legs in many configurations of emergency cots. Both the leading and trailing collapsible legs are generally operated by a single handle and the operator is required to support the rear of the emergency cot for a substantial period during loading. In other configurations, separate handles have been provided for the leading collapsible legs and the trailing collapsible legs respectively. The provision of separate handles for operation of the leading and trailing collapsible legs respectively allows the leading collapsible legs to be activated initially and the emergency cot pushed further onto the platform and be supported on wheels attached to the leading legs at an intermediate position prior to the collapse of the trailing collapsible legs. In this manner, the operator is required to support a lesser weight as more of the weight of the cot and patient is supported on the platform and the moment of force is also reduced. The moment of force depends on whether the stretcher is fitted with additional sets of wheels near the centre of the stretcher such as on the collapsed, folded back loading legs. On a stretcher with only loading wheels that engage the platform the moment stays the same because the distance between the loading wheels and the operator is the same no matter how far the stretcher is moved into the vehicle. Irrespective of the weight borne by the operator, the length of time the operator has to bear the weight is reduced if the trailing wheels are collapsed at the last possible time. However, the added complexity in operating the respective handles in sequence during the loading of a patient into an emergency vehicle is often cumbersome and may result in the respective handles being operated out of sequence thereby causing the operator to have to unexpectedly support the weight of the patient and the emergency cot. <patcit id="pcit0001" dnum="US2877047A"><text>US 2877047</text></patcit> describes a cart having a latch which nods the under carriage in an elevated or upright position and a latch operator which engages the vehicle as the cart is advanced into the vehicle and releases the latch to permit the under-carriage to collapse.

0006We have now found an emergency cot that enables simplified operation of the respective leading and trailing collapsible legs in the desired sequence or which overcomes or ameliorates one or more of the disadvantages described above, or which at least provides the consumer with a useful or commercial choice.

0007In the present invention there is provided a roll-in cot having a patient support attached to a wheeled transporter, the wheeled transporter comprising leading and trailing collapsible legs having respective proximal ends pivotally connected to a frame and distal ends including wheels, wherein the leading collapsible legs are operable from a locked condition by a release assembly, the release assembly comprising a safety and a leg release wherein one of said safety and said leg release comprises a linkage, which in an activated condition prevents the collapse of the leading collapsible legs, said linkage being connected to a touch bar disposed in front of said leading collapsible legs whereby engagement of the touch bar characterised in that deactivating either the leg deactivates the linkage and enables the collapsible legs to be collapsed release or the sately without the other will not cause leading legs to collapse.

0008The patient support used in the roll-in cot of the present invention may be in any convenient form. Suitably, the patient support may be in the form of a stretcher. However, it will be appreciated that other patient support configurations may be used such as chairs or the like. It is preferred that the patient support be in the form of a segmented stretcher whereby respective segments may be contoured to provide improved support for the patient.

0009The patient support may be removably attached to the wheeled transporter. The patient support may be a detachable stretcher that may be reversibly attached to the frame of the wheeled transporter. However, it is within the scope of the present invention for the patient support to be permanently affixed to the wheeled transporter.

0010The wheeled transporter includes a frame on which the patient support is mounted and to which the leading and trailing collapsible legs are pivotally connected. The frame may be of any convenient configuration and may preferably be adjustable in height such that the roll-in cot may be readily loaded into an emergency vehicle. The frame may also include provision for the attachment of medical appliances thereto that may be associated with patient transport. For example, the frame may include a receptacle for holding an oxygen cylinder or heart monitoring equipment.

0011The leading and trailing collapsible legs are typically each in the form of a pair of legs, one by on either side of the frame so as to provide stability to the loaded cot. Preferably, a pair of leading legs will be spaced apart by a greater or lesser distance than a trailing pair of legs such that in a collapsed state the respective pairs of legs can collapse into a nested configuration.

0012An alternative configuration employs a single leading leg and/or a single trailing leg, each spaced apart wheels at the distal ends thereof. In order to further explain the present invention the cot will be described with reference to a cot having pairs of leading and trailing collapsible legs and it will be appreciated that the invention embrace cots with other leg configurations.

0013Whilst it is within the scope of the present application that the collapsible legs fold in a forward direction, it is preferred that the legs fold rearwardly whereby they are urged in a rearward direction by the relative movement of the cot relative to the platform.

