Abstract:
A patient lift assembly including a boom, a cradle, and a pin for securing the boom and the cradle. The pin has a head formed at a first end thereof and a locking mechanism near a second end thereof for capturing the cradle and the boom therebetween.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     This invention relates in general to beds and more particularly, to means for relocating an invalid. Most particularly, the invention relates to structure for attaching cradles to patient lifts.  
         [0002]     Patient lifts are generally known in the health care industry. Such known lifts typically include a support arm or boom and a sling hanger or cradle supported by the boom. A sling for lifting a patient is hung from the cradle. There are several types of cradles including, for example, 2-point cradles, 4-point cradles, and weight scale equipped cradles. Cradles are typically secured to the boom by nut and bolt fastener assemblies. Such assemblies require mechanical tools and mechanical skill to properly remove and replace the cradle.  
         [0003]     What is needed is an improved patient lift assembly that does not require mechanical tools or mechanical skill for properly removing and replacing the cradle.  
       BRIEF SUMMARY OF THE INVENTION  
       [0004]     This invention toward a patient lift that meets the foregoing needs. The patient lift has a boom, a cradle, and a pin for releasably attaching the boom and cradle. The pin has a head formed at a first end thereof and a locking mechanism near a second end thereof for capturing the cradle and the boom therebetween.  
         [0005]     Various objects and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]      FIG. 1  is a sectional view of a portion of a patient lift in accordance with the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0007]     Referring now to the drawings, there is illustrated in  FIG. 1 a  portion of a patient lift  10 . The lift  10  includes a boom  12 . The boom  12  has a first support member, which in the illustrated embodiment is a yoke end  14 . The yoke end  14  includes first and second prongs  16  and  18 . Although the prongs  16  and  18  shown protrude in a generally parallel arrangement, other arrangements may be suitable for carrying out the invention. A first generally circular bore  20  having a first generally longitudinal axis is formed through the first prong  16 . Similarly, a second generally circular bore  22  having a second generally longitudinal axis is formed through the second prong  18 . Preferably, the first and second axes are substantially coaligned. It should be appreciated that the bores  20  and  22  may have a shape other than the generally cylindrical shape described.  
         [0008]     The lift  10  also includes a cradle  24 . The cradle  24  includes a second support member  26  protruding therefrom. A third bore  28  having a third generally longitudinal axis is formed through the second support member  26 . When the patient lift  10  is in an assembled configuration, as shown, the third axis is generally aligned with the first and second axes of the first and second bores  20  and  22 . Preferably, the first, second, and third bores  20 ,  22 , and  28  have substantially the same diameter, such that when the bores  20 ,  22 , and  28  are aligned, the bores  20 ,  22 , and  28  create a generally uniform cylindrical passageway. Although the third bore  28  shown is generally circular, other shapes may be suitable for carrying out the invention. It should also be appreciated that the first, second, and third bores  20 ,  22 , and  28  need not have substantially the same diameter.  
         [0009]     A sleeve  30  having a generally longitudinal hollow cylindrical body  32  with a passage therethrough is adapted to be disposed in the cylindrical passageway created by the bores  20 ,  22 , and  28 . Preferably, the body  32  is preferably longer than the passageway created by the bores  20 ,  22 , and  28  so that the body  32  extends beyond the first prong  16  and the second prong  18 . The sleeve  30  has a fourth generally longitudinal axis that is preferably aligned with the first, second, and third axes of the first, second, and third bores  20 ,  22 , and  28 . The sleeve body  32  has a first end  34  that preferably extends through the first bore  20 , a mid portion  35  extending through the third bore  28 , and a second end  36  that preferably extends through the second bore  22 . Thus, the crosswise outer dimensions (i.e., the vertical dimensions when viewing  FIG. 1 ) of the first end  34 , the mid portion  35 , and the second end  36  are less than the corresponding dimensions of the bores  20 ,  22 , and  28 .  
         [0010]     Although not necessary, a flange  38  may extend from the second end  36 . Preferably, the flange  38  has a radial portion  40  that is generally parallel to the second prong  18 , although this is largely dependent on the shape of the yoke end  14 . The flange  38 , also preferably, has an annular portion  42  that is generally perpendicular to the second prong  18 , although other orientations in relation to the second prong  18  are possible. The annular portion  42  defines a recess for shielding a locking mechanism, as will become apparent in the description that follows.  
