Construction Of A Trolley

Abstract

A trolley for use particularily with ambulances and in hospitals which can be readily raised or lowered, fully collapsed to act as a stretcher, or folded to lie on a raised platform, the trolley having a stretcher framework which has two pairs of pivotally mounted wheel supporting legs. The legs on each side of the trolley engage in a scissors like manner and are adapted for relative movement to raise and lower the trolley so that the stretcher framework is always horizontal. Means are also provided to allow the legs to be folded rapidly.

Description

This invention relates to a construction of trolley and in particular to a construction of trolley for use in hospitals and with ambulances.

In transporting patients to or from a hospital and/or within a hospital one of the problems invariably encountered is the necessary physical effort required of the hospital staff to lift the patients from one level to another, i.e., from a stretcher into an ambulance or from a fixed structure trolley on to an operating table. It will be readily appreciated that in very many instances the actual lifting movement is physically demanding on the hospital staff and can prove injurious to the patient. Injuries are likely to occur in accident cases where the patient must be moved from the scene of the accident on to a stretcher, from the stretcher into an ambulance and from the ambulance into the hospital. It is therefore a principal object of the present invention to provide a trolley that may be raised and lowered rapidly while maintaining the patient in a horizontal position.

A further object of the invention is to provide a trolley the legs of which may be readily folded for entry into for example an ambulance while at the same time ensuring that the legs cannot be inadvertently folded during use with the consequent risk of injury to a patient.

A still further object of the invention is to provide a trolley that can be rapidly collapsed for use as a stretcher.

Further objects and advantages of the invention will become apparent to those skilled in the art on further reading this specification.

The invention will be more clearly understood from the following description of a preferred embodiment thereof given by way of example only with reference to the accompanying drawings in which

FIG. 1 is a side view of a trolley according to the invention in the fully assembled position,

FIG. 2 is a plan view of the trolley,

FIG. 3 is a side view of the trolley being pushed onto a platform,

FIG. 4 is a side view of the trolley collapsed for transport,

FIG. 5 is a cross-sectional view in the direction of the arrows V -- V of FIG. 1.

FIG. 6 is a perspective view of portion of the trolley, in the assembled position,

FIG. 7 is a perspective view of another portion of the trolley in the assembled position, and

FIG. 8 is a perspective view of the portion of the trolley illustrated in FIG. 7 as the trolley is being collapsed.

Referring to the drawings the trolley comprises a stretcher framework 1, a pair of front legs 2 pivotally mounted at 3 on the stretcher framework 1, a pair of rear legs 4 pivotally mounted at 5 on the stretcher framework 1, securing means, indicated generally by the reference numeral 6, for releasably interconnecting a front leg 2 with the rear leg 4 on the same side of the trolley and a stay member 7 mounted between the front legs 2 and the stretcher framework 1.

The stretcher framework 1 which is manufactured from tubular steel or polished aluminum comprises two sets of longitudinal side bars 10, a front bar 11 and an end bar 12. A cross-bar 13 is mounted between the side bars 10. A pair of parallel longitudinal rails 14 is supported between the cross-bar 13 and the end bar 12. A plate 15 is mounted on each side bar 10 adjacent the front bar 11, and carries a wheel 16. Fixed upstanding support rails 17, for clarity illustrated by interrupted lines, are provided to assist in retaining a patient in position. A socket 18 having an outer top face 19 is provided on each of the side bars 10.

The front legs 2 are manufactured from flat plate and carry a transverse axle 20 which is used to support a ground engaging wheel 21 on each of the front legs 2. It will be noted that the wheels 21 form the rear wheels of the trolley. The rear legs 4 are each manufactured from flat plate and carry a spaced apart length of tubing 22 which is bent adjacent its upper end to form a handle 23. A stub axle 24 mounted between the rear leg 4 and the tubing 22 carries a ground engaging wheel 25. The wheels 25 are the front wheels of the trolley.

