Abstract:
A transfer device transfers an individual from a bed to an adjacent support surface or vice versa and includes a mobile unit defined by a base and an upstanding structure having lower and upper end portions respectively adjacent to and remote from the base. A lower drive pulley and an upper idler pulley are located respectively adjacent to and remote from the base. A motor rotates the lower drive pulleys to wind thereupon a cable at least partially entrained upon the upper idler pulley. Clamps releasably connect the cable to a slide interposed between an individual and a bed or an adjacent support surface upon which an individual is reposed whereby upon operation of the motor, the slide with an individual thereon is pulled from a bed to an associated adjacent support surface or vice versa.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to solving ongoing and persistent problems encountered by care-givers when transferring a bed-ridden person from his/her bed to and from another support, such as a gurney, a bath/toilet-type platform, etc., or vice versa. The effort required by a care-giver to physically move a bed-ridden person is substantial and many times results in injury, particularly lower back injury, to the care-giver. Elderly, weak and/or essentially immobile persons who are being treated in hospitals or reside in high maintenance nursing homes are continually transferred between a bed and a gurney or a bed and a wheelchair for a multitude of purposes, such as treatment in operating theaters, therapy rooms, x-ray rooms, etc. Absent effective mechanical assistance, as is presently the case, a care-giver must necessarily physically lift, slide and/or carry the bed-ridden person from his/her bed to and from a gurney, a wheelchair, a toilet chair, a shower chair or some other type of bathroom function device which is highly strenuous. Equally strenuous, particularly with relatively heavy patients, is the seemingly simple task of moving a patient horizontally between two supporting surfaces at substantially identical levels, such as an adjacent bed and gurney. An immobile person lacking physical strength is dead weight and, whether pushed or pulled, many care-givers/attendants barely have enough strength to move such a person. Equally dangerous is the application of physical pushing and/or pulling forces to the bed-ridden person which can, in and of itself, cause physical pain and/or damage, particularly when the bed-ridden person is old, may have brittle bones, etc. Therefore, the necessity of a transfer device which is both care-giver and patient friendly is extremely desirable, particularly if made available to hospitals, nursing homes and the like at a reasonable price. 
         [0002]    Mechanical transfer devices for transferring bed-ridden persons are available to care-givers but, for the most part, these require considerable strength to manually operate the transfer device. At the very least handles and/or levers must be manipulated to elevate a bed-ridden person and thereafter considerable strength is required to push and/or pull the bed-ridden person, while elevated, to a particular location, such as swinging the bed-ridden person above a wheelchair, a toilet chair, a gurney or the like. One such transfer device is disclosed in a family of patents in the name of Graham L. Hodgetts and assigned to Barton Medical Corporation of Austin, Tex., namely, U.S. Pat. Nos. 5,697,109; 5,819,339; 5,996,144; 6,289,533 and 6,507,963. All of the latter patents disclose a patient transfer device for transferring a patient from a bed to a gurney or from the gurney to the bed utilizing a conveyor attached to both the bed and the gurney. Each conveyor is relatively complex and necessitates being welded to the gurney and/or to the bed frame or being otherwise fastened thereto. A bed sheet is attached to a roller of the conveyor, but as opposed to a standard bed sheet, the bed sheet is necessarily at least twice the width of the bed to enable a patient lying upon one half of the bed sheet to be pulled from the bed or the gurney by rotating the roller, to which the bed sheet is attached, by an associated handle. An obvious disadvantage of this patient transfer device is the necessity of either securing a conveyor to every bed or to every gurney, which is extremely expensive and obviously still involves physical strength to rotate the handle and pull the patient to or from the bed/gurney. The latter patents recognize the seriousness of the problem presented to the healthcare industry, but the patient transfer device of the latter patents is at best an extremely inadequate effort aimed toward a solution of the problem at a high cost per patient transfer device. 
       BRIEF SUMMARY OF THE INVENTION 
       [0003]    In accordance with the present invention, a transfer device for moving a bed-ridden patient to and from a bed and/or a gurney or the like includes a self-sustained mobile unit defined by a platform or base mounted on wheels or castors which carries an upstanding structure, preferably in the form of a pair of vertical supports, each having an upper and a lower end carrying respective idler and drive pulleys. Flexible cables are entrained about the pulleys and upper ends of the cables are connected to a pull bar which is in turn connected by attachment clips to a slide sheet which can be a conventional bed sheet but preferably is a sheet of material having an extremely low coefficient of friction at least upon a lower surface thereof which slides upon/across a bed or gurney mattress, a gurney upper support surface, or the like. A lower end of each of the cables is connected to a driven shaft which is in turn driven by a reversible drive motor and a reduction gearing to impart sufficient power to pull the slide sheet and the patient thereupon readily easily from a bed to a gurney or vice versa absent any physical effort on the part of the care-giver/attendant. 
