Winch for raising and lowering persons

The invention relates to a winch (6) for raising and lowering persons, of the type that comprises a housing with an attachment member (16), an electric motor (39) driving a reel (27), a lifting strap (7) connected to the reel for winding and unwinding the lifting strap whereby the lifting strap is guided through one of two openings (17,19) formed in the housing.

The present invention relates to a winch for raising and lowering persons, comprising a housing provided with a first attachment member, a first opening formed in the housing substantially opposite to the first attachment member, an electric motor coupled to the input of a reduction gearing, a reel component coupled to the output of the reduction gearing, and a flexible elongated traction member connected to the reel component for winding and unwinding the traction member for raising and lowering a person. Further, the invention relates to the use of a winch according to the invention as a ceiling lift. The invention also relates to a ceiling lift assembly, comprising an overhead rail with at least one carriage guided therein, the carriage being provided with an attachment member, a winch provided with at least one attachment member on the winch housing and the winch comprising a flexible elongated traction member with an attachment member on its free end and a spreader bar with an attachment member.

BACKGROUND ART

U.S. Pat. No. 6,085,368 discloses a winch of the above type, that is used as a ceiling lift. Ceiling lifts have the advantage with respect to floor lifts with a mast and a lifting arm arrangement that they do not occupy any floor space. In certain rooms the ceiling lift may only be used on relatively few occasions, and it would be inefficient to keep a winch in such a room continually. Installing winches in a room only for periods of time when they are in use is not an attractive alternative because disengaging conventional hoists from a rail in a first room and engaging the hoist to a rail in another room is a cumbersome process, that often requires the use of special tools.

The rails for ceiling lifts are normally not continuous from one room to another. Moving a lifted person from between rooms that are not joined by a rail, e.g. through a door opening is very complicated or impossible with most conventional hoists. Conventional winches can usually only be operated in one orientation, i.e. the winch can either only be used in the “overhead” orientation where the winch housing is directly suspended from the rail with the spreader bar or other application suspended from the end of the extendable strap or cable, or the winch can only be used in the “upside down” orientation with the winch suspended from the rail via the extendable strap or cable whose free end is connected to the rail and the spreader bar is suspended from the winch housing. The optimum working position and orientation of the winch depends however on circumstances and none of the available prior art winches is flexible in this respect.

DISCLOSURE OF THE INVENTION

Against this background, it is an object of the present invention to provide a winch of the kind referred to initially, which overcomes or at least reduces the above mentioned problems by allowing it to operate in a plurality of orientations. This object is achieved in accordance with claim1by providing a winch of said kind with the housing having a second opening so that the traction member can be guided through the first opening or through the second opening.

Thus, it becomes possible to operate the winch in more orientations.

The second opening can be formed in a face of the housing that is substantially at right angles with the face of the housing in which the first opening is formed.

Thus, it becomes possible to operate the winch in four distinct orientations, namely:in the overhead orientation with the first attachment member connected to the rail, the traction member guided through the first opening in the housing and the free end of the traction member being connected to the load,in the upside down orientation with the first attachment member connected to the load, the traction member guided through the first opening in the housing and the free end of the traction member being connected to the rail,in the overhead orientation with the second attachment member connected to the rail, the traction member guided through the second opening in the housing and the free end of the traction member being connected to the load,in the upside down orientation with the second attachment member connected to the load, the traction member guided through the second opening in the housing and the free end of the traction member being connected to the rail.

The winch may comprise a second attachment member positioned substantially opposite to the second opening.

The first and/or second attachment member may form part of a quick release coupling system, preferably a system of the bayonet type.

The traction member may pass over a spring biased excenter shaft operatively connected with a switch that changes state when the load on the traction member exceeds a given threshold and thereby urges the excenter shaft to rotate against the spring bias.

It is another object of the present invention to provide a winch of the kind referred to initially, which is more flexible in use. This object is achieved in accordance with claim6by providing a winch of said kind in which the one or more attachment members form part of a quick release fastening system, preferably a system of the bayonet type.

Thus, the winch can be connected conveniently to rails, spreader bars, lifting straps and other suspension members.

Preferably, the one or more attachment members are provided with an electronic safety switch that is activated when a complementary part of the quick release fastening system is properly engaged with the attachment member concerned.

The free end of the traction member preferably comprises an attachment member, and the winch preferably comprises two attachment members.

It is another object of the present invention to provide a ceiling lift assembly of the kind referred to that is more flexible in use. This object is achieved in accordance with claim9by providing a winch assembly of said kind in which the attachment members are part of an interchangeably quick release coupling system. Thus the complete ceiling lift assembly can be quickly assembled and disassembled to move location, or to change operating position and orientation as different circumstances may require.

