METHOD AND DEVICE IN AN EXTENSIBLE STRETCHER SLED

Abstract: The invention relates to a method and an arrangement relating to extensible stretcher sleds (3) for ambulance vehicles (1). The sled (3) can be moved manually between an inner (Fig. 1) and an outer (Fig. 2) end position in which the sled (3) projects beyond the rear end of the vehicle (1). Prior to collecting a patient, the sled (3) is moved to a position in the vicinity of its inner locked position and the rear door (2) of the vehicle (1) is moved to a near closed position or to a closed position. When returning with the patient, an operating device (13) is activated. This initiates automatic opening of the rear door (2) and automatic movement of the sled (3) to its outer end position/locked position. The arrangement comprises a gear rack (10) mounted on the sled (3), and electric motor (12) and a pinion wheel (11) carried by the motor such as to enable automatic opening of the rear door (2) and automatic movement of the sled (3) to its outer position.

Description: METHOD AND DEVICE IN AN EXTENSIBLE STRETCHER SLED The present invention relates to improvements in metcarriagesand arrangements in extensible stretcher sleds or carriages, and particularly in relation to ambulance vehicles in which the stretcher sled can be moved between an inner and an outer end position/locked position, and in which the sled can be extended beyond the rear end of the vehicle when said sled is located in its outer end position, so as to facilitate removal and deposit of a stretcher from and onto the sled. When collecting a patient for transportation by am¬ bulance, it is usual to leave the rear door of the ambulance open and the stretcher sled extended. This can result in undesirable cooling or chilling of the ambulance interior in cold weather conditions and it is possible that the rear door of the ambulance is left open for a period of such long duration as to cause the ambulance interior to become very cold indeed, which is naturally undesirable from the aspect of patient com¬ fort. In order to prevent the ambulance interior from becoming cold, the rear door of the ambulance must be closed subsequent to having removed the stretcher, which means that the rear door must be subsequently opened manually and the stretcher sled withdrawn, while balancing the patient and stretcher in some way or another, therewith subjecting the ambulance personnel and the stretcher-borne patient to serious risk. It will be understood that when the road surface or pave¬ ments are slippery and icy, there is a serious risk of slipping and sliding and overturning the stretcher, when endeavouring to balance the same while opening the ambulance door. Another reason why the rear door of an ambulance should be closed when collecting a patient is that there is less chance of impulsive theft of pharmaceuticals from the ambulance. A closed rear door of an ambulance will also prevent the ingress of exhaust gases during a patient-collecting period. The object of the present invention is to provide a method and an arrangement which will solve the afore¬ said problems. This object is achieved by a method and an arrangement having the characterizing features set forth in the following claims. The inventive method and arrangement provide many advantages. In addition to minimizing the extent to which warm air escapes from the vehicle interior, the risk of the theft of pharmaceuticals from the ambulance is also reduced, as is also the ingress of exhaust gases. Furthermore, the risk of injury to ambulance personnel is reduced, the spines of the personnel are subjected to less strain, and the stretcher-borne patient experiences a less adventuresome journey into the ambulance interior. Furthermore, existing ambulance vehicles can be readily equpiped with the inventive arrangement. The present invention will now be described in more detail with reference to an exemplifying embodiment thereof illustrated in the accompanying drawings, in which Figure 1 is a schematic, transparent perspective view of an ambulance section with the stretcher sled in a retracted position; Figure 2 shows the sled in an extended position; Figure 3 is a perspective view of a section of the inventive arrangement in an inactive position; and Figure 4 illustrates the arrangement of Fig. 3 in an active position. Fig. 1 illustrates schematically and in perspective the rear part of an ambulance vehicle 1, having a rear door 2 and a so-called extensible stretcher sled 3, said sled being shown positioned within the confines of the vehicle-interior. The stretcher sled 3 is intended to support a stretcher (not shown), and can be manouvered between an outer and an inner locked position, said sled being unlocked or released from said positions by manual activation of a lever 4 provided on the sled 3. The sled is locked automatically in its respective end positions. Fig. 1, shows the sled in its inwardly located end position, whereas Fig. 2 shows the sled in its extended, outward end position. The sled 3 rests on a support frame 5 provided, inter alia, with a number of rollers 6 which enable the sled 3 to move easily along the frame 5, between the outer and inner end-positions of said sled. Guide means are also provided for guiding the sled 3 in relation to the frame 5, so as to prevent the sled from leaving the frame. The aforedescribed sled 3 and frame 5 are known to the art and have long been used in ambulance vehicles to enable stretcher-borne patients to be placed in the ambulance and empty stretchers removed therefrom in a ready and easy fashion. This introduction and