a ceiling lift 1 according to a preferred embodiment of the invention is illustrated in fig1 . the ceiling lift 1 incorporates an overhead rail 2 that is mounted adjacent to the ceiling . the rail 2 can be mounted on a lift structure or alternatively be mounted to the ceiling . a carriage ( not shown ) with a downward projection 5 is guided in the overhead rail 2 . a discus shaped winch 6 is ready to be attached to the downward projection 5 at a connection point formed by first female seat 16 . the first female seat 16 and the downward projection 5 form a quick coupling of the bayonet type that will be described in more detail further below . the housing of the winch 6 is formed by a first convex side panel 20 and a second convex side panel 21 that are interconnected by a rim 22 . two recesses in the winch housing allow two diametrically opposite parts of the circumference of the rim 22 serve as handles 23 . a lifting strap 7 projects from a first opening 17 ( fig5 ) in the first convex side panel 20 . a second opening 19 through which the strap 7 can leave the housing is provided in the rim 22 . the free end 9 of the lifting strap 7 is attached to a spreader bar 10 . the extremities of the spreader bar 10 are provided with hooks for attaching a sling or the like ( not shown ) holding the patient to be lifted . fig2 shows the winch 6 with the first female seat 16 placed over the downward projection 5 . fig3 shows the winch secured by rotating it 90 ° relative to the orientation in fig2 about the vertical axis to engage the bayonet coupling . a second female seat 18 , disposed diametrically opposite to the second opening 19 can now be seen . the operating position of the winch 6 to the carriage in the rail as in fig1 to 3 will in the following be referred to as “ overhead mounted ”. fig4 shows the winch 6 from below . the free end of the strap 7 is connected to the projection 5 of the carriage in the rail 2 . the winch 6 is thus suspended from the strap 7 . the spreader bar 10 is directly connected to the winch 6 at the first female seat 16 . the operating position of the winch as in fig4 will in the following be referred to as “ upside down mounted ”. fig5 shows the winch 6 from above with the first convex side panel 20 removed . the strap 7 is guided through the first opening 17 which is provided with a lug 25 on each side . inside the housing the winch 6 is provided with a support structure with two parallel transverse plates 26 . a reel 27 for winding and unwinding the strap 7 is rotably engaged between the transverse plates 26 . the reel 27 is connected to the output of a straight reduction gearing 28 which is in turn connected to the output of a worm drive 29 . the worm drive 29 is driven by an battery powered electric motor 30 . the electric motor 30 , the worm gear 29 and the reduction gearing 38 are arranged in a compartment 31 next to the support structure . the batteries ( not shown ) are received in a compartment 32 on the opposite side of the support structure , thus giving the winch 6 a substantially equal weight distribution . the strap 7 can be completely rolled up onto the reel and paid out through the second opening 19 , so that the winch may be used in another orientation . when the strap 7 extends though the first opening 17 the winch can be used in the “ horizontal ” position as illustrated in fig1 to 7 . when the strap 7 extends though the second opening 19 the winch 6 can be used in the “ vertical ” position as illustrated in fig9 and 10 . each of these orientations has its advantages , and the optimum choice of operating position depends on circumstances . fig6 shows a detail of the quick coupling system of the spreader bar 10 and the free end 9 of the strap 7 . a male part 33 the bayonet type quick coupling system extends upward from the spreader bar 10 . the free end 9 of the strap is provided with a seat 35 that incorporates the female part of the bayonet type quick coupling system . connecting the spreader bar 10 to the free end 9 of the strap 7 is thus merely a matter of inserting the male part 33 into the female seat 35 and turning the seat 35 and the spreader bar 90 ° relative to one another . the quick coupling system is interchangeable throughout the ceiling lift , i . e . the male parts 5 and 33 fit to all female seats 16 , 18 and 35 . fig7 to 10 show the ceiling lift 1 in different operating positions and orientations . in fig7 the winch 6 is overhead mounted and the housing is in the horizontal orientation . this operating position gives a high maximum lifting height and the winch 6 itself is always far from the head of the patient . the winch 6 has however to be lifted up to the ceiling for mounting it with the first female seat 16 to the projection 5 of the carriage in the rail 2 . in fig8 the winch 6 is mounted upside down and the housing is in the horizontal orientation . this operating position gives also a high maximum lifting height . the winch 6 can be mounted to the rail 2 by extending the strap 7 and engaging the female seat 35 on the free end 9 of the strap to the projection 5 of the carriage in the rail 2 . then the winch 6 is activated to wind the strap 7 to lift the winch with the spreader bar 10 attached thereto . in this operating position the winch 6 itself 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 in fig9 the winch 6 is overhead mounted and the housing is in a vertical orientation . this operating position gives a somewhat reduced maximum lifting height but the winch 6 itself is always far from the head of the patient . the winch 6 has however to be lifted up to the ceiling for mounting it with the first female seat 16 to the projection 5 of the carriage in the rail 2 . in fig1 the winch 6 is upside down mounted and the housing is in a vertical orientation . this operating position gives a somewhat reduced maximum lifting height . the winch 6 can be mounted to the rail 2 by extending the strap 7 and engaging the female seat 35 on the free end 9 of the strap to the projection 5 of the carriage in the rail 2 . then the winch 6 is activated to wind the strap 7 to lift the winch with the spreader bar 10 attached 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 . fig1 to 14 illustrate step by step the procedure of passing though a door opening . the lift is to be transferred from the rail 2 to