The securing means 6 is formed by a curved track 30 mounted on the front leg 2 and a wheel 31 mounted on the rear leg 4. The curved guide track 30 is grooved to engage the wheel 31. A lower support track 32, also grooved is provided to engage the wheel 31 when the wheel 31 is not in contact with the track 30. The wheel 31 is mounted on a stub axle 33 which is in turn mounted in an elongated slot 34 in the rear leg 4. The stub axle 33 is constrained laterally in the slot 34 by a pair of circular discs 35. The slot 34 is downwardly inclined to the longitudinal axis of the rear leg 4 and is provided with a downwardly directed recess 36 at its upper end (see FIGS. 1 and 3). A cranked lever 37 is pivotally mounted at 38 is on the rear leg 4 adjacent the recess 36. One end 42 of the cranked lever 37 is adapted in use, as will be described below, to bear against the disc 35 to eject the steel axle 33 out of the recess 36. The other end of the cranked lever 37 is provided with a lip 39 for engagement with the socket 18. The cranked lever 37 is pivoted by means of a cable housed in an exterior cable 40 and a hand operated lever 41 mounted on the handle 23.

The stay member 7 is a tubular framework having an upper bar 50, a lower bar 51 two side bars 52 and internal diagonal bracing bars 53. The lower bar 51 is pivotally mounted at its ends 54 on the front legs 2. A pair of spaced apart support plates 55 are mounted on the upper bar 50. A shaft 56 is mounted between each support plate 55 and the adjacent side bar 52. Each shaft 56 forms an inwardly directed lug 57 from the support plate 55 and also the support for a grooved wheel 58. A hook 59 is pivotally mounted on each shaft 56 and embraces the rail 14. It will be noted from FIGS. 7 and 8 that the hooks 59 are so constructed as to allow the wheels 58 disengage the rails 14 in certain circumstances as will be described below, and to hang from the hooks 59.

A lead screw 60 is mounted in a bearing 62 on the cross bar 13 and in a tube 61 mounted on the end bar 12.

The lead screw 60 is provided with a handle 63. A threaded block 64 is mounted on the lead screw 60 and is grooved at 65 to engage a guide bar 66. The guide bar 66 is mounted between the end bar 12 and the cross bar 13, above and spaced apart from the lead screw 60. The guide bar 66 constrains the threaded block 64 to move along the lead screw 60 when the handle 63 is rotated.

A cover member 67 having a chamfered edge 67a is pivotally mounted at 68 on the threaded block 64 a return spring 69 is secured between the cover member 67 and the threaded block 64. The cover member 67 is provided with a pair of cut-out slots 70 which engage the lugs 57 on the stay member 7. The dimensions of the slots 70 are such that the cover member 67 can only by pivoted so as to disengage the lugs 57 from the slots 70 when the stay member 7 is hanging by the hooks 59 from the rails 14.

Pivotal movement of the cover member 67 is achieved by means of a length of wire 71 connected at 72 to the cover member 67 and fed through a hole 73 in the cross-bar 13, around a pulley block 74, mounted on the cross bar 13, through another hole 75 in the cross bar 13 to a coil spring 76, from the coil spring 76 through a hole 77 in the end bar 12 through a hole 78 in a bar 79, mounted on the tube 61. The wire 71 is then led through a hollow handle 80 back through another hole 81 in the bar 78 through a hole 82 in the end bar 12 to the threaded block 64 at 83. It will be appreciated that as the threaded block 64 travels along the lead screw 60 that the wire will be constrained to move over the pulley block 74 and through the handle 80.

In operation, with the trolley in the assembled position as illustrated in FIG. 1, when it is desired to alter the height of the trolley the handle 63 is operated to rotate the lead screw 60. Rotation of the lead screw 60 causes the threaded block 64 and hence the upper bar 50 of the stay member 7 to be moved towards or away from the end bar 12 to lower or raise the trolley. As the stay member 7 moves relative to the stretcher framework 1 each wheel 31 moves against its track 30. Each front leg 2 and rear leg 4 performing a substantially scissors like movement.

Referring in particular to FIG. 3, when it is desired to place the trolley in a folded position on a platform, identified by the reference numeral 90 in FIG. 3, the trolley is pushed against the platform 90 with its wheels 16 above or resting on the platform 90. The handle 63 is rotated to cause the upper bar 50 of the stay member 7 to move towards the end bar 12. Initially this lowers the whole trolley if the wheels 16 are not in contact with the platform 90, with the wheels 16 in contact with the platform 90 further movement of the upper bar 50 towards the end bar 12 causes the weight of the trolley and patient to be borne on the wheels 16 and the wheels 21 [see FIG. 3]. It will be appreciated that there is now no pressure being exerted downwards by the track 30 on the wheels 31. Each lever 41 is operated causing the end 42 of the cranked lever 37 to pivot against its adjacent disc 35. As there is no pressure on the wheel 31 the stub axle 33 is forced out of the recess 36 and into the main portion of the slot 34. The handle 23 may be pivoted downwards raising the rear leg 4 to lie alongside the stretcher framework 1 as illustrated by the interrupted lines in FIG. 3. When the rear leg 4 is fully raised the lip 39 lies across the outer top face 19 of the socket 18.