         [0004]    The vertical supports are located toward an end of the base or platform remote from a forward end thereof which is located a considerable distance beneath a gurney, for example, onto which a patient is to be moved from an adjacent bed. The vertical supports include pads which bear against the gurney, and as the patient is being slid from the bed to the gurney, any turning moment which might otherwise tend to tilt or cock the transfer device is resisted by the location of the forward end of the platform well beneath the gurney and the contact between the gurney and the vertical supports. This assures that the driving force of the electric motor operating through the reduction gearing and imparted to the slide sheet is efficiently utilized as a pulling force, as opposed to a moment-creating force. Moment-creating forces are also reduced by constructing the vertical supports so as to be vertically adjustable to generate pulling forces applied to the slide sheet which are substantially horizontal and preferably slightly upwardly inclined to the horizontal to maximize the pulling forces applied to the slide sheet and minimize the creation of turning moment forces. 
         [0005]    Conventional clamping mechanisms may be associated with the vertical supports for clamping the same to the bed/gurney, etc. to assure efficient patient transfer operations, as might be required if a patient is relatively heavy (200-300 pounds). 
         [0006]    A control system for operating the reversing motor preferably includes a hand-held remote control unit provided with appropriate on/off and directional switches and a switch to control a solenoid for engaging a clutch to impart desired directional rotation to the lower driven pulleys which are in turn connected to a single lower driven shaft. Override/safety proximity switches are also utilized to preclude unintended transfer motion of the slide sheet to thereby prevent patient/caretaker injury. 
         [0007]    With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claims and the several views illustrated in the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a fragmentary perspective view of a novel patient transfer device of the present invention, and illustrates a base carrying at a rear end portion thereof a pair of adjustable vertical supports which in turn carry idler pulleys at upper ends about which are entrained pull cables connected to a pull bar which is in turn connected to a slide sheet upon which a patient lies incident to the performance of a patient transfer operation through the energization of an associated reversible electric motor, reduction gearing, a clutch and a belt drive for rotating a pair of driven pulleys to which the pull cables are connected. 
           [0009]      FIG. 2  is a side elevational view of the patient transfer device, and illustrates the same associated with a bed upon which rests the slide sheet, a patient upon the slide sheet, a gurney and the patient transfer device incident to being moved to the position shown in  FIG. 3 . 
           [0010]      FIG. 3  is a side elevational view, and illustrates the patient transfer device positioned incident to patient transfer with transfer bar clamps connected to an edge of the slide sheet. 
           [0011]      FIG. 4  is a side elevational view, and illustrates the slide sheet with a patient thereon being transferred from the bed to the gurney through appropriate energization of the electric motor and the various components associated therewith including the lower pair of driven pulleys, the cables connected thereto, the upper idler pulleys, the transfer bar and the slide sheet clamps. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0012]    A novel patient transfer device constructed in accordance with this invention is illustrated in  FIG. 1  of the drawings and is generally designated by the reference numeral  10 . 
         [0013]    The patient transfer device  10  is adapted to transfer an individual, patient, bed-ridden person P ( FIGS. 2 through 4 ) or the like from a conventional bed B to a gurney G or vice versa in a manner to be described more fully hereinafter. 
         [0014]    The patient transfer device  10  includes a mobile unit defined by platform or a base  11  and an upstanding vertical structure  12 . 
         [0015]    The base  11  is substantially elongated and includes a pair of substantially parallel high strength steel longitudinal tubes  13 ,  14  having upwardly offset forward ends or end portions  15 ,  16  and similar upwardly offset rear ends or end portions  17 ,  18 , respectively. Lockable/unlockable castors or wheels  20  of a conventional construction are conventionally attached to the forward end portions  15 ,  16  and the rear end portions  17 ,  18  of the base  11 . A pair of high strength steel transverse tubes  21 ,  22  ( FIG. 1 ) are in parallel spaced relationship to each other and opposite ends (unnumbered) are welded to the longitudinal tubes  13 ,  14 . A steel plate  23  bridges the transverse tubes  21 ,  22  and is welded thereto. 
