Abstract:
A patient lifting and transfer device is shown which includes a pair of vertical columns having a horizontal bar connected between the two columns. There is provided a mobile support that is rotatively mounted to the lower portion of each vertical column. Each mobile support is elongated and rotatable from a first position where the elongated mobile support extends generally perpendicular to the horizontal bar to a second position where the mobile supports extend generally parallel to the horizontal bar. In the second position, the patient lifting and transport device is relatively narrow and can be moved through close quarters and also stored in relatively small areas.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority under 35 U.S.C. §119(e) from the following U.S. provisional application: Application Ser. No. 61/373,066 filed on Aug. 12, 2010. That application is incorporated in its entirety by reference herein. 
     FIELD OF THE INVENTION 
     The present invention relates to lifting and moving patients. The present invention also entails a patient lifting and transfer device comprising a pair of vertical columns having a horizontal bar connected between the two columns. In addition, there is provided a mobile support that is rotatably mounted to the lower portion of each vertical column. Each mobile support is elongated and rotatable from a first position where the elongated mobile support extends generally perpendicular to the horizontal bar to a second position where the mobile supports extend generally parallel to the horizontal bar. In the second position, the patient lifting and transport device is relatively narrow and can be moved through close quarters and also stored in relatively small areas. 
     BACKGROUND 
     Health care workers and their patients face problems related to lifting and moving non-ambulatory patients. Health care workers face possibilities of injuries to themselves in lifting such patients. Patients as well are often subjected to potential injuries in the process of being lifted and moved. Additionally, extant devices and systems for assisting or facilitating the lifting and moving of such patients often subject the patient to disconcerting fear as well as humiliation. Being, for example, slung under a hoist with lifting cranks or motors suspended overhead is often a source of fear. Moreover, such extant devices often include configurations that are ungainly to use, difficult to move through doorways and negotiate past obstacles, and bulky to store. 
     There is a need for a patient lifting device that respects the sensibilities of patients, provides a stable and secure lifting arrangement, is easy to maneuver and operate, and is capable of being efficiently stored. 
     SUMMARY OF THE INVENTION 
     The present invention entails a device for lifting and moving a patient with respect to a bed, wheelchair, table, or the floor. The patient lift device includes a generally arched superstructure supported on mobile trolleys. The superstructure includes a lifting beam supported by a pair of variable height columns. The lifting beam carries a suspensory trolley for suspending a sling holding a patient. The suspensory trolley is movable along the beam to laterally position the patient while the variable height columns provide vertical patient movement. 
     The present invention also entails a device for lifting and moving a patient that provides an upper patient support structure and a driver system for vertically moving the patient. The upper patient support structure is configured to support the patient away from the driver system. 
     The present invention further entails a device for lifting and moving a patient that provides an upper patient support structure and a lifting driver system, which are supported on movable transport trolleys that enable unrestricted movement of the device about a generally horizontal support surface. The transport trolleys are pivotable about vertical axes to permit changing the footprint of the device for storage and transport. 
     The present invention provides a method of lifting and transporting a patient with a patient lift device, the method including extending an arched structure over the patient. The method further includes securing the patient to an upper portion of the arched structure and raising the arched structure to lift the patient. The method further includes disposing the patient away from lift driving assemblies comprised in the patient lift device while lifting and moving the patient. Moving the patient includes transporting the arched structure on transport trolleys comprised in the patient lift device. 
     The present invention also entails a patient lifting and transfer device comprising a pair of vertical columns having a horizontal bar connected between the two columns. In addition, there is provided a mobile support that is rotatably mounted to the lower portion of each vertical column. Each mobile support is elongated and rotatable from a first position where the elongated mobile support extends generally perpendicular to the horizontal bar to a second position where the mobile supports extend generally parallel to the horizontal bar. In the second position, the patient lifting and transport device is relatively narrow and can be moved through close quarters and also stored in relatively small areas. 
     Other objects and advantages of the present invention will become apparent and obvious from a study of the following description and the accompanying drawings which are merely illustrative of such invention 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of an embodiment of the patient lift device. 
         FIG. 2  is a fragmentary perspective view of upper portion of an embodiment of the patient lift device. 
         FIG. 3  is a fragmentary cross-sectional view of a support column, transport trolley assembly, and lifting drive assembly of an embodiment of the patient lift device. 