The trolley is now pushed forward on the platform 90 until portion of the front legs 2 bear against the platform 90. When the front legs 2 bear against the platform 90 the weight of the trolley is on the wheels 16, and wheels 21. The user lifts the trolley slightly thus removing the weight off the wheels 21. There is however no weight being taken by the stay member 7 which will thus under its own weight pivot downwards about the ends 54 of its lower bar 51. The stay member 7 will only pivot downwards a small distance when the hooks 59 will prevent further movement away from the rails 14. The hollow handle 80 is pulled backwards causing the wire 71 to be drawn backwards through the holes 78, 77 and 75 around the pulley block 74 and through the hole 73 thus pivoting the cover member 67 about its pivot point 68 and raising the slots 70 out of engagement with the lugs 57 [see FIGS. 7 and 8] . With the stay member 7 disengaged from the lead screw 60 the front legs 2 may be pushed forward on to the platform 90. Once the hollow handle 80 is released the return spring 69 cause the cover member to assume its former position. When the trolley is pushed fully home on the platform it rests on the wheels 21 and 25.

When the trolley is removed rearwards from the platform 90 the front legs 2 will pivot downwards. As the front legs 2 pivot downwards the stay member 7 will be supported by the hooks 59 as it moves away from the end bar 12. Further movement of the stay member 7 and the front legs 2 is prevented by the cover member 67 bearing against the lugs 57. The lugs 57 bear against the chamfered edge 67a of the cover member 67 thus pivoting it and offering the slots 70 up to the lugs 57. The weight of the trolley is transferred to the wheels 21 and the lugs 57 engage the slots 70. The trolley is withdrawn further until the wheels 25 are clear of the platform 90. The lever 41 is operated causing the cranked lever 37 to pivot to disengage the lip 39 from the top face 19 of the socket 18. The rear legs 4 pivot downwards the wheels 31 rolling on the lower support track 32 and the stub axles 33 in the slots 34 until they engage the recesses 36. The handle 63 is rotated until the weight of the trolley is on the wheels 21 and 25.

When it is desired to collapse the trolley for transportation or for use as a stretcher the trolley is raised at both ends so that the wheels 21 and 25 are clear of the ground. The rear legs 4 are now hanging by the stay member 7, and hooks 59 from the rails 14. The hollow handle 80 is withdrawn and held as the trolley is lowered on to the ground. The lugs 57 disengage from the slots 70 and the trolley folds downwards the lip 39 of the cranked lever 37 engaging the socket 18. It will be appreciated that this collapsed position of the trolley is not the same position as the folded position already described as the stub axles 33 are each in their appropriate recess 36. To reassemble the reverse procedure as followed.

It will be appreciated that the present invention provides a construction of trolley which may be positioned at any desired normal trolley height, which may be varied in position as to height at any time whether loaded or not and which may be collapsed to a convenient size simply and rapidly.

Further it will be appreciated that the trolley cannot be collapsed or folded when supporting a weight on its four legs. In practice the weight of the trolley itself is sufficient to prevent its inadvertent collapsing.

While the present invention has been described above with particular relevence to its use as a hospital trolley, it must be clearly understood that the trolley has many applications and may readily be utilized in any activity requiring the transportation of a load from one location to another.

Claims

I claim:

1. A trolley for use particularly with ambulances and in hospitals which comprises;

a stretcher framework;

a pair of front legs pivotally mounted on the stretcher framework;

a pair or rear legs pivotally mounted on the stretcher framework, each rear leg crossing in a scissors like manner the front leg on the same side of the trolley;

means for releasably interconnecting on each side of the trolley the front and rear legs, said means for releasably interconnecting on each side of the trolley the front and rear leg comprises;

a wheel mounted on the rear leg;

a curved guide track mounted on the front leg whereby the track engages and rests upon the wheel; the shape of the track being such that as the trolley is raised or lowered the stretcher framework remains substantially horizontal; and

means for moving the wheel relative to the rear leg for disengagement with the track;

leg movement control means on the stretcher framework for raising and lowering the trolley maintaining the stretcher framework substantially horizontal and

a stay member pivotally mounted on one of the pairs of legs and connected to the leg movement control means.