0014The leading and trailing collapsible legs are pivotally connected to the frame. It is preferred that the respective pairs of collapsible legs be connected to the frame through a hinge that extends the width of the frame and through the proximal end of the respective pairs of collapsible legs. It is preferred that the respective pairs of collapsible legs be provided with bracing members that extend there between to stabilise the respective pairs of collapsible legs. The respective pairs of collapsible legs may be splayed, i.e. that the leading pair of collapsible legs be angled forward and the trailing pair of collapsible legs be angled backwards. A strut may extend from the respective pairs of collapsible legs, which strut may engage the frame thereby retaining the collapsible legs in a locked condition. Vertical legs may also be used. At the distal end of the collapsible legs wheels are provided so as to enable the roll-in cot to be readily manoeuvred by a single operator. The wheels may be rotatably mounted on the distal ends of the collapsible legs so as to form casters or the like. Rotatably mounted wheels may be selectively locked, preferably in line with the roll-in cot so that the roll-in cot may be pushed in a straight line.

0015In the locked condition, the pairs of legs are retained in an erect condition and by either deactivating the leg release or the safety will not cause the legs to collapse.

0016In one embodiment, the leg release and the safety both independently retain a pair of legs in and erect condition and thus the deactivation of either is insufficient to collapse the legs.

0017Both the leading and trailing pairs of collapsible legs include a release assembly for initiating the collapse of the respective pairs of legs. The mechanisms may be independent, or integrated to a greater or lesser extent.

0018The linkage may be in the form of a pawl and stop, in the form of a pin-in-slot, incorporate a detent, lug, tab, hook or other similar means that directly or indirectly retains the legs in an erect state whilst the linkage is in an activated condition.

0019The release assembly comprises a leg release and also includes a safety whereby operation of both the safety and the leg release are required to collapse the legs of the cot. In the content of the present invention where a touch bar is used, the presence of a leg release and a safety prevents the inadvertent collapse of wheels due to an accidental knock to the touch bar.

0020The release assembly comprising a leg release and a safety may on one embodiment comprise a leg release and a safety that independently retain the legs in an erect condition. In this embodiment, either the leg release or the safety includes a linkage connected to a touch bar.

0021The roll-in cot of the present invention allows the operator to place the collapsible legs in a deactivated condition without the legs collapsing and then to collapse the legs at the last possible moment before the cot is loaded on a platform. The roll-in cot minimises the likelihood of unintentional collapse of the legs of the cot by employing a touch bar associated with the collapsible legs. As the touch bar engages a platform the legs either are moved from a locked condition to a collapsible condition or are moved from a collapsible condition to a collapsed condition. In this manner unintentional or early operation of a handle or other release mechanism will not collapsed the cot or result in the operator having to bear the weight of the patient and the emergency cot for an extended period as it is loaded on to a platform.

0022In the present invention, collapsible legs are operable by a release assembly comprising a safety and a leg release as broadly described above. In a preferred embodiment, both the leading and trailing collapsible legs are operable by such a release assembly.

0023By employing a touch bar to operate either the leg release or the safety, the legs can only be collapsed with both the leg release and the safety in a deactivated condition. With either the leg release or the safety in an activated condition the legs remain in an erect condition supporting the patient. In this way the likelihood of an unintentional collapse of the roll-in cot is minimised.

0024The leg release and the safety typically include a linkage such as a latching assembly that retains the legs in an erect condition. Suitably a latching assembly may include a pin or other detent mechanism. In one form, the latching assembly may include a pin-in-slot to prevent movement or collapse of the legs. In another form, the latching assembly may include a hook that engages either an eye or a shaft.

0025The latching assembly may be operated by a touch bar or a suitable handle that is connected to the detent mechanism. A suitable handle may be directly connected to the detent mechanism in the form of a lever or may be connected by a cable or other suitable mechanism.

0026The safety may be a secondary latching assembly that also holds the legs in an erect condition. In this embodiment, the safety may be in similar form to that of the leg release save for one of either the safety or the leg release being operated by the touch bar.

0027Either the leg release or the safety incorporates a linkage connected to a touch bar whereby pushing the touch bar against a platform deactivates in the linkage.

0028The roll-in cot of the present invention allows the operator to activate the handle for collapsing the leading collapsible legs without the legs collapsing until a touch bar engages a platform. In this manner unintentional or early operation of the handle will not result in the collapse of the leading end of the cot.

