Patent Publication Number: US-11641950-B2

Title: Height adjustable bassinet

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to bassinets, and more specifically to medical grade bassinets of the type commonly used in a hospital and other medical environments. 
     Bassinets are often used in the medical industry to hold newborn babies and young infants, for example, up to about 4 months. In maternity wards and other medical environments, bassinets are often specially designed for use bedside as a place for a newborn or young infant to sleep or rest next to the mother&#39;s bed. For example, conventional bassinets used in a medical setting are often designed with rollers or wheels that allow the bassinet to be rolled up to the side of the mother&#39;s bed so that the mother can while remaining in bed interact with the newborn or young infant. Similarly, the bassinet can be rolled away from the bed when the mother is sleeping or when the newborn is resting in the nursery. 
     Bassinets are available in a variety of conventional designs, with each of the conventional designs suffering from shortcomings. For example, some conventional bassinets are supported upon a pedestal, chest of drawers or other fixed-height structure. Conventional fixed-height structures help to provide a stable support for the bassinet, but they can be heavy and bulky, and limit the mobility of the bassinet. Fixed-height structures can also make it more difficult for a mother to interact with a newborn in the bassinet. This can be particularly true when the mother is reclining in a height-adjustable bed. Fixed-height structures can also have a negative impact on caregiver ergonomics. 
     To facilitate bedside use, some conventional medical grade bassinets are height adjustable. For example, some bassinets are supported upon height adjustable columns that can be extended and retracted to raise and lower the height of the bassinet tub. While height adjustable bassinets are available, conventional height adjustment actuators can be difficult or inconvenient to operate. 
     Some conventional bassinets, including some conventional height adjustable bassinets, have drawers that can be used to store supplies and other items. In some conventional systems, the drawers can be opened from either side of the bassinet so that the user is not required to move to a specific side of the bassinet to gain access to the drawers. For example, some bassinets of this type include drawers fixed to conventional two-way drawer slides. While they provide easy movement of the drawers, conventional drawer slides are securely affixed to the drawers making it more difficult to clean the drawers. Perhaps an even bigger concern is that two-way drawers have a tendency to slide open when the bassinet is moved. For example, when rolling a mobile bassinet around a corner, the drawer will often slide open with centrifugal force caused by the inertia of the drawer and its contents. The problem is worsened when the drawer is holding a heavy load. 
     There is an ongoing need for an improved medical grade bassinet that provides enhanced performance and functionality in a maternity ward or other hospital or medical settings. 
     SUMMARY OF THE INVENTION 
     The present invention provides a bassinet that is height-adjustable and specially configured for bedside use in a medical environment. The bassinet generally includes a base, a pair of height adjustable columns, a bassinet support surface, a bassinet tub and a height adjustment assembly. In one embodiment, each column includes an assist cylinder having an actuator that is accessible through the top of the column. The height adjustment assembly includes an actuator assembly configured to operate both assist cylinders simultaneously through manual operation of actuators, such as paddles, located approximately in four corners of bassinet support surface. 
     In one embodiment, the height adjustment system includes a pair of paddle assemblies mounted under the bassinet support surface with one extending along each side. Each paddle assembly is operatively coupled to the assist cylinder actuator by a linkage so that manual operation of a paddle functions to actuate the assist cylinders to facilitate adjustment of the height of the bassinet support surface. 
     In one embodiment, each paddle assembly includes a spanning rod with paddles mounted at or near opposite ends. The spanning rod is rotatably mounted to the undersurface of the table top. The paddles may extend in a direction generally perpendicular to the longitudinal axis of the spanning rod so that up and down pivotal movement of a paddle causes rotation of the spanning rod. 
     In one embodiment, the spanning rods are operatively coupled to the assist cylinder actuator by a dual linkage, which is configured so that operation of any single paddle simultaneously operates both assist cylinder actuators, thereby allowing the bassinet support surface to be raised and lowered. 
     In one embodiment, the dual linkage includes a pair of drive rods, an array of pivot arms and a pair of actuator rods. In one embodiment, each drive rod is uniquely associated with one of the paddle assemblies. In one embodiment, each paddle assembly has a central leg that extends from the spanning rod and moves the associated drive rod when either paddle assembly is rotated into the release position. In one embodiment, the spanning rods extend generally longitudinally and the drive rods extend generally transversely with respect to the bassinet support surface. The central leg of each paddle assembly may engage the associated drive rod such that rotation of the spanning rod causes arcuate travel of the central leg, which in turn causes transverse linear movement of the drive rod. 
     In one embodiment, the array of pivot arms includes four pivot arms arranged between the two drive rods and the two actuator rods. Each of the actuator rods is uniquely associated with the actuator of an associated one of the assist cylinders such that reciprocating linear movement of an actuator rod results in selectively engaging or disengaging the actuators of both assist cylinders. The pivot arms are configured to translate movement of either drive rod into simultaneous movement of both actuator rods. For example, in the illustrated embodiment, a pair of pivot arms are uniquely associated with each of the drive rods, and a pair of pivot arms are uniquely associated with each of the actuator rods. The drive rods, pivot arms and actuator rods are arranged so that linear movement of either drive rod in a transverse direction causes pivoting movement of two associated pivot arms, which in turn causes linear movement of both actuator rods and both assist cylinder actuators. 
     In one embodiment, the pivot arms are disposed in a generally rectangular configuration. For example, each pivot arm may be generally L-shaped with a first leg engaging a drive rod and a second leg engaging an actuator rod. 