         FIG. 4  is a fragmentary perspective view of an upper portion of an embodiment of the patient lift device. 
         FIG. 5  is a perspective view of an alternate embodiment of the patient lift device. 
         FIG. 6  is a perspective view of an exemplary linear actuator utilized in the embodiment of  FIG. 5 . 
         FIG. 7  is a fragmentary perspective view of an upper portion of the embodiment of  FIG. 5 . 
         FIG. 8  is a fragmentary perspective view of a lower portion of the patient lift device. 
     
    
    
     DESCRIPTION OF THE INVENTION 
     The present invention entails a patient lift device, indicated generally by the numeral  100  and illustrated generally in  FIG. 1 . Patient lift device  100  comprises an arched superstructure that is movable over a generally horizontal surface. In particular, the patient lift device  100  comprises an upper support structure  10  interconnected with and supported by a pair of support or vertical lift columns  20 . Each support column  20  rests upon a transport trolley  30 . Upper support structure  10  includes a cross beam or bar  12 , with each end thereof supported on a respective one of the support columns  20 . Each support column  20  is connected to a lifting drive assembly or lift actuator  40 . Riding on cross beam  12  is a suspensory trolley  60  from which a patient may be suspended as will be described herein. Once suspended, the patient may be lifted and laterally moved by actuating the drive assemblies  40  to raise cross beam  12 . 
     Each transport trolley  30  includes a generally elongated carriage  32  supported by a series of casters  34  of common design mounted thereunder as can be further appreciated from  FIG. 2 . A base flange  22  of each support column  20  rests on the respective carriage  32 . Each transport trolley  30  is journalled to the corresponding support column  20  by a transport trolley pivot assembly  50  and by engagement of a lower portion of the column with carriage  32 . Journalled connection of transport trolley  30  with support column  20  enables pivoting or turning transport trolley  30  about a generally vertical axis of column  20  and locking the trolley in either of two angular relationships with cross beam  12 . For example, each transport trolley  30  may be pivoted or swiveled to and locked in a position such that elongated carriage  32  is generally normal to cross beam  12  to provide stable support for an operable mode lifting configuration of patient lifting device  100 . As another example, each transport trolley  30  may be swiveled and locked in a position so that elongated carriage  32  is generally parallel with cross beam  12  to provide for compact transport and storage mode of patient lift device  100  while not in use. It is appreciated that transport trolley  30  may be locked in various other angular positions as well. 
     Trolley pivot assembly  50  includes handles  56 , shown at least in  FIG. 2 , which may be gripped by a person operating or moving patient lift device  100  in order to turn or swivel the trolley. Locking of transport trolley in a particular angular position may be provided by any of a number of well known means. For example, it is well known that portions of handles  56  may be threaded through collar  52  and configured to seat against support column  20 . In accordance with well known design practice, depressions or flats may be provided on the outer surface of column  20  to provide for detented registering in pre-defined angular orientations of transport trolley such as normal to cross beam  12  for operating patient lift device  100  to lift a patient safely or parallel to the cross beam for device transport and storage when not in use. 
     As can be appreciated at least from  FIG. 2 , casters  34  are arrayed so as to provide stable support of patient lift device  100 . In the illustrated embodiment, casters  34  are arrayed in a pattern where one of the casters is affixed to a lateral extension  32 A of undercarriage  32  so that this particular caster is side shifted from the remaining four casters. This arrangement provides for stability of patient lift device  100  when configured for device transport and storage. Moreover, such an arrangement of casters  34  provides additional stability to patient lift device  100  when in the operable, patient lifting mode as also described above. At least one of the casters  34  of each transport trolley  30  is equipped with a lock  34 A of common design for preventing unwanted movement of patient lift device  100 . 
     It is appreciated that carriage  32  of transport trolley  30  may be configured as a generally elongated plate or tube formed of stainless steel or other ferrous metal protected from corrosion. Carriage  30  may be formed from plate or tube stock, and casters  34  may be mounted directly underneath the plate as illustrated in  FIG. 2 . Alternatively, for example, each caster  34  may be mounted to an intervening bracket that can be mounted to the plate of carriage  30  as shown in  FIG. 3  where a portion of the plate is removed. 