0029The leading pair of collapsible legs is operable from a locked condition by a release assembly. In a preferred configuration the leg release may releasably engage a forwardly extending strut to as to allow the leading pair of collapsible legs to be pivoted towards the frame upon deactivation of the safety.

0030The leg release comprises a handle connected to a pawl. Preferably, the handle is located at the trailing end of the frame such that an operator manoeuvring the roll-in cot may readily access the handle from a position rearward of the roll-in cot. The pawl may be disposed at any convenient location on the frame. Preferably the pawl may be directly connected to the handle and engage the leading collapsible legs.

0031In a further embodiment of the present invention either the leg release or the safety may be operable by a proximity switch that senses whether the cot is positioned adjacent a platform such as a emergency vehicle. In combination with a touch bar operating the other of the leg release or the safety the cot my be safely loaded onto the platform without the operation being required to operate manual release.

0032The undercarriage of the roll-in cot of the present invention may find use in other applications as will be apparent to the skilled addressee.

0033In order that the invention may be more fully understood and put into practice, preferred embodiments thereof will now be described with reference to the accompanying drawings. <ul id="ul0001" list-style="none" compact="compact"><li><figref idref="f0001">Figure 1</figref> is a perspective view of a wheeled transporter according to one embodiment of the present invention.</li><li><figref idref="f0002">Figure 2A</figref> is a side view of the roll-in cot of <figref idref="f0001">Figure 1</figref> in a first position.</li><li><figref idref="f0002">Figure 2B</figref> is a top section view of the roll-in cot of <figref idref="f0002">Figure 2A</figref>, showing a corresponding position of a release assembly according to the present invention.</li><li><figref idref="f0003">Figure 3A</figref> is a side view of the roll-in cot of <figref idref="f0001">Figure 1</figref> in a second position.</li><li><figref idref="f0003">Figure 3B</figref> is a top section view of the roll-in cot of <figref idref="f0003">Figure 3A</figref>, showing a corresponding position of a release assembly according to the present invention.</li><li><figref idref="f0004">Figure 4A</figref> is a side view of the roll-in cot of <figref idref="f0001">Figure 1</figref> in a third position.</li><li><figref idref="f0004">Figure 4B</figref> is a top section view of the roll-in cot of <figref idref="f0004">Figure 4A</figref>, showing a corresponding position of a release assembly according to the present invention.</li><li><figref idref="f0005">Figure 5A</figref> is a side view of the roll-in cot of <figref idref="f0001">Figure 1</figref> in a fourth position.</li><li><figref idref="f0005">Figure 5B</figref> is a top section view of the roll-in cot of <figref idref="f0005">Figure 5A</figref>, showing a corresponding position of a release assembly according to the present invention.</li><li><figref idref="f0006">Figure 6A</figref> is a side view of the roll-in cot of <figref idref="f0001">Figure 1</figref> in a fifth position.</li><li><figref idref="f0006">Figure 6B</figref> is a top section view of the roll-in cot of <figref idref="f0006">Figure 6A</figref>, showing a corresponding position of a release assembly according to the present invention.</li><li><figref idref="f0007">Figure 7A</figref> is a side view of the roll-in cot of <figref idref="f0001">Figure 1</figref> in a sixth position.</li><li><figref idref="f0007">Figure 7B</figref> is a top section view of the roll-in cot of <figref idref="f0007">Figure 7A</figref>, showing a corresponding position of a release assembly according to the present invention.</li><li><figref idref="f0008">Figure 8A</figref> is a side view of a roll-in cot according to the present invention in a first position.