It is yet another object of the present invention to provide a winch of the kind referred to initially, with an improved mechanism for preventing operation of the electric motor when the traction member is not tensioned by a load. This object is achieved in accordance with claim13by providing a winch of said kind in which the traction member passes over a spring biased excenter shaft operatively connected with a switch that changes state when the load on the traction member exceeds a given threshold and thereby urges the excenter shaft to rotate against the spring bias.

The excenter shaft is preferably provided with an arm extending substantially perpendicular to the excenter shaft with the free end of the arm acting on the switch.

Further objects, features, advantages and properties of the mobile winch and use of the winch according to the invention will become apparent from the detailed description.

DETAILED DESCRIPTION

A ceiling lift1according to a preferred embodiment of the invention is illustrated inFIG. 1. The ceiling lift1incorporates an overhead rail2that is mounted adjacent to the ceiling. The rail2can be mounted on a lift structure or alternatively be mounted to the ceiling. A carriage (not shown) with a downward projection5is guided in the overhead rail2.

A discus shaped winch6is ready to be attached to the downward projection5at a connection point formed by first female seat16. The first female seat16and the downward projection5form a quick coupling of the bayonet type that will be described in more detail further below.

The housing of the winch6is formed by a first convex side panel20and a second convex side panel21that are interconnected by a rim22. Two recesses in the winch housing allow two diametrically opposite parts of the circumference of the rim22serve as handles23.

A lifting strap7projects from a first opening17(FIG. 5) in the first convex side panel20. A second opening19through which the strap7can leave the housing is provided in the rim22. The free end9of the lifting strap7is attached to a spreader bar10. The extremities of the spreader bar10are provided with hooks for attaching a sling or the like (not shown) holding the patient to be lifted.

FIG. 2shows the winch6with the first female seat16placed over the downward projection5.FIG. 3shows the winch secured by rotating it 90° relative to the orientation inFIG. 2about the vertical axis to engage the bayonet coupling. A second female seat18, disposed diametrically opposite to the second opening19can now be seen. The operating position of the winch6to the carriage in the rail as inFIGS. 1 to 3will in the following be referred to as “overhead mounted”.

FIG. 4shows the winch6from below. The free end of the strap7is connected to the projection5of the carriage in the rail2. The winch6is thus suspended from the strap7. The spreader bar10is directly connected to the winch6at the first female seat16. The operating position of the winch as inFIG. 4will in the following be referred to as “upside down mounted”.

FIG. 5shows the winch6from above with the first convex side panel20removed. The strap7is guided through the first opening17which is provided with a lug25on each side. Inside the housing the winch6is provided with a support structure with two parallel transverse plates26. A reel27for winding and unwinding the strap7is rotatably engaged between the transverse plates26. The reel27is connected to the output of a straight reduction gearing28which is in turn connected to the output of a worm drive29. The worm drive29is driven by a battery powered electric motor30. The electric motor30, the worm gear29and the reduction gearing28are arranged in a compartment31next to the support structure. The batteries (not shown) are received in a compartment32on the opposite side of the support structure, thus giving the winch6a substantially equal weight distribution. The strap7can be completely rolled up onto the reel and paid out through the second opening19, so that the winch may be used in another orientation. When the strap7extends though the first opening17the winch can be used in the “horizontal” position as illustrated inFIGS. 1 to 7. When the strap7extends though the second opening19the winch6can be used in the “vertical” position as illustrated inFIGS. 9 and 10. Each of these orientations has its advantages, and the optimum choice of operating position depends on circumstances.

FIG. 6shows a detail of the quick coupling system of the spreader bar10and the free end9of the strap7. A male part33the bayonet type quick coupling system extends upward from the spreader bar10. The free end9of the strap is provided with a seat35that incorporates the female part of the bayonet type quick coupling system. Connecting the spreader bar10to the free end9of the strap7is thus merely a matter of inserting the male part33into the female seat35and turning the seat35and the spreader bar 90° relative to one another. The quick coupling system is interchangeable throughout the ceiling lift, i.e. the male parts5and33fit to all female seats16,18and35.

FIGS. 7 to 10show the ceiling lift1in different operating positions and orientations. InFIG. 7the winch6is overhead mounted and the housing is in the horizontal orientation. This operating position gives a high maximum lifting height and the winch6itself is always far from the head of the patient. The winch6has however to be lifted up to the ceiling for mounting it with the first female seat16to the projection5of the carriage in the rail2.

