Abstract:
A stretcher comprising a frame having at least two parallel upper guides incorporated in said frame on the front and rear sides, respectively, for guiding a belt portion which is capable of supporting a human body, and at least two lower guides likewise incorporated in the frame on the front and rear sides, respectively, for guiding a belt portion which is in contact with the ground. Both ends of the belt portion guided over the upper guides are coupled to a coupling member incorporated in the frame so as to be movable in the direction of movement of the stretcher. The two ends of the belt portion guided over the lower guides are also coupled to said movable member.
Application Number:
05/155584
Publication Date:
01/01/1974
Assignee:
U.S. Philips Corporation (New York, NY)
International Classes:
A61G1/003; A61G7/10; A61G1/02
Field of Search:
5/60,81,81R,82,86
US Patent References:
| 3654644 | STRETCHER | April 1972 | Stevens | |
| 3418670 | Roller stretcher | December 1968 | Morgan | |
| 3579672 | | May 1971 | Koll et al. | |
| 3493979 | METHOD AND APPARATUS FOR MOVING OBJECTS | February 1970 | Koll et al. | |
Primary Examiner:
Nunberg, Casmir A.
Attorney, Agent or Firm:
Trifari, Frank R.
Claims:
What is claimed is
1. A stretcher comprising a pair of upright side frames, first and second parallel upper guides carried between said side frames on the front and rear respectively of said stretcher, at least two lower guides carried between said side frames on the front and rear of said stretcher, a first belt portion of finite length for supporting a human body guided for movement between said first and second upper guides, a second belt portion of finite length guided for movement between said lower guides in contact with the ground so that when said second belt portion is moved in one direction said stretcher will be propelled along the ground in the opposite direction at an equal speed, a coupling member supported by said frame for movement in the direction of movement of said stretcher, the corresponding ends of said first and second finite belt portions being coupled to said coupling member so that as said coupling member is moved said first and second belt portions will be caused to move in the same direction and at the same speed, and means connected to said coupling member for causing movement thereof.
2. A stretcher comprising a pair of upright side frames, first and second parallel upper guides carried between said side frames on the front and rear respectively of said stretcher, at least two lower guides carried between said side frames on the front and rear of said stretcher, a first belt portion of finite length for supporting a human body guided for movement between said first and second upper guides, a second belt portion of finite length guided for movement between said lower guides in contact with the ground so that when said second belt portion is moved in one direction said stretcher will be propelled along the ground in the opposite direction at an equal speed, a coupling member supported by said frame for movement in the direction of movement of said stretcher, the corresponding ends of said first and second finite belt portions being coupled to said coupling member so that as said coupling member is moved said first and second belt portions will be caused to move in the same direction and at the same speed, and means connected to said coupling member for causing movement thereof, said coupling member comprising a pair of rollers, corresponding ends of said first and second belts being connected to each other, said connected ends being guided over one of said rollers.
3. A stretcher comprising a pair of upright side frames, first and second parallel upper guides carried between said side frames on the front and rear respectively of said stretcher, at least two lower guides carried between said side frames on the front and rear of said stretcher, a first belt portion of finite length for supporting a human body guided for movement between said first and second upper guides, a second belt portion of finite length guided for movement between said lower guides in contact with the ground so that when said second belt portion is moved in one direction said stretcher will be propelled along the ground in the opposite direction at an equal speed, a coupling member supported by said frame for movement in the direction of movement of said stretcher, the corresponding ends of said first and second finite belt portions being coupled to said coupling member so that as said coupling member is moved said first and second belt portions will be caud to move in the same direction and at the same speed, and means connected to said coupling member for causing movement thereof, and a guide plate for extending between said first and second upper guides for supporting said first belt portion guided therebetween.
Description:
The invention relates to a stretcher comprising a frame having at least two parallel upper guides incorporated in said frame on the front and rear side, respectively, for guiding a belt portion which can support a human body and at least two lower guides likewise incorporated in the frame on the front and rear side, respectively, for guiding a belt portion which is in contact with the ground. The two belt portions move at the same speed and in the same direction relative to the frame.
A stretcher of the type to which the present invention relates is known from the U.S. Patent Specification 3,418,670. The two belt portions in said known stretcher are each formed of an endless belt which is wound around the upper and lower guides, respectively. The two endless belts are locally in frictional contact so that when one belt is driven the other is taken along by friction.