</li><li><figref idref="f0008">Figure 8B</figref> is a top section view of the roll-in cot of <figref idref="f0008">Figure 8A</figref>, showing a corresponding position of a release assembly according to the present invention.</li><li><figref idref="f0009">Figure 9A</figref> is a side view of the roll-in cot of <figref idref="f0008">Figure 8A</figref> in a second position. <figref idref="f0009">Figure 9B</figref> is a top section view of the roll-in cot of <figref idref="f0009">Figure 9A</figref>, showing a corresponding position of a release assembly according to the present invention.</li><li><figref idref="f0010">Figure 10A</figref> is a side view of the roll-in cot of <figref idref="f0008">Figure 8A</figref> in a third position. <figref idref="f0010">Figure 10B</figref> is a top section view of the roll-in cot of <figref idref="f0010">Figure 10A</figref>, showing a corresponding position of a release assembly according to the present invention.</li><li><figref idref="f0011">Figure 11A</figref> is a side view of the roll-in cot of <figref idref="f0008">Figure 8A</figref> in a fourth position. <figref idref="f0011">Figure 11B</figref> is a top section view of the roll-in cot of <figref idref="f0011">Figure 11A</figref>, showing a corresponding position of a release assembly according to the present invention.</li><li><figref idref="f0012">Figure 12A</figref> is a side view of the roll-in cot of <figref idref="f0008">Figure 8A</figref> in a fifth position. <figref idref="f0012">Figure 12B</figref> is a top section view of the roll-in cot of <figref idref="f0012">Figure 12A</figref>, showing a corresponding position of a release assembly according to the present invention.</li><li><figref idref="f0013">Figure 13A</figref> is a side view of the roll-in cot of <figref idref="f0008">Figure 8A</figref> in a sixth position. <figref idref="f0013">Figure 13B</figref> is a top section view of the roll-in cot of <figref idref="f0013">Figure 13A</figref>, showing a corresponding position of a release assembly according to the present invention.</li><li><figref idref="f0014">Figure 14</figref> is an elevated perspective view of a leading part of a roll-in cot according another embodiment of the present invention.</li><li><figref idref="f0015">Figure 15A</figref> is a side view of the roll-in cot of <figref idref="f0014">Figure 14</figref> in a first position. <figref idref="f0015">Figure 15B</figref> is a top section view of the roll-in cot of <figref idref="f0015">Figure 15A</figref>, showing a corresponding position of a release assembly according to the present invention.</li><li><figref idref="f0016">Figure 16A</figref> is a side view of the roll-in cot of <figref idref="f0014">Figure 14</figref> in a second position. <figref idref="f0016">Figure 16B</figref> is a top section view of the roll-in cot of <figref idref="f0016">Figure 16A</figref>, showing a corresponding position of a release assembly according to the present invention.</li><li><figref idref="f0017">Figure 17A</figref> is a side view of the roll-in cot of <figref idref="f0014">Figure 14</figref> in a third position. <figref idref="f0017">Figure 17B</figref> is a top section view of the roll-in cot of <figref idref="f0017">Figure 17A</figref>, showing a corresponding position of a release assembly according to the present invention.</li><li><figref idref="f0001">Figure 1</figref> shows a roll-in cot 1 with the stretcher or patient support removed for the sake of clarity. The roll-in cot is formed from a frame 2 on which are pivotally mounted a leading pair of collapsible legs 3 and a trailing pair of collapsible legs 4. In the elevated condition shown, the roll-in cot 1 is supported on the leading pair of collapsible legs 3 and trailing pair of collapsible legs 4. The leading pair of collapsible legs 3 is locked into position by a support strut 5 that is locked to the frame 2. The trailing pair of collapsible legs is locked in position by a support strut 6 locked to the frame 2. A release assembly 7 is operated by a handle 8 that actuates a bar 9 by moving the bar 9 rearwardly relative to the roll-in cot 1.</li></ul>