     In one embodiment, each drive rod includes a head configured to remain engaged with the two associated pivot arms through the full range of transverse motion of the drive rod. 
     In one embodiment, each actuator rod includes a head configured to remain engaged with the two associated pivot arms through the full range of longitudinal motion of the actuator rod. 
     In one embodiment, the height adjustment system is mounted to a support frame affixed to the top of the adjustable height columns and the bottom of the bassinet support surface. The support frame may be shaped to define a space housing the dual linkage in a concealed location between the support frame and the bassinet support surface. 
     In the illustrated embodiment, the actuator of the assist cylinder is resiliently biased in the locked position. In this embodiment, the actuator assembly components are arranged so that movement of the assist cylinder actuator into the locked position urges the various component of the actuator assembly into their respective locked position. As a result, the height of the bassinet support surface remains locked and the actuator assembly remains in the locked position except when a user is manually operating a paddle. 
     In one embodiment, the present invention includes a drawer disposed below the bassinet support surface. The drawer includes a drawer frame that is secured by two-way drawer slides that allow the drawer to be pulled out from either side of the bassinet. The drawer includes a removable tub that is fitted into the drawer frame. The drawer frame may include a pair of drawer fronts and a pair of drawer sides. The drawer tub may rest upon the drawer sides and be easily removed for cleaning by pulling out the drawer and lifting the drawer tub out of the drawer frame. 
     In one embodiment, the drawer includes a centering arrangement that helps to maintain the drawer in the centered/closed position. In one embodiment, the drawer frame is supported within a hanging pedestal by a pair of sidewalls. A finger extends outwardly from the approximate center of each drawer side toward the sidewalls. Each sidewall includes a pair of spring-loaded ball bearings (e.g. ball plungers) that are positioned along the path of the finger toward the center of the sidewall. The ball bearing are arranged so that the finger is situated between the two spring-loaded ball bearings when the drawer is in the centered/closed position, and so that the finger must be depress one of the ball bearings to move the drawer out of the centered/closed position. The amount of force required to move the drawer out of the centered/closed position can be controlled, for example, by varying the spring force of the ball plunger or by varying the shape of the portion of the finger that interfaces with the ball bearings. 
     In one embodiment, the present invention includes a pullout worksurface disposed below the bassinet support surface and above the dual linkage. The pullout worksurface is supported on raised portions of the support frame and can be pulled out from opposite ends of the bassinet. 
     In one embodiment, the worksurface includes a stop arrangement that limits movement of the worksurface to prevent it from being pulled out too far. In one embodiment, the worksurface includes a finger that extends up into a guide slot defined in the bottom of the bassinet support surface. The finger travels along the guide slot as the worksurface is moved. The range of motion of the pullout worksurface is defined by the length of the guide slot. 
     In one embodiment, the pullout worksurface has a centering assembly that helps to hold the worksurface in the closed position, which may be a centered position. The centering assembly may include a pair of spaced-apart spring-loaded bearings that extend into the guide slot and the path of the finger. The two spring-loaded bearings are spaced apart a distance slightly greater than the width of the finger. When the pullout worksurface is centered, the finger is positioned between the two bearings. To pull out the worksurface, the user must pull the worksurface with enough force to overcome the bias of the spring-loaded bearing. 
     The present invention provides a simple and effective height adjustment system for a bassinet having two height adjustable columns located remotely from one another. The height adjustment allows a user to actuate the height adjustment system from any of the four corners of the bassinet support surface. The use of a generally symmetric height adjustment system helps to balance the manual force required to operate the system for each of the corners. The use of paddle assemblies with a spanning rod and a central leg facilitates operation by centralizing the drive rods and allowing for actuator rods of generally equal length. Similarly, the use of a rectangular array of generally identical pivot arms provides a symmetric arrangement with uniform operation from all four paddles. The arrangement of four pivot arms allows inward motion of either drive rod to cause opposed linear movement of the two actuator rods, which in turn moves the two assist cylinder actuators from the locked to the unlocked position. Further, the internal bias of the assist cylinder actuators biases the actuator rods, the pivot arms, the drive rods, the spanning rods and the paddles into the locked position without the need for supplemental biasing components, such as springs. The use of a drop-in drawer tub makes it easy for a user to remove the drawer tub for cleaning, which is of increasing importance to user concerned with preventing the spread of infection. The pullout worksurface gives the user an additional surface that can be used when desired. Given that the bassinet support surface is generally supporting a bassinet tub, the pullout worksurface can be extremely convenient. The stop arrangement helps to retain the worksurface in the closed, center position until intentionally drawn out by the user. Further, it provides tactile feedback to the user as the moves the worksurface into the closed position. 
     These and other objects, advantages, and features of the invention will be more fully understood and appreciated by reference to the description of the current embodiment and the drawings. 
     Before the embodiments of the invention are explained in detail, it is to be understood that the invention is not limited to the details of operation or to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention may be implemented in various other embodiments and of being practiced or being carried out in alternative ways not expressly disclosed herein. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including” and “comprising” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items and equivalents thereof. Further, enumeration may be used in the description of various embodiments. Unless otherwise expressly stated, the use of enumeration should not be construed as limiting the invention to any specific order or number of components. Nor should the use of enumeration be construed as excluding from the scope of the invention any additional steps or components that might be combined with or into the enumerated steps or components. Any reference to claim elements as “at least one of X, Y and Z” is meant to include any one of X, Y or Z individually, and any combination of X, Y and Z, for example, X, Y, Z; X, Y; X, Z; and Y, Z. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1 A  is a top perspective view of a bassinet in accordance with an embodiment of the present invention. 