removal of stretchers into and out of the ambulance takes place essentially in the following manner. When the ambulance 1 has stopped at the address from which a patient is to be collected, the ambulance personnel open the rear door 2 of the ambulance and manipulate the operating lever 4 so as to unlock the stretcher sled 3 from its locked position within the ambulance interior (Fig. 1) and withdraw the sled 3 to its outer, locked position (Fig. 2). The stretcher resting on the sled 3 can then be readily reached and the ambulance personnel lift the stretcher from the sled and collect the patient. The stretcher, together with the patient, is then placed on the ex¬ tended sled 3 and the sled is released from its outer, locked position, by corresponding manipulation of the lever 4, whereafter the stretcher-carrying sled is pushed to its inward, locked position (Fig. 1) and the rear door 2 of the ambulance is closed. The ambulance is now ready to be driven away. It will be understood that while these events are taking place, the rear door of the ambulance remains open with the stretcher sled in its outwardly withdrawn position. As beforementioned, because the rear door is left open the ambulance interior will become very cold, and the ambulance is open to the ingress of exhaust gases and to impulsive theft of pharmaceuticals stored therein. Consequently, in order to prevent this it is necessary to manually retract the stretcher sled 3 to its inner end position and to close the rear door 2 of the ambulanace immediately after removing the stretcher from the stretcher sled. This means that when returning with a stretcher-borne patient it is necessary to lift and balance the stretcher manually while opening the rear door of the ambulance and extending the sled to its extended end position, all at the same time, before the stretcher and patient can be placed on the sled. It will be readily understood that this additional working requirement is ergonomically uncomfortable to ambulance personnel while the risk of the ambulance personnel slipping in wintery conditions is very high. Further¬ more, the patient is exposed to unnecessary additional risks during such working procedures of the ambulance personnel. In accordance with the present invention, the stretcher sled 3 and the frame 5 are modified in the following manner. The stretcher sled 3 is fitted with a gear rack 10 which extends in the direction of the longitudinal axis of the sled, as illustrated in Figs. 1 and 2. A gear or pinion 11 connected to an electric motor 12 is mounted adjacent the stretcher frame 5 or on some suitable part of the ambulance. The electric motor may suitably have the form of electric starting motor of the kind used, for instance, in automotive vehicles, said pinion wheel 11 being manouverable between an inactive position (Fig. 3) and an active position (Fig. 4). The pinion wheel 11 meshes with the rack 10, in the active position of the drive. Movement of the pinion wheel between its inactive and its active state is effected electromagnetically or by means of the elec¬ tric starting motor, which incorporates an axially dis- placeable rotor. Current is delivered to the electric motor 12 from the battery of the ambulance vehicle and the electric motor 12 can be rotated over a desired period of time such as to bring the pinion wheel 11 into mesh with the rack 10. The electrical circuit by means of which the electric motor 12 is operated includes an operating device in the form of a button 13 provided at a convenient height on the outside of the ambulance, in the vicinity of the rear door 2, see Figs. 1 and 2. The electrical circuit also includes a microswitch (not shown) which is opera- tive to interrupt the current supply to the circuit, i.e. to stop further outward movement of the sled 3 when said sled has reached its outer end position. The circuit includes a further microswitch (not shown) which is operative to interrupt the current supply to the circuit, i.e. to prevent the electric motor 12 from starting, when the rear door 2 of the ambulance has been closed to a locked position, in order to prevent unintentional extension of the stretcher sled, for instance when driving the ambulance. The circuit also includes a third microswitch (not shown) which func¬ tions to interrupt current supply to the electric motor 12 when the stretcher sled 3 is locked in its inner position. The inventive arrangement operates in the following manner. When the ambulance 1 has stopped at an address from which a patient is to be collected, the ambulance personnel open the rear door 2 of the ambulance, release the stretcher sled 3 from its internal, locked position by manouvering the lever 4 and manually with¬ draw the sled 3 to its outer locked position/end posi¬ tion shown in Fig. 2. This can be accomplished, because the pinion wheel 11 is then in its inactive state, shown in Fig. 3, and thus out of engagement with the rack 10. The personnel then remove the stretcher from the sled 3 and push the sled manually to the vicinity of its inner, locked position, although not entirely to this position, whereafter the rear door 2 is closed, although not to its fully locked position. The ambu¬ lance personnel then collect the patient. When return¬ ing with the stretcher-borne patient, the ambulance personnel take the following steps. One of the stretch¬ er bearers presses the operating button 13, which can be done with his/her elbow, due to the convenient position of said button, without jeopardizing the balance of the stretcher bearers. Naturally, the stret¬ cher bearers/ambulance personnel