InFIG. 8the winch6is mounted upside down and the housing is in the horizontal orientation. This operating position gives also a high maximum lifting height. The winch6can be mounted to the rail2by extending the strap7and engaging the female seat35on the free end9of the strap to the projection5of the carriage in the rail2. Then the winch6is activated to wind the strap7to lift the winch with the spreader bar10attached thereto. In this operating position the winch6itself is however always close to the head of the patient which could be experienced as an inconvenience. This operating position is particularly suitable for transfer between rooms that are not joined by a rail, as will be set out in detail below

InFIG. 9the winch6is overhead mounted and the housing is in a vertical orientation. This operating position gives a somewhat reduced maximum lifting height but the winch6itself is always far from the head of the patient. The winch6has however to be lifted up to the ceiling for mounting it with the first female seat16to the projection5of the carriage in the rail2.

InFIG. 10the winch6is upside down mounted and the housing is in a vertical orientation. This operating position gives a somewhat reduced maximum lifting height. The winch6can be mounted to the rail2by extending the strap7and engaging the female seat35on the free end9of the strap to the projection5of the carriage in the rail2. Then the winch6is activated to wind the strap7to lift the winch with the spreader bar10attached thereto. In this operating position the winch itself is always near to the head of the patient but since it extends mainly vertically this is usually not experienced as an inconvenience.

FIGS. 11 to 14illustrate step by step the procedure of passing though a door opening. The lift is to be transferred from the rail2to a second rail102in an adjacent room. InFIG. 11the operating position at the start of the procedure is the same as inFIG. 8. The free end9of the strap7is attached to the carriage in the rail2left to the wall34separating the two adjacent rooms. The door opening through which the lift with or without a patient should pass is below the wall34. A second non-windable strap107has one of its ends hooked to one of the a lugs25, and its other end connected to a carriage in the rail102. In the next step (FIG. 12) the strap7is carefully unwound and the load gradually transfers to strap107. Next (FIG. 13), the free end9of the strap7is detached from the carriage in rail2and reconnected to a carriage in rail102. Then, strap7is wound until the load transfers back to it and when the strap107is no longer carrying any load it is removed (FIG. 14) and the procedure is complete. The procedure is facilitated by the use of the quick coupling system.

FIGS. 15 to 17illustrate in detail the bayonet type quick coupling system according to a preferred embodiment of the invention and its operation. InFIG. 15the male part5,34provided with two diametrically opposite redial protrusions37is placed just in front of the female seat16,18,35for insertion. The female seat16,18,35is provided with a slot36suited for receiving the male part5,33in the orientation shown. To engage the coupling, the male part5,33is fully inserted into the slot36(FIG. 16) and turned 90° relative to the female seat16,18,35(FIG. 17) and then released. The female seat is provided with two abutment blocks38that allow rotation in only one direction when the male part5,34has just been inserted into the slot36. A notch39in the female seat for receiving the protrusions37extends to both sides of the slot36. The protrusions37are securely locked into the notch39when a load is applied to the male part5,34. In order to further improve safety, a micro switch40is arranged partially in the notch39such that it changes state when the protrusions37engage properly into the notch39. The micro switch40is connected to an electronic control unit60(FIG. 18) that controls operation of the electric motor30. When the switch is not actuated by a protrusion37the control unit prevents any winding or unwinding for safety reasons.

FIGS. 18 to 20show the details of the system in the winch6that prevents inadvertently winding or unwinding of the strap7when there is no load on the strap7.FIG. 18shows a cut open side view on the interior of the winch. The strap7extends from the reel27, passes over an excenter shaft50and leaves the winch6through the first opening17. The excenter shaft50is spring biased and provided with a radially extending arm51that actuates a micro switch55. Tension in the strap7urges the excenter shaft50to rotate against the spring bias and the radial arm rotates in unison with the excenter shaft. Thus, the switch changes state when a load above a preset threshold is applied to the strap7. The micro switch55is connected to the electronic control unit60. The electronic control unit60prevents winding and unwinding of the strap when no load on the strap7can be detected. Thus, inadvertently winding or unwinding an unloaded strap is avoided. The winch6is also provided with an excenter shaft50, radial arm51and micro switch55at the second opening19from which the strap can leave the winch (FIG.19,20).

Although the present invention has been described in detail for purpose of illustration, it is understood that such detail is solely for that purpose, and variations can be made therein by those skilled in the art without departing from the scope of the invention.

Thus, while the preferred embodiments of the devices and methods have been described in reference to the environment in which they were developed, they are merely illustrative of the principles of the inventions. Other embodiments and configurations may be devised without departing from the scope of the appended claims.