         FIG.  1 B  is a top perspective view of a bassinet in accordance with an embodiment of the present invention with the bassinet tub removed and portions in broken lines to emphasize the height adjustment system. 
         FIG.  2 A  is a sectional bottom perspective view of a portion of the bassinet. 
         FIG.  2 B  is an enlarged view of a portion of  FIG.  2 A . 
         FIG.  3    is a top view of the height adjustment system in the locked position with the outline of the bassinet support surface shown in broken lines. 
         FIG.  4    is a top view of the height adjustment system in the unlocked position with one of the drive rod moved inwardly with the outline of the bassinet support surface shown in broken lines. 
         FIG.  5    is a perspective view of the bassinet with various components shown in broken lines to show the height adjustment system in the locked position with the bassinet tub removed and portions in broken lines to emphasize the height adjustment system. 
         FIG.  6    is a perspective view of the bassinet with various components shown in broken lines to show the height adjustment system in the unlocked position with the bassinet tub removed and portions in broken lines to emphasize the height adjustment system. 
         FIG.  7    is an end view of the bassinet showing a drawer tub being removed from the drawer with the bassinet tub removed and portions in broken lines to emphasize the drawer. 
         FIG.  8    is a perspective view of the bassinet showing a drawer tub being removed from the drawer with the bassinet tub removed and portions in broken lines to emphasize the drawer. 
         FIG.  9 A  is a perspective view of the bassinet with portions in broken lines to show the pullout worksurface. 
         FIG.  9 B  is an enlarged view of Area  9 B of  FIG.  9 A . 
         FIG.  10 A  is a perspective view of the bassinet with portions in broken lines to show the pullout worksurface extended from one end of bassinet. 
         FIG.  10 B  is an enlarged view of Area  10 B of  FIG.  10 A . 
         FIG.  11 A  is a perspective view of the bassinet with portions in broken lines and portions removed to show the centering arrangement on one side of the drawer. 
         FIG.  11 B  is an enlarged view of Area  11 B of  FIG.  11 A . 
         FIG.  11 C  is a sectional view showing the drawer centering arrangement on one side of the drawer. 
     
    
    
     DESCRIPTION OF THE CURRENT EMBODIMENT 
     A medical grade bassinet  10  having a height adjustment system  12  in accordance with an embodiment of the present invention is shown in  FIGS.  1 A and  1 B . In this embodiment, the bassinet  10  includes a bassinet support surface  14  that is mounted upon a pair of height adjustable columns  16   a - b . A bassinet tub  100  may be placed atop the bassinet support surface  14  within a pair of retention rails  102 . An assist cylinder  18   a - b  is situated within each column  16   a - b . The assist cylinders  18   a - b  each include an actuator  20   a - b  that is accessible from above the column  16   a - b  (See  FIGS.  2 A and  2 B ). The height adjustment system  12  includes an actuator assembly having a pair of paddle assemblies  22  that are rotatably mounted to the bassinet support surface  14  (See  FIG.  3   ). The paddle assemblies  22  are operatively coupled to the actuator  20  by a linkage so that movement of any paddle moves the actuators  20  for both assist cylinders  18   a - b  to the unlocked position, thereby allowing adjustment to the height of the bassinet support surface  14  (See  FIG.  4   ). In this embodiment, the paddle assemblies  22  are coupled to the actuator by a dual linkage  24  having a pair of drive rods  26 , an arrangement of pivot arms  30  and a pair of actuator rods  28 . In the illustrated embodiment, the height adjustment system  12  is essentially symmetrical in both the longitudinal and transverse directions. 
     Although described in the context of a bassinet, the height adjustment system of the present invention may be incorporated into other types of tables or work surfaces that incorporate a pair of remotely disposed assist cylinders. Directional terms, such as “vertical,” “horizontal,” “top,” “bottom,” “upper,” “lower,” “inner,” “inwardly,” “outer” and “outwardly,” are used to assist in describing the invention based on the orientation of the embodiments shown in the illustrations. The use of directional terms should not be interpreted to limit the invention to any specific orientation(s). 
     The present invention will now be described in more detail with respect to the embodiment shown in  FIGS.  1 - 10   . In this embodiment, the bassinet  10  generally includes a base  11 , a pair of height adjustable columns  16   a - b  affixed to and extending upwardly from the base  11 , a pair of assist cylinders  18   a - b  (one mounted in each height adjustable column  16   a - b ), a bassinet support surface  14  mounted atop the height adjustable columns  16   a - b  and a bassinet tub  13  disposed atop the support surface  14 . A bassinet tub  100  is disposed atop of the bassinet support surface  14  within retention rails  102 . In the illustrated embodiment, the bassinet  10  also includes a hanging pedestal  110  suspended from the bassinet support surface  14 . The hanging pedestal  110  includes a drawer  112  that can be opened from either side of the bassinet  10 . In the illustrated embodiment, the bassinet  10  also includes a pullout worksurface  150  that is mounted in a cavity  152  defined below the bassinet support surface  14  and can be pulled out from either end of the bassinet  10 . 