0034On operation of the handle 8 so as to move the bar 9 in a rearward direction bar 9 is displaced laterally by arms 10 that are pivotally mounted to both the frame and to bar 9. Operation of the release assembly 7 will be described in further detail with reference to <figref idref="f0002 f0003 f0004 f0005 f0006 f0007">Figures 2A to 7B</figref>.

0035The release assembly 7 also includes a touch bar 11 for engagement with the rear of a platform. Actuation of touch bar 11 causes a cam 12 to be rotated on the frame 2. Rotation of the cam 12 on frame 2 allows the bar 9 to move further in a lateral direction.

0036In the collapsed position the frame has loading wheels 13 located on the frame 2 as well as on the leading space of the leading pair of collapsible legs 3 and the trailing pair of collapsible legs 4.

0037<figref idref="f0002">Figure 2A</figref> shows the roll-in cot 1 engaging the rear of an emergency vehicle 15 such as an ambulance. The loading wheels 13 that are disposed on the front of the frame 2 engage in emergency vehicle 15. In the first position the handle 8 is shown in <figref idref="f0002">Figure 2B</figref> in a neutral position as is the bar 9 and the cam 12. A pawl 14 is mounted on the bar 9 so as to cooperate with the camming surface 20 of the cam 12.

0038In a second position shown in <figref idref="f0003">Figure 3A</figref> the loading wheels 13 positioned at the front of frame 2 are further advanced onto the emergency vehicle 15. The handle 8 is moved to an activated position and the bar 9 is moved laterally relative to frame 2 by the rotation of arm 10 relative to the frame 2 and the bar 9 as shown in <figref idref="f0003">Figure 3B</figref>. In the activated condition pawl 14 is moved rearwardly with respect to the frame 2 and engages a stop on the camming surface 20 in this activated condition support strut 5 is slideably released from fixed engagement with the frame 2, thereby allowing the leading pair of collapsible legs 3 to rotate relative to the frame 2. The loading wheels 13 that are disposed on the leading pair of collapsible legs 3 are then able to engage the emergency vehicle 15 so as to assist in a supporting the roll-in cot 1.

0039<figref idref="f0004">Figure 4A</figref> shows the roll-in cot 1 in a third position with the loading wheels 13 further advanced on the emergency vehicle 15. The position of the handle 8 and the cam 12 in <figref idref="f0004">Figure 4B</figref> are the same as that shown in <figref idref="f0003">Figure 3B</figref>.

0040In <figref idref="f0005">Figure 5A</figref> the touch bar 11 has engaged the emergency vehicle 15. Operation of the touch bar 11 activates a push rod 22 shown in <figref idref="f0005">Figures 5B</figref> and causes the cam 12 to rotate relative to frame 2 about pivot 21. Rotation of cam 12 releases the pawl 14 from the stop on the camming surface 20 thereby slideably releasing the support strut 6 from locking engagement with the frame 2.

0041<figref idref="f0006">Figure 6A</figref> shows the roll-in cot 1 in a fifth position with the loading wheels 13 supporting the weight of the cot on the emergency vehicle 15, and with the support strut 6 folding under the frame 2 along with the trailing pair of collapsible legs 4. As shown in <figref idref="f0006">Figure 6B</figref>, as the handle 8 is positioned to it full release position adjacent the frame 2, the cam 12 rotates relative to frame 2 about pivot 21 such that the pawl 14 advances clearing the stop 23 on the camming surface 20.

0042<figref idref="f0007">Figure 7A</figref> shows the roll-in cot 1 fully advanced onto the emergency vehicle 15 with the loading wheels 13 positioned on the trailing pair of collapsible legs advanced onto the emergency vehicle 15. As shown in <figref idref="f0007">Figure 7B</figref>, releasing the handle 8 sends the pawl 14 forward of the stop 23 such that when the trailing pair of collapsible legs 4 are once again extended, the release assembly 7 resets to the locking position shown in <figref idref="f0002">Figure 2B</figref>.

0043<figref idref="f0008">Figure 8A</figref> shows a roll-in cot 30 having a leading pair of collapsible legs 33 and a trailing pair of collapsible legs 34, with a leading loading wheel 35 engaged to an emergency vehicle 36. The respective pairs of collapsible legs 33, 34 are rotatably mounted on frame 32. <figref idref="f0008">Figure 8B</figref> shows a handle 37 used to release of the leading pair of collapsible legs 33 and a primary lock 52 on the trailing pair of collapsible legs 34. A handle 38 is also provided to manually release the secondary lock 53, and is shown in the neutral position, as are bars 39 and 40 respectively.

0044<figref idref="f0009">Figure 9A</figref> shows the roll-in cot 30 in a second position with the leading pair of collapsible legs 33 partially collapsed. As shown in <figref idref="f0009">Figure 9B</figref>, the handle 37 has been moved to an activated condition whereby the bar 39 has advanced rearwardly relative to frame 32. By arm 41 pivotably mounted to frame 32 and to bar 39 the bar 39 is urged laterally causing support strut 42 to be slideably released from fixed engagement with the frame 32, thereby allowing the leading pair of collapsible legs 33 to rotate relative to the frame 32. The lateral movement of bar 39 also causes the primary lock 52 on the trailing pair of collapsible legs 34 to be released. At this stage, the trailing pair of collapsible legs 34 are still secured to frame 32 by secondary lock 53. <figref idref="f0010">Figures 10A and 10B</figref> show the roll-in cot 30 further advanced onto the emergency vehicle 36.

0045<figref idref="f0011">Figure 11A</figref> shows touch bar 51 in engagement with the emergency vehicle 36. Activation of touch bar 51 causes the secondary lock 53 on the trailing pair of collapsible legs 34 to be released. As shown in <figref idref="f0011">Figure 11B</figref>, operation of handle 38 is not required during loading of the roll-in cot. It is used in situations were the height of the cot with stretcher attached is used to assist in loading a patient onto the stretcher.