a second rail 102 in an adjacent room . in fig1 the operating position at the start of the procedure is the same as in fig8 . the free end 9 of the strap 7 is attached to the carriage in the rail 2 left to the wall 34 separating the two adjacent rooms . the door opening through which the lift with or without a patient should pass is below the wall 34 . a second non - windable strap 107 has one of its ends hooked to one of the a lugs 25 , and its other end connected to a carriage in the rail 102 . in the next step ( fig1 ) the strap 7 is carefully unwound and the load gradually transfers to strap 107 . next ( fig1 ), the free end 9 of the strap 7 is detached from the carriage in rail 2 and reconnected to a carriage in rail 102 . then , strap 7 is wound until the load transfers back to it and when the strap 107 is no longer carrying any load it is removed ( fig1 ) and the procedure is complete . the procedure is facilitated by the use of the quick coupling system . fig1 to 17 illustrate in detail the bayonet type quick coupling system according to a preferred embodiment of the invention and its operation . in fig1 the male part 5 , 34 provided with two diametrically opposite redial protrusions 37 is placed just in front of the female seat 16 , 18 , 35 for insertion . the female seat 16 , 18 , 35 is provided with a slot 36 suited for receiving the male part 5 , 33 in the orientation shown . to engage the coupling , the male part 5 , 33 is fully inserted into the slot 36 ( fig1 ) and turned 90 ° relative to the female seat 16 , 18 , 35 ( fig1 ) and then released . the female seat is provided with two abutment blocks 38 that allow rotation in only one direction when the male part 5 , 34 has just been inserted into the slot 36 . a notch 39 in the female seat for receiving the protrusions 37 extends to both sides of the slot 36 . the protrusions 37 are securely locked into the notch 39 when a load is applied to the male part 5 , 34 . in order to further improve safety , a micro switch 40 is arranged partially in the notch 39 such that it changes state when the protrusions 37 engage properly into the notch 39 . the micro switch 40 is connected to an electronic control unit 60 ( fig1 ) that controls operation of the electric motor 30 . when the switch is not actuated by a protrusion 37 the control unit prevents any winding or unwinding for safety reasons . fig1 to 20 show the details of the system in the winch 6 that prevents inadvertedly winding or unwinding of the strap 7 when there is no load on the strap 7 . fig1 shows a cut open side view on the interior of the winch . the strap 7 extends from the reel 27 , passes over an excenter shaft 50 and leaves the winch 6 through the first opening 17 . the excenter shaft 50 is spring biased and provided with a radially extending arm 51 that actuates a micro switch 55 . tension in the strap 7 urges the excenter shaft 50 to 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 strap 7 . the micro switch 55 is connected to the electronic control unit 60 . the electronic control unit 60 prevents winding and unwinding of the strap when no load on the strap 7 can be detected . thus , inadvertedly winding or unwinding an unloaded strap is avoided . the winch 6 is also provided with an excenter shaft 50 , radial arm 51 and micro switch 55 at the second opening 19 from which the strap can leave the winch ( fig1 , 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 . ? fig5 shows the winch 6 from above with the first convex side panel 20 removed . the strap 7 is guided through the first opening 17 which is provided with a lug 25 on each side . inside the housing the winch 6 is provided with a support structure with two parallel transverse plates 26 . a reel 27 for winding and unwinding the strap 7 is rotatably rotably engaged between the transverse plates 26 . the reel 27 is connected to the output of a straight reduction gearing 28 which is in turn connected to the output of a worm drive 29 . the worm drive 29 is driven by a an battery powered electric motor 30 . the electric motor 30 , the worm gear 29 and the reduction gearing 28 are arranged in a compartment 31 next to the support structure . the batteries ( not shown ) are received in a compartment 32 on the opposite side of the support structure , thus giving the winch 6 a substantially equal weight distribution . the strap 7 can be completely rolled up onto the reel and paid out through the second opening 19 , so that the winch may be used in another orientation . when the strap 7 extends though the first opening 17 the winch can be used in the “ horizontal ” position as illustrated in fig1 to 7 . when the strap 7 extends though the second opening 19 the winch 6 can be used in the “ vertical ” position as illustrated in fig9 and 10 . each of these orientations has its advantages , and the optimum choice of operating position depends on circumstances . please replace the paragraph starting at page 11 , line 30 , with the following paragraph : fig1 to 20 show the details of the system in the winch 6 that prevents inadvertently winding or unwinding of the strap 7 when there is no load on the strap 7 . fig1 shows a cut open side view on the interior of the winch . the strap 7 extends from the reel 27 , passes over an excenter shaft 50 and leaves the winch 6 through the first opening 17 . the excenter shaft 50 is spring biased and provided with a radially extending arm 51 that actuates a micro switch 55 . tension in the strap 7 urges the excenter shaft 50 to 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 strap 7 . the micro switch 55 is connected to the electronic control unit 60 . the electronic control unit 60 prevents winding and unwinding of the strap when no load on the strap 7 can be detected . thus , inadvertently winding or unwinding an unloaded strap is avoided . the winch 6 is also provided with an excenter shaft 50 , radial arm 51 and micro switch 55 at the second opening 19 from which the strap can leave the winch ( fig1 , 20 ).
the invention relates to a winch for raising and lowering persons , of the type that comprises a housing with an attachment member , an electric motor driving a reel , a lifting strap connected to the reel for winding and unwinding the lifting strap whereby the lifting strap is guided through one of two openings formed in the housing .