     In the illustrated embodiment, the base  11  provides a mobile pedestal to support the bassinet  10 . As perhaps best shown in  FIG.  1 A , the base  11  includes a plurality of casters  13  that allow the bassinet  10  to be easily rolled about from one location to another. In alternative applications, the casters may be replaced by wheels, slides or other mechanisms that facilitate movement of the bassinet  10 . In other alternative embodiments, the columns  16   a - b  may be attached to a base  11  without wheels or casters, or directly to floor or other underlying structure. 
     Referring again to  FIG.  1 A , the height adjustable columns  16   a - b  are affixed to the base  11 , for example, by fasteners, welding or other types of attachment. As shown, the columns  16   a - b  are disposed toward opposite longitudinal ends of the base  11  to provide support near opposite longitudinal ends of the bassinet support surface  14 . In the illustrated embodiment, the bassinet support surface  14  is generally rectangular. However, the size, shape and configuration of the bassinet support surface  14  may vary from application to application. For example, the bassinet support surface  14  may alternatively be square, oval, kidney shaped or essentially any other desired shape. 
     In the illustrated embodiment, the two columns  16  are essentially identical and each one is a telescopic column with an upper section  32  and a lower section  34  that are interfitted to different degrees to vary the height of the column and the bassinet support surface  14 . In the illustrated embodiment, a bottom portion of the upper section  32  is telescopically fitted over an upper portion of the lower section  34 . Bearing, bushings, rollers or other friction reducing components may be fitted between the upper section  32  and the lower section  34  to facilitate smooth and stable telescopic movement. In the illustrated embodiment, the lower section  34  of each column  16   a - b  is affixed to the base  11  and the upper section of each column is affixed to the undersurface of the bassinet support surface  14 . The size, shape and configuration of the height adjustable columns  16  may vary from application to application. 
     To control and assist with telescopic movement of the columns  16   a - b , an assist cylinder  18   a - b  is fitted into the interior of each column  16   a - b  between the upper section  32  and the lower section  34 . In  FIG.  2 A , a portion of the upper section  32  of each column  16   a - d  is removed to show the upper end of each assist cylinder  18   a - b  emerging from inside the columns  16   a - b . For example, one end of each assist cylinder  18   a - b  is directly or indirectly affixed to the associated upper section  32  and the other end of each assist cylinder  18   a - b  is directly or indirectly affixed to associated lower section  34 . Each assist cylinder  18   a - b  has locked and unlocked states. In the locked state, the assist cylinders  18   a - b  prevent relative motion between the associated upper section  32  and lower section  34 , thereby retaining the bassinet support surface  14  at the current height. In the unlocked state, the assist cylinders  18   a - b  allow relative motion between the associated upper section  32  and lower section  34 . 
     The assist cylinders  18   a - b  of the illustrated embodiment include internal bias that helps to offset the weight of the height adjustable components of the bassinet  10  making it easier for the user to raise and lower the bassinet support surface  14 . The assist cylinders  18   a - b  may be one of a variety of conventional assist cylinders available from a variety of well-known suppliers. For example, the assist cylinders  18   a - b  may be a Bloc-O-Lift locking gas spring (available from Stabilus GmbH) with a diameter of 28 mm, an extended length of 41 inches and a compressed length of 23 inches. The force of the gas spring may vary from application to application, for example, depending in part on the weight of the components of the bassinet  10  carried by the columns  16   a - b . The described assist cylinders  18   a - b  and their specifications are merely exemplary. 
     In the illustrated embodiment, each assist cylinder  18   a - b  includes an actuator  20  that is mechanically manipulated to move the assist cylinder  18  between the locked and unlocked states (See  FIGS.  2 A and  2 B ). In the illustrated embodiment, the actuator  20  is biased in the locked position and user manipulation is required to move it into the unlocked position. For example, as perhaps best shown in  FIG.  2 B , the actuator  20  of the illustrated embodiment is a plunger that protrudes from the upper end of the assist cylinder  18 . When the plunger  20  is extended, the assist cylinder  18   a - b  is in the locked state. When the plunger  20  is depressed, the assist cylinder  18   a - b  is in the unlocked state. 
     As noted above, the height adjustment system  12  of the illustrated embodiment also includes an actuator assembly that mounts to the undersurface of the bassinet support surface  14  and is operatively coupled to the assist cylinders  18   a - b  of both columns  16   a - b . In use, the actuator assembly  36  provides a mechanism to allow manipulation of the assist cylinders  18   a - b  from a plurality of convenient locations about the bassinet support surface  14 . The actuator assembly of this embodiment includes a pair of paddle assemblies  22  and a dual linkage  24  that operatively couples the paddle assemblies  22  to the assist cylinders  18   a - b . The two paddle assemblies  22  are mounted along opposite longitudinal sides of the bassinet support surface  14 . In the illustrated embodiment, each paddle assembly  22  includes a spanning rod  38  with paddles  40  mounted at or near opposite ends. The spanning rod  38  is rotatably mounted to the undersurface of the bassinet support surface  14 . As shown in  FIG.  2 A , each spanning rod  38  may be affixed to the bassinet support surface  14  by a plurality of brackets  44 . The brackets  44  may be sized to closely receive the spanning rods  38  with sufficient clearance to allow rotational movement of the spanning rods  38  within the brackets  44 . Bearings, bushing or other friction reduction materials may be fitted between the brackets  44  and the spanning rods  38 . As discussed below, the spanning rods  38  may also be attached to support frame  54 . 