0046<figref idref="f0012">Figures 12A and 12B</figref> show the trailing pair of collapsible legs released, and <figref idref="f0013">Figures 13A and 13B</figref> show the roll-in cot 30 fully loaded onto the emergency vehicle 36.

0047<figref idref="f0014">Figure 14</figref> shows a leading portion of a roll-in cot 60 with the stretcher or patient support removed for the sake of clarity. The roll-in cot 60 is formed from a frame 62 on which are pivotally mounted a leading pair of collapsible legs 3 and a trailing pair of collapsible legs 4. In the elevated condition shown, the roll-in cot 1 is supported on the leading pair of collapsible legs (not shown) on a pivoting mount 63. The leading pair of collapsible legs (not shown) is locked into position by a support struts 65 that are locked to the frame 62 by cross member 66.

0048A release assembly is operated by a handle not shown that actuates a bar 69 by moving the bar 69 rearwardly relative to the roll-in cot 60. The release assembly includes a mechanism for releasing the trailing legs with in a manner similar to that shown in <figref idref="f0001 f0002 f0003 f0004 f0005 f0006 f0007">Figures 1 to 7B</figref>. Operation of the release assembly has been described in further detail with reference to <figref idref="f0002 f0003 f0004 f0005 f0006 f0007">Figures 2A to 7B</figref>.

0049Rearward movement of bar 69 also results in lateral movement as bar 69 is connected to lever 70 that is pivotally mounted to both bar 69 and frame 62. A pin 71 engages the cross member 66 when the handle is in a locked condition. Operation of the handle causes rearward movement of bar 69 and consequent lateral movement that withdraws pin 71 from the frame 69 and allows cross member 66 to slide against bar 69 thereby putting the leading collapsible legs (not shown) in a collapsible condition. Load wheel 72 has a touch bar 73 pivotally mounted in close proximity thereto. Touch bar 73 is connected to bar 74 across a fulcrum whereby rearward movement of the touch bar 73 results in forward movement of bar 74. The bar 74 is connected to a pivoting hook 75 across a fulcrum whereby forward movement of bar 74 lifts pivoting hook 75 away from cross member 66. In the inactivated condition in the pivoting hook 75 is urged to engage cross member 66 and preventing it moving rearwardly.

0050Arm 76 is pivotally connected to the frame 62 and rides up on cross member 66 as cross member 66 moves rearwardly. The leading end 77 of arm 76 engages the pivoting hook 75 and retains the bar 74 in a forward condition whereby the touch bar 73 is retained in a raised condition away from the platform so as to allow free movement of the cot 60.

0051<figref idref="f0015">Figure 15A</figref> shows the roll-in cot 60 engaging the rear of an emergency vehicle 85 such as an ambulance. The load wheels 72 that are disposed on the front of the frame 62 engage emergency vehicle 85. As similar with <figref idref="f0002">Figure2B</figref>, in the first position the handle 8 is shown in <figref idref="f0015">Figure 15B</figref> in a neutral position as is the bar 69 and the pin 71 (<figref idref="f0014">Figure 14</figref>).

0052In a second position shown in <figref idref="f0016">Figure 16A</figref>, the load wheels 72 positioned at the front of frame 62 are further advanced onto the emergency vehicle 85. The load wheels 72 engage the emergency vehicle 85 and touch bar 73 is urged rearwardly, urging link rod 74 in a forward direction. Safety hook 75 is rotated in a clockwise direction and out of engagement with cross member 66. The position of the handle in <figref idref="f0016">Figure 16B</figref> are the same as that shown in <figref idref="f0015">Figure 15B</figref>.

0053In the third position shown in <figref idref="f0017">Figure 17A</figref> left the arm 76 retains the safety hook 75 in a raised condition, thereby retaining the touch bar 73 in a raised condition of the emergency vehicle 85. The position of the handle in <figref idref="f0017">Figure 17B</figref> are the same as that shown in <figref idref="f0015">Figure 15B</figref>.

0054The operation of the trailing legs is similar to that shown in <figref idref="f0002 f0003 f0004 f0005 f0006 f0007">Figures 2A to 7B</figref>.

0055Persons skilled in the art will appreciate that the invention described above may be subject to improvements and modifications that will be apparent without departing from the spirit and scope of the invention described herein.