         [0016]    The plate  23  provides a support for a number of drive components suitably conventionally secured thereto including a drive mechanism or drive means  25  ( FIG. 1 ) defined by an electric reversible motor  26  having an output shaft (not shown) connected to reduction gearing (not shown) located in a conventional step-down gear box  27  having an output shaft (not shown) connected to a conventional clutch defined by clutch bodies  28 ,  29  having clutch faces (unnumbered) in opposing relationship to each other. The clutch body  29  carries a toothed drive gear  31  carried by a shaft (not shown) supported for rotation in a conventional bearing (not shown) in one or more bearing supports  33 , only one of which is shown, carried by the platform  23 . A conventional solenoid  34  selectively reciprocates a shaft or plunger  35  axially opposing the shaft (not shown) connected to the clutch body  29  to move the same into and out of engagement with the clutch body  28  to respectively rotate and terminate rotation of the toothed drive gear or sprocket  31  about which is entrained a high strength plastic toothed drive belt or chain  37 . A housing  40  carried by the platform  23  is supplied 115 volt A/C power input via a power cord  41  which can be connected to a conventional electrical outlet. The 115 volt A/C input controls the electric motor  26  via a hand wired push-button switch control SC or a remote control RC and an associated transformer (not shown) steps-down the 115 volt A/C to 24 volt D/C to operate the solenoid  34  and associated relays and switches which will be described hereinafter. 
         [0017]    The upstanding vertical structure  12  includes a pair of substantially parallel vertical telescopic tubes  51 ,  52  defined by respective lower inner tubes  53 ,  54  each having pairs of vertically spaced aligned apertures  55  and outer upper tubes  56 ,  58 , respectively. Each of the outer upper tubes  56 ,  58  includes pairs of vertically spaced openings  57  which can be selectively aligned with the openings  55  for receipt therein of an associated pin  60  to maintain the telescopic tubes  51 ,  52  at any one of a plurality of different vertical heights. Lower end portions (unnumbered) of the lower inner tubes  53 ,  54  are welded to the respective longitudinal tubes  13 ,  14  of the base  11  and carry at lower ends thereof journal blocks  42 ,  43  housing conventional bearings. A central bearing block  44  carrying a bearing is connected to the plate  23 . A driven shaft  45  carries a toothed gear or sprocket  46  about which is entrained the toothed drive belt or chain  37 . Opposite ends of the driven shaft  45  are journaled in the bearings of the journal blocks  42 ,  43  and  46 , and inboard of each bearing or journal block  42 ,  43  are lower driven pulleys  47 ,  48 , respectively, keyed to the driven shaft  45 . 
         [0018]    Upper idler pulleys  67 ,  68  are conventionally secured for free rotation adjacent upper ends (unnumbered) of the respective upper tubular supports  56 ,  58 , respectively, which are secured to each other by a steel tubular transverse brace  59  welded thereto. 
         [0019]    Means in the form of elongated elements, such as relatively strong nylon ropes or cables  72 ,  73  are connected to the lower drive pulleys  47 ,  48 , respectively, and are partially entrained about the respective upper idler pulleys  67 ,  68 . Upper terminal ends (unnumbered) of the respective cables or ropes  72 ,  73  are connected to a pull bar  80  to which is also connected four identical short resilient elongated members, such as nylon ropes or cables  81  to ends of which are attached a conventional universal joint or connector  82  and a conventional clamp  83  for gripping an edge E of a slide sheet SS which may be a conventional bed sheet but is preferably a sheet of a two-ply construction including an upper textile material surface TMS, such as cotton, and a lower low friction surface LLFS (polymeric/copolymeric material, Teflon®, for example). 
         [0020]    Identical elongated cushions or pads  85  are adhesively bonded to each of the upper tubes  56 ,  58 , and each of the upper tubes  56 ,  58  also carries conventional clamping means  87 , such as conventional Velcro® straps. 