     The paddles  40  may extend in a direction generally perpendicular to the longitudinal axis of the spanning rod  38  so that up and down pivotal movement of a paddle  40  causes rotation of the associated spanning rod  38  about its longitudinal axis. In the illustrated embodiment, each paddle  40  is designed to be operated by a single hand. For example, the paddles  40  include a handle portion  48  configured for easy manipulation and a mounting portion  50  configured for attachment to a spanning rod  38  (See  FIG.  2 A ). To facilitate mounting of the paddles  40 , the spanning rods  38  of the illustrated embodiment may include opposed end segments  46  that extend at approximately 90 degrees to the longitudinal axis of the spanning rods  38 . In this embodiment, the mounting portion  50  of each paddle  40  defines a mounting hole that is fitted over the free end of the corresponding lateral segment  46 . A set screw (not shown) may be used to secure each paddle  40 , if desired. The illustrated paddles  40  are merely exemplary. The size, shape and configuration of the paddles may vary from application to application. Although referred to as “paddle” assemblies, the paddle assemblies  22  need not include “paddles”, but may instead include other structures suitable for manually rotating the assemblies  22 . By way of example, the paddles may be replaced by essentially any alternative structure suitable for providing handles to operate the height adjustment system  12 . The paddles need not be separate from the spanning rods. For example, the ends of the spanning rods  38  may be bent or otherwise configured to form paddles that can be manipulated directly without any separate components. 
     In the illustrated embodiment, each spanning rod  38  includes a radial leg  52  configured to interact with a linkage that operatively joins each paddle assembly  22  to both assist cylinders  18   a - b . In the illustrated embodiment, the radial legs  52  extend radially from the corresponding spanning rod  38  in a generally upward direction from the approximate center of the spanning rod  38 . The radial legs  52  extend upwardly through corresponding openings  86  in the support frame  54  (discussed below). As the paddle assembly  22  is rotated the radial leg  52  travels in a sweeping motion (compare  FIGS.  6 ,  7  and  8   ). In the illustrated embodiment, the sweeping motion of the radial leg  52  is used to impart linear motion to a mating component in the dual linkage  24 . More specifically, as described in more detail below, each radial leg  52  is configured to directly engage and provide linear motion to the associated drive rod  26 . 
     The paddle assemblies  22  are operatively coupled to the actuator  20  so that appropriate rotational movement of either paddle assembly  22  moves the assist cylinder actuators  20  to the unlocked position, thereby allowing adjustment to the height of the bassinet support surface  14  and the various components carried by the bassinet support surface  14 . 
     In the illustrated embodiment, the paddle assemblies  22  are coupled to the actuator  20  by a dual linkage  24  having a pair of drive rods  26 , a pair of actuator rods  28 , a plurality of pivot arms  30  and a pair of links  82 . As shown in  FIGS.  3  and  4   , the drive rods  26  are mounted to the undersurface of the bassinet support surface  14  and are capable of reciprocating linear movement. For example, in the illustrated embodiment, each drive rod  26  is affixed to the support frame  54  by a pair of brackets  64 . The illustrated brackets  64  are attached to the undersurface of bassinet support surface  14  by fasteners and are configured to allow linear movement of the drive rods  26 . Each bracket  64  may include bushings, bearings or other components to reduce friction and allow easy movement of the drive rod  26  with respect to the bracket  64 . Each drive rod  26  is disposed between a paddle assembly  24  and the plurality of pivot arms  30 , and more specifically between the radial leg  52  of the associated spanning rod  38  and two associated pivot arms  30 . Each drive rod  26  includes a head  27  configured to engage a pair of associated pivot arms  30 . Because the associated pivot arms  30  swing away from each other during operation, the head  27  is of sufficient size to remain in contact with both pivot arms  30  throughout the full range of motion. 
     Similar to the drive rods  26 , the actuator rods  28  are mounted to the undersurface of the bassinet support surface  14  and are capable of reciprocating linear movement. In the illustrated embodiment, each actuator rod  28  is affixed to the support frame  54  by a pair of brackets  68  (See  FIGS.  3  and  4   ). The illustrated brackets  68  are attached to the undersurface of bassinet support surface  14  by fasteners and are configured to allow linear movement of the actuator rods  28 . Each bracket  68  may include bushings, bearings or other components to reduce friction and allow easy movement of the actuator rods  28 . Each actuator rod  28  is disposed between the plurality of pivot arms  30  and a link  82 . More specifically, each actuator rod  28  is disposed between a corresponding pair of pivot arms  30  and a corresponding link  82 . Each actuator rod  28  includes a head  29  configured to engage the associated pair of pivot arms  30 . Because the associated pivot arms  30  swing away from each other during operation, the head  29  is of sufficient size to remain in contact with the associated pivot arms  30  throughout the full range of motion. 
     The dual linkage  24  includes a pair of links  82  that translate outwardly linear movement of the actuator rods  28  into downward movement of the assist cylinder actuators  20 . In this embodiment, a separate link  82  is positioned between each actuator rod  28  and the corresponding assist cylinder actuator  20 . As shown, each link  82  of the illustrated embodiment is a generally “L” shaped component that is pivotally mounted adjacent to an associated actuator  20 . For example, as shown in  FIG.  2 B , each link  82  may be affixed by a pin  84  that supports the link  82  and permits it to pivot with respect to the column  16   a - b . Although the illustrated links  82  are generally “L” shaped, the linkage  24  may include one or more alternative components capable of operating the actuators  20  in response to linear movement of the actuator rods  28 . In use, each link  82  translates generally outward linear movement of the corresponding actuator rod  28  into generally downward motion appropriate to depress the corresponding actuator  20  and release the corresponding assist cylinder  18   a - b.    