     In one embodiment, a lifting drive assembly  40  is supported at a lower end of each support column  20 . The lifting drive assemblies  40  are configured to movably position upper support structure  10  vertically. Lifting drive assembly  40  is of a commercially-available linear actuator design that comprises a ball screw actuator powered by a servomotor  42 . See  FIG. 2 . Electrical operation controls of well known design may be deployed to provide actuation control of lifting drive assemblies  40 . Lifting drive assemblies  40  are deployed in patient lift device  100  to raise and lower crossbeam  12  and to raise and lower a patient connected to the cross beam as will be described in more detail hereinafter. As may be appreciated from  FIG. 3 , assembly  40  further comprises a collar  44  threadingly engaged with a threaded screw shaft  46  coupled to a telescoping portion  48  of support column  20 . Rotating shaft  46  in one direction by actuation of servomotor  42  drives telescoping portion  48  in an upward direction to raise cross beam  12  to lift a patient supported thereby. Counter-rotation of shaft  46  correspondingly moves cross beam  12  downward to lower a patient thereby supported. 
     Turning now to the upper portion of patient lift device  100  and referring more particularly to  FIG. 4 , it is appreciated that one of the telescoping members  22  is secured within an opening on each end of cross beam  12 . Further, with the aid of  FIG. 3  it is appreciated that when cross beam  12  is in its lowest position, the cross beam rests against upper ends of support columns  20 . When cross beam  12  is elevated, as described here above, the cross beam is supported by telescoping members  22 . 
     As configured in the embodiment of  FIGS. 1-4 , it is appreciated that lifting drive assemblies  40  are disposed downwardly and horizontally away from the patient. This arrangement provides for avoidance of negative reactions by the patient to any noise or movement of the assemblies. 
     It is appreciated that other configurations of linear actuators may be employed in patient lift device  100  of the present invention. For example in the embodiment illustrated in  FIGS. 5-7 , patient lift device  100  provides a differently disposed, compact lifting drive assembly  80  in the alternative to assembly  40  of the embodiment illustrated in  FIGS. 1-4 . Lifting drive assembly  80  comprises a linear actuator  82 , an example of which includes Actuator LA36 manufactured by Linak (http://www.linak.com/) illustrated in  FIG. 6 . Actuator  82  includes a housing  82 A with a mounting stud  82 B for securing the actuator to a portion of a structure to be moved by the actuator. As can be appreciated by an ordinarily skilled mechanic, mounting stud  82 B can be secured to cross beam  12  by any of a number of well known methods. Actuator  82  also includes a rod guide  82 C and a rod  82 D. Rod  82 D is extended and retracted by the action of a permanent magnet motor comprised in actuator  82 . The ordinarily skilled mechanic can likewise appreciate that rod  82 D may be connected to one of the support columns  20  by any of a number of well known methods such that when the rod extends, cross beam  12  is raised and when the rod retracts the cross beam is lowered. As shown in  FIG. 7 , a portion of rod guide  82 C may extend within an upper portion of support  20 , and rod  82 D may be secured interiorly to the support (not shown). It is appreciated that this kind of compact actuator and its placement horizontally away from the patient provides for avoidance of negative reactions by the patient to any noise or movement of the assemblies. 
     Illustrated in  FIG. 8  is an example of an alternative transport trolley locking device  90  to enable foot-operated unlocking of transport trolley  30  for swiveling between operative and storage modes. Locking device  90  includes a foot pedal  92  connected to a locking pawl  94  that extends into a slot in base flange  22  of support column  20 . In one embodiment, pawl  94  may be spring loaded using well known methods in a locked position such that the pawl interferes with a surface on carriage  32  to lock the carriage to the base plate. Depressing foot pedal  92  disengages locking pawl  94  from carriage  32  to permit swiveling of transport trolley  30 . While the illustration of  FIG. 8  shows alternative transport trolley locking device  90  in the context of the embodiment of patient lift device  100  illustrated in  FIGS. 5-7 , it is appreciated that the alternative locking device can be deployed on base flanges  22  of the embodiment of  FIG. 3 . 