         [0021]    The patient transfer device  10  preferably is enclosed in a housing (not shown) which precludes access to most of the moving parts to prevent damage thereto and/or damage/harm/injury to patients and/or attendants. For example, the pulleys  67 ,  68 ;  47 ,  48  and the runs of the pulley belts  72 ,  73  therebetween are entirely enclosed, as is the entirety of the shaft  45 , all of the components resting upon the plate  23 , and the driven belt or chain  37 . Preferably, a vertically upstanding housing portion covering the lower ends of the belts  72 ,  73  is rigidly secured to the base  11  while upper housing portions are telescopic relative thereto and include access regions for accessing the openings/holes  55 ,  57  and manipulating the pin  60  associated therewith. Therefore, the only powered components exposed beyond the housing are the upper reaches of the pulley belt  72 ,  73 , the pull bar  80 , the ropes  81 , the universal joints  82  and the clamps  83 . 
       Patient Transfer Device Operation 
       [0022]    Reference is first made to  FIG. 2  of the drawings which illustrates the patient or bed-ridden person P lying upon a conventional sheet or preferably the slide sheet SS of the present invention which is readily and easily positioned between the patient P and an upper surface of a conventional sheet (unnumbered) covering a mattress M of the bed B. The slide sheet SS is placed beneath the patient by a care-giver/attendant rolling the patient P from one side to the other while appropriately folding, unfolding and/or manipulating the slide sheet SS in a conventional manner which is relatively effortless, particularly as compared to pulling and/or lifting and transporting the patient P to the gurney G. The gurney G is positioned adjacent the bed B and, if desired, may be at least temporarily secured thereto by conventional Velcro® straps VS. The patient transfer device  10  is then rolled from the position shown in  FIG. 2  to the position shown in  FIG. 3  after which the support structure  12  can be vertically adjusted utilizing the pairs of openings  55 ,  57  and the pins  60  to position the cushions  85  against a mattress Mg of the gurney G. The Velcro® straps  87  may then be secured to legs L of the gurney and the clamps  83  are secured to the edge E ( FIG. 1 ) of the slide sheet SS. Since the solenoid  34  ( FIG. 1 ) is not energized, the clutch  28 ,  29  is not engaged and the care-giver can grasp the pull bar  57  and easily pull the same from the position shown in  FIG. 2  to the position shown in  FIG. 3  to unwind the nylon cables  72 ,  73  from the drive pulleys  47 ,  48  incident to applying the clamps  83  to the edge E of the slide sheet SS. By depressing the correct power/direction of rotation/solenoid buttons of the hard wired push-button switch, control SC or remote control RC, the motor  26  is energized and the reduction gearing  27  is properly rotated to impart rotation to the clutch body  28 . The energized solenoid in the solenoid housing  34  axially shifts the clutch body  29  into driven engagement with the rotating clutch body  28 . The drive gear  31  imparts drive motion to the toothed belt  37  and rotation to the shaft  45  via the toothed pulley  46 . The drive pulleys  47 ,  48  rotate and wind thereon the nylon ropes  72 ,  73  pulling the same downwardly relatively slowly but powerfully due to the reduction gearing  27 . The relatively high pulling forces are transferred via the pull bar  80  and the nylon ropes  81 , the universal joints  82  and the clamps  83  to the slide sheet SS which progressively forcefully but slowly pulls the slide sheet SS and the patient P thereupon from the position shown in  FIG. 3  to the position shown in  FIG. 4  and slightly beyond the latter until the patient is located centrally upon the gurney mattress Mg. A proximity switch Ps ( FIGS. 1 and 4 ) is associated with the upper end of each upper tube  56 ,  58  for engagement by the pull bar  80  to cut power to the motor  26  should the care-giver/attendant fail to appropriately de-energize the motor  26  and/or the solenoid  34  through the remote control RC. The clamps  83  are disconnected from the edge E of the slide sheet SS. The gurney G and the patient transfer mechanism  10  are disconnected from the bed B and the gurney G, respectively, by undoing the respective Velcro® straps VS and  87 . The patient P can then be transported, as need be, by the gurney G. 
         [0023]    In order to transfer the patient from the gurney G to the bed B, the patient transfer mechanism  10  is merely rolled from the position shown in  FIG. 2  to the left side thereof with the platform  11  beneath the bed B projecting toward the gurney G. The process just described with respect to  FIGS. 2 through 4  is then repeated to transfer the patient P from the gurney G to the bed B. 
         [0024]    Although a preferred embodiment of the invention has been specifically illustrated and described herein, it is to be understood that minor variations may be made in the apparatus without departing from the spirit and scope of the invention, as defined by the appended claims.