     In this embodiment, the array of pivot arms  30  are configured to translate inward linear motion of the drive rods  26  into outward linear motion of the actuator rods  28 . As shown, the drive rods  26  are arranged approximately normal to the actuator rods  28 . In this embodiment, the bassinet support surface  14  is generally rectangular and the paddle assemblies  22  extend along opposite longitudinal edges of the bassinet support surface  14 . As a result, the drive rods  26  move linearly in a transverse direction and the actuator rods  28  move linearly in a longitudinal direction. Referring again to  FIGS.  3  and  4   , the dual linkage  24  of the illustrated embodiment includes four pivot arms  30  arranged in a generally rectangular array. Each illustrated pivot arm  30  is generally L-shaped, including a first leg  72  and a second leg  74  arranged at about 90 degrees from one another. Each pivot arm  30  is pivotally secured to the undersurface of the bassinet support surface  14  at the vertex of the first leg  72  and the second leg  74 . For example, a through-hole may be defined at the vertex and the pivot arm may be secured to the undersurface of the bassinet support surface  14  (e.g. support frame  54 ) by a fastener extending through the through-hole. Bushings, bearings or other components intended to reduce friction may be disposed within the through-hole about the fastener to facilitate smooth, easy and uniform pivotal motion of the pivot arm  30 . The first leg  72  of each pivot arm  30  is operatively engaged with the corresponding drive rod  26  and more specifically with the head  27  of the corresponding drive rod  26 . The second leg  74  of each pivot arm  30  is operatively engaged with a corresponding actuator rod  28  and more specifically the head  29  of the corresponding actuator rod  28 . 
     Operation of the height adjustment assembly  12  will now be described with reference to  FIGS.  3  and  4    and to  FIGS.  5  and  6   . In use, upward movement of any one of the four paddles results in rotational movement of the corresponding spanning rod  38 , which in turn moves the radial leg  52  of that spanning rod  38  inwardly. Inward movement of the radial leg  52  moves the associated drive rod  26  linearly inward into the two associated pivot arms  30 , and more specifically the head  27  of the moving drive rod  26  operatively engages and moves inwardly the first leg  72  of each associated pivot arm  30 . Inward movement of the first legs  72  causes each of the two associated pivot arms  30  to pivot about its mounting point pivoting the second leg  74  outwardly into operative engagement with the associated actuator rod  28 . As shown, the second leg  74  of each moving pivot arm  30  operatively engages the head  29  of the corresponding actuator rod  28  with the two pivot arms  30  pushing the actuator rods  28  outwardly in opposite directions. This outward movement causes each actuator rod  28  to engage and move the corresponding link  82 . The links  82  pivot to translate the outward linear movement of the actuator rods  28  into downward depression of the actuators  20 , thereby simultaneously releasing the assist cylinder  18   a - b  of both columns  16   a - b  and allowing the bassinet support surface  14  to be raised or lowered as desired. Transition between the locked and unlocked conditions may be best seen by comparing  FIG.  3    (locked) to  FIG.  4    (unlocked) and comparing  FIG.  5    (locked) to  FIG.  6    (unlocked). 
     If desired, the lengths of the drive rods  26  and/or the actuator rods  28  may be adjustable to allow tuning of the dual linkage  24 . For example, an adjustment screw (not shown) may be threaded into the outer end of each drive rod  26  and/or each actuator rod  28 . The adjustment screw may be threaded into or out of the rod to vary the effective overall length of that rod. Alternatively or in addition, one or more adjustment screws may be installed in the legs  72 ,  74  of the pivot arms  30  and/or the radial legs  52  of the spanning rods  38  to allow adjustment. 
     In the illustrated embodiment, the height adjustment assembly  12  is configured to be generally symmetrical about the transverse and longitudinal axes of the bassinet support surface. For example, the paddles assemblies  22  are generally identical and each has a centrally positioned radial leg  52 . The two drive rods  26  are generally identical and extend along a generally central transverse axis. The two actuator rods  28  are generally identical and extend along a generally central longitudinal axis. The pivot arms  30  are centrally located and arranged so that inward movement of either drive rod  26  results in equal and opposite outward movement of both actuators rods  28 . As a result of these symmetries, the dual linkage  24  (and more generally the height adjustment assembly  12 ) is balanced and provides stable and uniform operation from all four paddles. 
     In the illustrated embodiment, the assist cylinder actuator  20  is biased in the locked position (See  FIGS.  2 A and  2 B ). The actuator assembly  36  is configured to use the bias in the assist cylinder actuator  20  to bias the various components of the height adjustment assembly  12  in their locked positions. More specifically, when the user ceases applying enough force to a paddle assembly  22  to unlock the assist cylinders  18   a - b , the bias of the assist cylinder actuators  20  urge the bottom legs of the links  82  upwardly causing the opposite legs of the links  82  to pivot inwardly forcing the associated actuator rods  28  to move inwardly. The inwardly moving actuator rods  28 , in turn, engage and move the second legs  74  of the pivot arms  30 , thereby pivoting second legs  74  inwardly and the first legs  72  outwardly. The outward movement of the first legs  72  of the pivot arms  30  pushes both of the drive rods  26  outwardly in opposite directions. Each drive rod  26  engages and swings the associated radial leg  52  outwardly, such that the associated paddle assembly  22  and attached paddles, move into the locked position. 