     Turning more particularly to suspensory trolley  60 , as here before mentioned, the suspensory trolley rides on cross beam  12  and serves to suspend a patient from the cross beam. Suspensory trolley  60  comprises a yoke assembly  64  that receives cross beam  12  and is movable along the length of the cross beam. Assembly  64  comprises a pair of spaced apart side plates  64 C supporting corresponding ends of upper rollers  64 A and lower roller  64 B. It is appreciated that assembly  64  forms an opening shaped and sized to receive the cross beam  12  and permit movement of suspensory trolley  60  along the cross beam so as to move a suspended patient from side to side. See  FIG. 4 . 
     In one embodiment, a load sensor  66  may be connected to suspensory trolley  60  to enable weighing a patient suspended there from. Load sensor  66  is of know commercial design that may, for example, include an active element  66 A connected to attachment rings  66 B. Upper attachment ring  66 B is secured to suspensory trolley  60  by engagement with pin  64 D as shown in  FIG. 4 . Lower attachment ring  66 B is engaged with link  68  which is secured to the patient sling (not shown). By well known means not shown, sensor  66  is interfaced with a display module  62  that is mounted on the suspensory trolley, the use of which permits observation of the weight of the lifted patient. Those of ordinary skill will appreciate that the interfacing means may commonly include the capability of tare weight adjustment to compensate for the weights of suspended items other than the patient. 
     Deployed with patient lift device  100  are one or more obstruction sensors  70  of common design configured to signal and prevent interference of the upper portion of the device with obstructions such as light fixtures or other overhead structures that may be found in a hospital room, treatment, room, or any other environment in which the device is utilized to lift a patient. A sensor  70  may, for example, be a contact device which is activated by a feeler contacting with an obstruction in the course of a patient being lifted. A sensor  70 , as another example, may be a proximity device that senses an approach to an obstruction by interruption of a light beam or by reflected radiation. Such sensors may be deployed about the upper portion of device  100  and electronically incorporated within well known controls (not shown) for controlling lifting drive assemblies  40  to safely stop lifting action in the event of an obstruction. 
     Patient lifting device  100  may be utilized to lift a non-ambulatory patient or to lift and move the patient from a bed, a wheel chair, an examination or treatment table or the floor. It is sufficient to describe the processes of use of device  100  in the context of lifting a patient from a bed to, for example, permit changing bed linens. To use device  100 , the device may be moved from storage where it would have been configured with transport trolley assemblies  30  rotated into alignment with cross beam  12 . Prior to positioning device  100  for operation, transport trolley assemblies  30  are swiveled into positions generally normal to cross beam  12  and locked into position. Device  100  is them rolled in to position such that the device straddles the bed with one of the support columns  20  on one side of the bed and the other support column on the other side of the bed and cross beam  12  is disposed over the patient. The patient is recumbent on a sling of well known design, with supporting band having been slid under the patient. Suspensory trolley  60  may then be moved to laterally position the trolley over the patient. The sling may then be connected to link  68  using, for example, a four-point carry or lift bar of well known design. Such arrangements are well known and operable to provide stable and secure patient engagement for lifting. 
     After the patient sling is secured to link  68 , lifting drive assemblies  40  may be actuated to lift the patient to the desired height, for example, to clear the upper surfaces of the bed. If desired, the patient may be gently shifted to one side or the other by manually pushing suspensory trolley  60  in one direction or the other. Further, and if desired, device  100 , with the patient suspended thereby, may be moved away from the bed by manually pushing or pulling and moving it on casters  34  of transport trolleys  30 . 
     While the patient is thusly suspended by an embodiment of device  100  that incorporates sensor  66  and display module  62 , the weight of the patient may be observed and recorded as needed. Such weighing is of utility in many patient care situations. 
     After the bed is prepared to again receive the patient, device  100  may be repositioned relative to the bed in a manner similar to its initial positioning as described above. As needed, the suspended patient may be shifted laterally by moving suspensory trolley  60  as described above. Lifting drive assemblies  40  may then be actuated to gently lower the patient into the bed after which the sling may be disconnected from link  68 . Device  100  may then be rolled away from the bed and moved for use elsewhere or for storage. In the course of movement and for storage, transport trolleys  30  may be swiveled and locked in the transport or storage mode to facilitate movement of device  100  through doors and to enable compact storage. 
     The present invention may, of course, be carried out in other specific ways than those herein set forth without departing from the scope and the essential characteristics of the invention. The present embodiments are therefore to be construed in all aspects as illustrative and not restrictive.