         [0011]     A pin  44  has a shaft  46 . The sleeve  30  has a crosswise inner dimension that permits the pin  44  to pass therethrough. Although other shapes are possible, the shaft  46  is a generally longitudinal cylindrical shaft and thus has a diameter that is less than an inner diameter of the sleeve body  32 . The pin  44  has a fifth generally longitudinal axis that is preferably aligned with the first, second, third, and fourth axes of the first, second, and third bores  20 ,  22 , and  28 , and the sleeve  30 . The pin  44  has a first end  48  extending from the first bore  20  and a second end  52  extending from the second bore  22 . The first end  48  has a head  50 , or like member, and a locking mechanism  54  is provided near a second end  52 . The illustrated locking mechanism  54  includes a spring  56  and a barb  58 , although some other locking mechanism may be suitable for carrying out the invention. In the illustrated embodiment, the spring  56  and the barb  58  cooperate in a manner similar to a traditional spring-ball arrangement. The barb  58  includes a vertical edge  60  that is substantially perpendicular or transverse to the fifth generally longitudinal axis of the pin  44  (i.e., generally parallel to the radial portion  40 ). However, the edge  60  may be at some angle other than an angle that is perpendicular to the fifth generally longitudinal axis of the pin  44 . The barb  58  also includes a sloped edge  62  that is skewed to the fifth generally longitudinal axis of the pin  44 . Preferably, the sloped edge  62  and the fifth generally longitudinal axis of the pin  44  are angled at approximately 30° to 45°, although other angles may be suitable for carrying out the invention. It should be appreciated that the sloped edge  62  may take on a shape other than that shown. In operation, the sloped edge  62  is shaped to act as a cam surface for engagement with the sleeve  30  to displace the barb  58  upon inserting the shaft  46  through the sleeve  30 . Preferably, the radial portion  40  is suitable to function as an axial bearing to prevent wear due to friction between the yoke end  14  and the barb  58 .  
         [0012]     Although not necessary, a washer  64  may be disposed between the pin head  50  and the first prong  16  to function as an axial bearing to prevent wear due to friction between the pin head  50  and the first prong  16 . Preferably the washer has a stepped interior  66  having first and second end portions  68  and  70  and having a mid portion  72 . The dimensions of the first and second end portions  68  and  70  are preferably greater than the dimensions of the sleeve body  32  and the dimensions of the pin head  50  and the mid portion  72  are preferably greater than the dimensions of the shaft  46  and less than the dimensions of the head  50  such that second end portion  70  may fit over the sleeve body  32  and the shaft  46  may pass through the mid portion  72 , without permitting passage of the head  50 . The washer  64  defines a recess for receiving the head  50  of the pin  44  and shielding the head  50  to reduce risk of exposure to pinch points between the head  50  and the first prong  16 .  
         [0013]     In operation, to assemble the lift  10 , the cradle  24  is positioned relative to the boom  12  so that the third bore  28  is substantially aligned with the first and second bores  20  and  22 . The first end  34  of the sleeve  30  is guided through the second bore  22 , the third bore  28  and the first bore  20 . The washer  64  is placed adjacent the first end  34  of the sleeve  30  so that the stepped interior  66  is aligned with the sleeve body  32 . The second end  52  of the pin shaft  46  is guided through the stepped interior  66  of the washer  64 , and the interior of the sleeve body  32 . As the pin shaft  46  is guided thought the washer  64 , the stepped interior  66  cooperates with the sloped edge  62  of the barb  58  so that the barb  58  is depressed and does not interfere with the travel of the pin shaft  46 . Once the second end  52  of the pin shaft  46  is guided into the flange  38 , the spring  56  extends the barb  58 . The barb  58  cooperates with the flange  38  and the pin head  50  cooperates with the stepped interior  66  of the washer  64  to lock the lift  10  in the assembled position.  
         [0014]     To disassemble the lift  10 , the barb  58  is depressed by pressing against the sloped edge  62 , for example, with a finger tip, or any suitable object. The pin shaft  46  is then withdrawn. The sleeve  30  is then withdrawn, and the cradle  24  may be replaced with another cradle, not shown. Preferably, the annular portion  42  is suitable to function as a guard to shield the locking mechanism  54  from inadvertently being unlocked.  
         [0015]     The preferred embodiment of the present invention thus allows a variety of cradles to be changed quickly and easily. For example, the preferred embodiment of the present invention thus allows for rapid and easy interchange of various types of cradles, such as 2-point, 4-point and weight scale equipped cradles when patient caregivers select the a type of cradle for patient lifting other than the one already assembled. Removal and/or installation of a cradle can thus be achieved manually or with the use of a simple release object. Further, the preferred embodiment of the present invention thus guards against inadvertent disengagement, as there must generally be deliberate engagement of the locking mechanism to release the assembly of the lift.  
         [0016]     It should be appreciated that the first and second support members described above are provided for illustrative purposes and that other support members may be suitable for carrying out the invention. For example, the second member may be in the form of a yoke end that is adapted to receive that first support member. Moreover, the support members are not intended to be limited to the geometric shapes shown and described, and that other shapes may be suitable for carrying out the invention. It should further be understood that the invention is not intended to be limited to the sleeve and the pin shown and described above, and that other coupling assemblies may be similarly fashioned to readily permit the cradle to be releasably attached to the boom.  
         [0017]     It should be noted that the quick release pin  44  may allow for quick release of the cradle  24  from the boom  12  of a patient lift  10 . The sleeve  30  may provide protection for the pin  44 . That is to say, since the connection is an articulating connection, the sleeve  30  may function as a radial bushing or bearing. The flange  38  and washer  64  may function as axial bearings or bearing surfaces. The stepped interior  66  at one end may provide a recess into which the pin head  50  may be located. This may reduce that risk of presenting exposed pinch points. A similar recess at the other end may receive the locking mechanism  54  and thus shields the locking mechanism  54  from inadvertently being unlocked.  
         [0018]     The principle and mode of operation of this invention have been explained and illustrated in its preferred embodiment. However, it must be understood that this invention may be practiced otherwise than as specifically explained and illustrated without departing from its spirit or scope.