The drawback of this known stretcher is its rather complicated construction in which in particular the replacement of the endless belts is difficult and time-consuming. In addition there is the danger that, since only one of the belts is driven positively and the other is taken along by friction, slip may occur so that the speed of the two belts becomes different. The result of this is that there may be relative movement between the patient to be lifted and the upper belt, so that the possibility exists that the patient will experience forces which may change his posture possibly resulting in his condition getting worse.
It is the object of the invention to provide a stretcher in which the above-mentioned drawbacks are avoided.
The stretcher according to the invention is characterized in that both ends of the belt portion, which is guided over the upper guides, are coupled to a coupling member incorporated in the frame so as to be movable in the direction of movement of the stretcher. The two ends of the belt portion guided over the lower guides is also coupled to said movable coupling member. In this manner a stretcher is obtained in which the two belt portions move at an exactly equally large speed and in the same direction relative to the frame by the movement of the coupling member. Replacement of the two belt portions can be done very easily by detaching them from the coupling member.
In a further embodiment of the stretcher according to the invention the ends of the belt portion guided over the upper guides are connected to the corresponding ends of the belt portion guided over the lower guides. The coupled ends are each guided over an associated guide roller which forms part of the movable coupling member. So in this embodiment the stretcher comprises. When one endless belt when the coupling member is moved it moves at the same speed and in the same direction relative to the frame over the upper and lower guides.
In order that the invention may be readily carried into effect, one embodiment of a stretcher according to the invention will now be described in greater detail, by way of example, with reference to the accompanying diagrammatic drawings which are not drawn to scale and in which FIGS. 1, 2 and 3 are two cross-sectional views and a plan view, respectively, of the stretcher according to the invention.
The drawing shows a stretcher the frame of which is formed by two side plates 1 and 2 between which a guide plate 3 is secured. In the side plates 1 and 2 are incorporated two upper guide rollers 4 and 5, the roller 4 of which is situated on the rear side and the roller 5 of which is situated on the front side. Incorporated in said side plates 1 and 2 are furthermore a lower guide roller 6 on the rear side and a lower guide roller 7 on the front side; a number of further guide rollers 8 are incorporated between the guide rollers 6 and 7. A belt portion 9 for supporting a human body is guided over the guide rollers 4 and 5. Guide plate 3 prevents sagging of the belt when it is located between guide rollers 4 and 5. A further belt portion 10 is guided over the guide rollers 6, 7 and 8. One side of the belt portion 9 extends from roller 5 to a guide roller 11 while one side of belt portion 10 also extends from roller 7 to guide roller 11 where the two belt portions are connected together so that one belt is formed. The other side of the belt portion 9 extends from roller 4 to a guide roller 12, while the other side of belt portion 10 also extends to said guide roller 12 where the two ends are connected together so that one endless belt is obtained.
At their ends the guide rollers 11 and 12 are journalled in guide blocks 13 which are movable in slotted guides 14 in the side plates 1 and 2. In this manner a movable coupling member for the belt portions 9 and 10 is obtained. In the blocks 13 the guide rollers 11 and 12 are drawn towards each other by a tensioning spring 15 so that the belt 9, 10 is always tensioned. The blocks 13 each comprise a nut 16 in which a screw spindle 17 is incorporated which extends along the side plates 1 and 2. On the rear side of the stretcher the screw spindles 17 are each provided with a worm wheel 18 which cooperates with a common worm 19 which can be rotated by means of a hand wheel 20.
By operating the hand wheel 20, the worm wheels 18 and screw spindles 17 are rotated by the worm 19 so that the nuts 16 and hence the blocks 13 start moving along the screw spindles 17. This means that the guide rollers 11 and 12 start moving in the longitudinal direction of the stretcher as a result of which, for example, upon movement of rollers 11 and 12 from the rear side to the front the belt portion 9 moves from roller 5 to roller 4, so to the left in FIG. 1, while the belt portion 10 moves from roller 7 to roller 6, so likewise to the left. Since belt portion 10 is stationary relative to the ground, this means that the frame will start moving to the right at the same speed but opposite to the belt portion 9. This means that the belt portion 9 has no movement relative to a patient to be lifted so that said patient experiences substantially no forces and can be lifted without variation of posture. In this embodiment the belt portions 9 and 10 are united to form an endless belt which is guided over the rollers 11 and 12 of a movable coupling member. In circumstances it is also possible to omit the rollers 11 and 12 and rigidly secure the ends of the belt portions 9 and 10 to the coupling member.