     In the illustrated embodiment, the bassinet support surface  14  includes a support frame  54  that carries the height adjustment system  12 . The illustrated support frame  54  is affixed to the top of the column  16  and the bottom of the bassinet support surface  14 . For example, in this embodiment, the support frame  54  is secured to both columns  16   a - b  and the bassinet support surface  14  by fasteners. In the illustrated embodiment, the undersurface of the bassinet support surface  14  is shaped to receive the dual linkage  24 . For example, the bassinet support surface  14  may include one or more voids into which the dual linkage  24  is fitted. In the illustrated embodiment, the paddles assemblies  22  are secured to the undersurface of the support frame  54 . For example, as perhaps best shown in  FIG.  2 A , each paddle assembly  22  may be rotatably affixed to the support frame  54  by brackets  60 . The brackets  60  may be secured to the support frame by screws or other fasteners. Although mounted to the top surface of the support frame  54 , the dual linkage  24  may alternatively be mounted to the bottom surface of the support frame  54 . As noted above, the radial legs  52  may extend from below the support frame  54  to the dual linkage  24  mounted atop the support frame  54 . For example, the radial legs  52  may extend through openings  86  of sufficient size to accommodate the radial legs  52  through their full range of motion. The support frame  54  is merely exemplary and the dual linkage  24  may be mounted to the table  10  using essentially any suitable alternative construction. For example, the dual linkage  24  may be secured directly to the bassinet support surface  14 . In that alternative, the brackets securing the various components to the support frame  54  can be used to secure those components directly to the undersurface of the bassinet support surface  14 . 
     As noted above, the bassinet  10  of the illustrated embodiment also includes a hanging pedestal  110  including a drawer  112  that can be opened from either side of the bassinet  10  (See  FIGS.  7  and  8   ). In this embodiment, the hanging pedestal  110  includes a pair of sidewalls  114 . The sidewalls  114  may be mounted to the bassinet support surface  14 , the support member  54  and/or the upper sections of the adjustable height support columns  16   a - b . A pair of supports  132  may extend between the sidewalls  114  as shown in  FIG.  8    to provide supplemental support to the sidewalls  114 . The supports  132  may be rods affixed at opposite ends to the sidewalls  114 . The drawer  112  generally includes a drawer frame  116  and a drawer tub  118 . The drawer frame  116  of the illustrated embodiment includes a pair of drawer fronts  120  and a pair of drawer sides  122  arranged in a rectangular configuration. The drawer frame  116  defines a rectangular opening configured to receive and seat the drawer tub  118 . In the illustrated embodiment, the drawer tub  118  includes contoured sidewall that forms a central shoulder  124 . The central shoulder  124  is configured to rest up the tops of the two drawer sides  122  when the drawer tub  118  is properly seated in the drawer frame  116 . In this embodiment, the drawer frame  116  is movably mounted to the pedestal sidewalls  114  by a pair of drawer slides  126 . The drawer slides  126  support opposite sides of the drawer frame  116 . In this embodiment, the drawer slides  126  are two-way drawer slides that allow the drawer  112  to be pulled out from either side of the bassinet  14 . In the illustrated embodiment, the drawer tub  118  is a molded one-piece component that can be easily cleaned and disinfected. The drawer tub  118  may be molded from Kydex or other suitable materials. Although  FIGS.  7  and  8    shows the drawer  112  pulled out from one side of the bassinet  10 , the drawer  112  may alternatively be pulled out from the opposite side of the bassinet  10 . Although the illustrations only show the drawer front  120  on one side of the drawer  112 , the drawer  112  of the illustrated embodiment includes an identical drawer front  120  on the opposite side of the bassinet  10 . Both drawer fronts  120  have a handle  130  that can be grasped and pulled to pull out the drawer  112  from either side of the bassinet. 
     In the illustrated embodiment, the drawer  112  includes a centering arrangement that helps to maintain the drawer  112  in the centered/closed position (See  FIGS.  11 A and  11 B ). In this embodiment, the centering arrangement includes a pair of fingers  140 —one extend outwardly from the approximate center of each drawer side  122  toward the sidewalls  114 . Being affixed to the drawer sides  122 , the fingers  140  will travel along a generally linear path as the drawer  112  is opened and closed from either side of the bassinet  10 . The centering arrangement also includes two pairs of spring-loaded ball bearings  142  (e.g. ball plungers)—one pair of spring-loaded ball bearings  142  mounted in each sidewall  114  along the path of the corresponding finger  140 . On each side of the drawer  112 , the spring-loaded ball bearings  142  are mounted toward the center of the sidewall and are arranged so that the corresponding finger  140  is situated between the two spring-loaded ball bearings  142  when the drawer  112  is in the centered/closed position. For example, each pair of spring-loaded ball bearings  142  may be spaced apart just enough distance to accommodate the corresponding finger  140  there-between (See  FIG.  11 C ). Although  FIGS.  11 A-C  shows the finger  140  and spring-loaded ball bearings  142  on only one side of the drawer  112 , it should be noted than an essentially identical arrangement with a finger  140  and pair of spring-loaded ball bearings  142  is provided on the opposite side of the drawer  112 . Because the spring-loaded ball bearings  142  are positioned along the path of the finger  140 , the finger  140  must depress one of the two spring-loaded ball bearings  142  (depending on direction of travel) to move the drawer  112  out of the centered/closed position. More specifically, the drawer  112  must be moved with enough force for the fingers  140  on opposite sides of the drawer  112  to push the corresponding ball bearings into the plunger far enough for the fingers  140  to pass over the ball bearings. The amount of force required to move the drawer  112  out of the centered/closed position can be controlled, for example, by varying the spring/bias force of the ball plunger or by varying the shape of the portion of the finger  140  that interfaces with the ball bearings  142 . In the illustrated embodiment, the centering arrangement is tuned so that the force required to move the drawer  112  out of the centered position is great enough to prevent the drawer  112  from opening unintentionally while the bassinet  10  is being moved. The centering arrangement also provides the user with tactile feedback when an open drawer  112  is properly returned to the centered/closed position because each finger  140  will again have to pass over a spring-loaded ball bearing  142  as the drawer  112  is centered. 