2. A trolley as recited in claim 1 wherein the rear leg has an elongated slot downwardly inclined to the longitudinal axis of the rear leg and having a downwardly directed recess at its end nearer to where the rear leg is pivotally mounted on the stretcher framework and the wheel is mounted on an axle which engages the slot.

3. A trolley as recited in claim 2 wherein the means for moving the wheel relative to the rear leg for disengagement with the curved track comprises:

a cranked lever pivotally mounted on the rear leg adjacent the recess in the slot; and

means for pivoting the lever against the wheel to force it out of the recess.

4. A trolley as recited in claim 3 wherein latch means are provided on the stretcher framework for releasably engaging the cranked lever when the legs are pivoted upwards to lie along the stretcher framework.

5. A trolley as recited in claim 1 wherein the leg movement control means comprises:

means for slidably mounting the stay member on the stretcher framework;

a block, having a threaded hole, releasably connected to the stay member;

a lead screw mounted on the stretcher framework and engaging the threaded hole; and

means for preventing rotation of the block relative to the stretcher framework.

6. A trolley as recited in claim 5 wherein:

the stretcher framework is provided with a pair of parallel longitudinal rails which the stay member engages and depends from, whereby the stay member is permitted limited movement away from the rails;

a pair of inwardly directed lugs are secured to the stay member; and

a cover member is pivotally mounted on the block, the cover member having a pair of cut-out slots for engagement with the lugs, the dimensions of the slots being such that the cover member can only be pivoted out of engagement with the lugs when the stay member is depending and spaced apart from the rails.

7. A trolley as recited in claim 1 wherein the leg movement control means comprises:

means for slidably mounting the stay member on the stretcher framework;

a block, having a threaded hole, connected to the stay member;

a lead screw mounted on the stretcher framework and engaging the threaded hole; and

means for preventing rotation of the block relative to the stretcher framework.

8. A trolley as recited in claim 7 wherein:

the stretcher framework is provided with a pair of parallel longitudinal rails which the stay member engages and depends from, whereby the stay member is permitted limited movement away from the rails;

a pair of inwardly directed lugs are secured to the stay member; and

a cover member is pivotally mounted on the block, the cover member having a pair of cut-out slots for engagement with the lugs, the dimensions of the slots being such that the cover member can only be pivoted out of engagement with the lugs when the stay member is depending and spaced apart from the rails.

9. A trolley as recited in claim 2 wherein the leg movement control means comprises:

means for slidably mounting the stay member on the stretcher framework;

a block, having a threaded hole, connected to the stay member;

a lead screw mounted on the stretcher framework and engaging the threaded hole; and

means for preventing rotation of the block relative to the stretcher framework.

10. A trolley as recited in claim 9 wherein:

the stretcher framework is provided with a pair of parallel longitudinal rails which the stay member engages and depends from, whereby the stay member is permitted limited movement away from the rails;

a pair of inwardly directed lugs are secured to the stay member; and

a cover member is pivotally mounted on the block, the cover member having a pair of cut-out slots for engagement with the lugs, the dimensions of the slots being such that the cover member can only be pivoted out of engagement with the lugs when the stay member is depending and spaced apart from the rails.

11. A trolley as recited in claim 3 wherein the leg movement control means comprises:

means for slidably mounting the stay member on the stretcher framework;

a block, having a threaded hole, connected to the stay member;

a lead screw mounted on the stretcher framework and engaging the threaded hole; and

means for preventing rotation of the block relative to the stretcher framework.

12. A trolley as recited in claim 11 wherein:

the stretcher framework is provided with a pair of parallel longitudinal rails which the stay member engages and depends from, whereby the stay member is permitted limited movement away from the rails;

a pair of inwardly directed lugs are secured to the stay member; and

a cover member is pivotally mounted on the block, the cover member having a pair of cut-out slots for engagement with the lugs, the dimensions of the slots being such that the cover member can only be pivoted out of engagement with the lugs when the stay member is depending and spaced apart from the rails.

13. A trolley as recited in claim 12 wherein the stretcher framework is provided with one or more wheels adjacent its front end.

14. A trolley as recited in claim 12 wherein a handle is provided on each of the rear legs to facilitate movement of the trolley and pivoting of the rear legs.