must not stand within the swinging radius of the rear door 2 when pressing the button 13, since they, or the stretcher will then be struck by the door as it is automatically opened, or by the stretcher sled when it is automatically extended from its position within the ambulance. Pressing of the operating button will initiate the supply of current to the electric motor 12, which causes the pinion wheel 11 to move from its inactive position, shown in Fig. 1, into meshing engagement with the rack 10 on the sled 3, the rotor of the electric motor 12 and the pinion wheel 11 rotating in the direction shown by the arrow A, causing the rack 10 and thus the sled 3 to move in the direction of arrow B, i.e. the sled 3 is moved to its outer end position, in which it is fixated automati¬ cally in accordance with the aforesaid. As the stret¬ cher sled 3 moves towards its extended position, the sled opens or knocks-up the closed rear door 2 automa¬ tically. As beforementioned, a microswitch interrupts the supply of current to the electric motor 12 when the stretcher sled 3 has reached its outer locked posi¬ tion/end position (Fig. 2), therewith stopping rotation of the electric motor 12 and causing the gear wheel 11 to move to its inactive position, shown in Fig. 3, and out of meshing engagement with the rack 10. The stretcher bearers/ambulance personnel can now comfortably place the stretcher-borne patient on the outwardly extending sled 3, in the aforedescribed manner, and then release the sled from its outer locked position, by appropriate manouvering of the lever 4, and then push the sled to its inner, locked position, shown in Fig. 3, and close the rear door 2. The am¬ bulance can now be driven away. When the ambulance vehicle is equipped, for instance, with a central locking system, the rear door 2 need not be carefully moved to an almost closed and locked position when the ambulance personnel leave the am¬ bulance to collect a patient, and the rear door can instead be closed and locked and means can be provided which upon activating the operating button 13 automati¬ cally release the rear door so that the door can be opened by the sled 3. It will be understood that the inventive arrangement can be used in vehicles other than ambulance vehicles where automatic extension of a sled is desired. The invention is thus not restricted to the illustrated and described embodiments, since these embodiments can be modified and changed within the scope of the follow¬ ing claims.

Claims: CLAIMS 1. A method for operating extensible stretcher sleds (3) particularly in connection with ambulance vehicles (1) , comprising moving the sled (3) between an inner (Fig. 1) and an outer (Fig. 2) end position/locked position, such that the stretcher sled (3) will project beyond the rear end of the vehicle (1) when said sled is located in its outer end position, therewith facili¬ tating removing and placing a stretcher from and onto the sled (3), characterized by, prior to collecting a patient, moving the stretcher sled (3) to a position in the vicinity of its inner, locked position; closing the rear door (2) of the vehicle (1) to a near closed position; upon returning with the stretcher-borne patient activating an operating device (13) mounted on the vehicle exterior such as to initiate automatic opening of the rear door (2) of the vehicle (1) and automatic displacement of the stretcher sled (3) to its outer end position/locked position. 2. An extensible stretcher-sled arrangement, particu¬ larly relating to ambulance vehicles (1) , in which the stretcher sled (3) can be extended between an inner (Fig. 1) and an outer (Fig. 2) end position/locked position, and in which the sled (3) projects beyond the rear end of the vehicle (1) when said sled is located in its outer end position, so as to facilitate removal of a stretcher from said sled and the deposit of a stretcher-borne patient thereonto, characterized by means (10,12) operative to open the rear door (2) of the vehicle (1) automatically and to automatically displace the stretcher sled (3) from a position in the vicinity of its end position/locked position; and by operating means (13) mounted on the vehicle exterior and operative to initiate said automatic opening and displacement movements. 3. An arrangement according to Claim 2, characterized in that said means include a rack (10) mounted on the stretcher sled (3), an electric motor (12) mounted in a remaining part of the vehicle (1) and a gear or pinion wheel (11) carried by the motor (12) and intended to be moved between an inactive position, in which the pinion wheel (11) is free from engagement with the rack (10), and an active position in which said pinion wheel (11) is in engagement with said rack (10). 4. An arrangement according to Claim 2 or 3, charac¬ terized in that the operating device is an operating button (13) . 5. An arrangement according to Claim 3 or 4, charac¬ terized by means for interrupting the supply of current to the electric motor (12) when the stretcher sled (3) is located in its outer end position/locked position. 6. An arrangement according to any of Claims 3-5, characterized by means for interrupting the supply of electric current to the electric motor (12) when the stretcher sled (3) is located in its inner end posi¬ tion/locked position. 7. An arrangement according to Claim 5 or 6, charac¬ terized in that said current interrupting means have the form of microswitches.

Inventors: FORSBERG TORSTEN, FORSBERG, TORSTEN
Applicants: HEJDE AMBULANSER AB, HEJDE-AMBULANSER AB
Application year: 1989
Main classification: A61G3
IPC codes: A61G3