     Also as noted above, the illustrated embodiment of the present invention includes a pullout worksurface  150  that can be pulled out from either end of the bassinet  10  (See  FIGS.  9 A-B  and  10 A-B). In this embodiment, the worksurface  150  is mounted in a cavity defined below the bassinet support surface  14  and above the dual linkage  24 . In the illustrated embodiment, the support frame  54  is configured to receive and support the pullout worksurface  150 . As shown in  FIG.  1 B , the support frame  54  includes a plurality of upper portions  154  that are configured along a common plane to collectively support the pullout worksurface  150  throughout it full range of motion. In this embodiment, the support frame  54  also includes a pair of rails  156  to support opposite longitudinal edges of the worksurface  150 . In this embodiment, the worksurface  150  is generally rectangular is substantially coextensive in length with bassinet support surface  14 , but its size and shape may vary from application to application, as desired. 
     In the illustrated embodiment, the worksurface  150  includes a stop arrangement that prevents the worksurface  150  from being pulled out too far (See  FIGS.  10 A and  10 B ). In this embodiment, the worksurface  150  includes an upwardly extending finger  158  that is positioned at the approximate center of the worksurface  150 . The finger  158  extends up into a guide slot  160  defined in the bottom of the bassinet support surface  14 . The finger  158  travels along the guide slot  160  as the worksurface  150  is pulled out and returned with further motion being prohibited once the finger  158  reaches the end of the guide slot  160 . Accordingly, the range of motion of the pullout worksurface  150  is defined by the length of the guide slot  160 . In the illustrated embodiment, the finger  158  is manufactured from a section of nylon tube, but it may be manufacture from essentially any other suitable material. 
     In the illustrated embodiment, the pullout worksurface  150  has a centering assembly that helps to hold the worksurface  150  in the closed position, which in this embodiment is also a centered position (See  FIGS.  9 A and  9 B ). The centering assembly of the illustrated embodiment includes a pair of spaced-apart spring-loaded ball bearings  162  (e.g. ball plungers) that are set into the undersurface of the bassinet support surface  14  and extend into the guide slot  160 . The ball bearings  162  are biased into an extended position in which they are positioned to interfere with movement of the finger  158  along the guide slot  160 . However, the ball bearings  162  can be moved against their bias out of the path of the finger  158  if the worksurface  150  is moved with enough force. In this embodiment, the two spring-loaded ball bearings  162  are spaced apart a distance slightly greater than the width of the finger  158 . When the pullout worksurface  150  is properly closed in the centered position, the finger  158  is positioned between the two ball bearings  162  and moving it out of the centered position requires the finger  158  to be moved through one of the two ball bearings  163  (depending on which way the worksurface  150  is being extended). To move the worksurface  150  out of the centered position, the worksurface  150  must be moved with sufficient force for the finger  158  to overcome the bias and move the ball bearing  162  into a retracted position. As a result, the ball bearings  162  help to retain the pullout worksurface  150  in the centered/closed position. Further, to return the worksurface  150  to the centered/closed position, the finger  158  must be moved through one of the two ball bearing  162  (depending on which way the worksurface is traveling), but not the other. As a result, the two spring-loaded ball bearings  162  provide tactile feedback that helps the user to determine when the pullout worksurface  150  is properly centered/closed. Although  FIG.  10 A  shows the worksurface  150  extended from one end of the bassinet  10 , the worksurface  150  may alternatively extend from the opposite end of the bassinet  10 . 
     Orienting the pullout worksurface  150  to pull out from opposite ends of the bassinet  10  prevents the extended worksurface  150  from interfering with access to the drawer  112  (as the drawer  112  pulls out from the sides rather than the ends of the bassinet  10 ). Also, because the casters are spaced apart farther in the end-to-end direction than the side-to-side, the base  11  provides more stable support for a worksurface  150  that pulls out from the end of the bassinet  10 . 
     The above description is that of current embodiments of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as defined in the appended claims, which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents. This disclosure is presented for illustrative purposes and should not be interpreted as an exhaustive description of all embodiments of the invention or to limit the scope of the claims to the specific elements illustrated or described in connection with these embodiments. For example, and without limitation, any individual element(s) of the described invention may be replaced by alternative elements that provide substantially similar functionality or otherwise provide adequate operation. This includes, for example, presently known alternative elements, such as those that might be currently known to one skilled in the art, and alternative elements that may be developed in the future, such as those that one skilled in the art might, upon development, recognize as an alternative. Further, the disclosed embodiments include a plurality of features that are described in concert and that might cooperatively provide a collection of benefits. The present invention is not limited to only those embodiments that include all of these features or that provide all of the stated benefits, except to the extent otherwise expressly set forth in the issued claims. Any reference to claim elements in the singular, for example, using the articles “a,” “an,” “the” or “said,” is not to be construed as limiting the element to the singular.