Abstract:
A pole member for a stand, such as a medical stand, is defined by a first pole section and a second pole section. The first pole section includes a hollow end having a spline disposed therein for engaging a corresponding spline formed on a mating end of the second pole section. The splines are sized to interconnect wherein each spline includes tapering teeth and slots to create locking engagement therebetween and limit lateral play. A locking element engages the hollow end of the first pole section when inserted a predetermined distance therein.

Description:
FIELD OF THE INVENTION 
       [0001]    The application relates generally to the field of assembled articles and more specifically to a coupling assembly for assembled articles, such as a supporting pole assembly for a medical mobile stand. 
       BACKGROUND OF THE INVENTION 
       [0002]    Many articles are shipped to their end destinations in a fully assembled condition. Shipping containers for these articles therefore must be quite large; particularly for assemblies that are defined by relatively long or bulky portions. To ease shipability, some articles are transported in component or part form wherein final assembly is completed by an end user. Certain of these articles, such as stands and the like that include posts or poles among their component parts, are among such assemblies that could be shipped in a partially assembled state. In some versions, these poles are made to be telescopic to aid in assembly or in permitting adjustability using a smaller initial footprint. A competing issue exists, however, in that some assemblies may also have stability requirements. It is still a desire to be able to ship or initially store such articles in order to decrease the size of their respective shipping container, but yet permit dependable secure assembly of the discrete components, for example, in a permanent structure. 
       SUMMARY OF THE INVENTION 
       [0003]    Therefore and according to one aspect, there is provided a support assembly comprising a pair of interlocking pole members; namely, a first pole member having a hollow end with a female spline disposed therein for mating engagement with a male spline formed at the end of a second pole member. The engaging teeth of the male and female splines combine to define an interface that directly and permanently engages the pole members and minimizes lateral play. In one version, the teeth are angled to create an interference fit. 
         [0004]    In one version, the hollow end of the first pole member includes a contoured mating hole sized to receive an extending portion of the second pole member. 
         [0005]    In another version, a concave washer with a serrated edge or other locking element engages the hollow end of said first pole member when the second pole member is inserted a predetermined distance into the hollow end of the first pole member. 
         [0006]    According to one version, the teeth and the slots of the respective splines are tapered but in which the teeth of the male spline are larger than the corresponding tapered slots of the female spline, thereby producing line contact and a stable and secure interconnection. 
         [0007]    According to another aspect, there is provided a mobile stand, said mobile stand comprising a wheeled base and a vertically extending pole member in which each of the pole member and wheeled base are interconnected, the pole member having a first spline and the wheeled base having an extending mating section that includes a second spline. The first and second splines interface to form a permanent connection. The vertically extending pole member can be made from two or more separate and interlocking sections, each of the interlocking sections being defined by respective mating ends. 
         [0008]    The interlocking sections are defined by a first pole section having a hollow end with a female spline disposed therein for mating engagement with a male spline formed at the end of a second pole section. The engaging teeth of the male and female splines combine to define an interface that directly and permanently engages the pole sections and minimizes lateral play. In one version, the teeth are angled to create an interference fit. 
         [0009]    According to yet another aspect, there is described a method for manufacturing a pole assembly, said method including the steps of providing a first pole section with a hollow first end having a first spline, providing a second pole section having a first end and providing a second spline complementary to said first spline at said end. One of said splines of the first and second poles includes a plurality of axial teeth and the other of said splines includes a plurality of slots, each of said slots being sized to receive said teeth in an interference fit. 
         [0010]    An advantage is that sturdy, stable and reliable assembly is made possible using the herein described stand, while still permitting portions thereof to be shipped as component parts. 
         [0011]    Another advantage is that the assembly process is relatively easy, while still being permanent and secure. 
         [0012]    These and other features and advantages will be readily apparent from the following Detailed Description, which should be read in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a front perspective view of a mobile stand including a pole assembly made in accordance with an exemplary embodiment of the present invention; 
           [0014]      FIG. 2  is an assembly view of the pole assembly, partly in section used in the mobile stand depicted in  FIG. 1 ; 
           [0015]      FIG. 3  is an assembled view of the pole assembly of  FIG. 2 , shown in section; and 
           [0016]      FIG. 4  is a sectioned partial side elevational view illustrating the interconnection of a pole member to the wheeled base of the mobile stand of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    The following description relates to an exemplary mobile stand depicting salient features of the present invention. More specifically, the mobile stand includes a pole assembly made in accordance with the inventive concepts defined herein. It will be readily apparent, however, that various modifications and/or changes could be made within the intended scope of the concepts that are described herein. In addition, certain terms such as “upper”, “lower”, “distal”, “proximal”, “above”, “below” and the like are used throughout the course of this description in order to provide a convenient frame of reference with regard to the accompanying drawings. These terms, however, are merely intended to provide clarity and not to narrow the scope of the claimed invention, except where so specifically indicated. 
         [0018]    Referring to  FIG. 1 , there is shown a mobile stand  20  defined in accordance with an exemplary embodiment. The mobile stand  20  is defined by a wheeled base  24 , which includes a plurality of wheels  27  extending from the bottom of a set of base legs  26 , the wheels being rotatably secured thereto by casters  28  or other suitable means. In this version, five (5) base legs and wheels are shown, although this parameter can be easily and suitably varied. The base  24  further includes a center stanchion or post  29  having a hollow end  100  that is sized to receive one end of a support pole member  30 . As described herein, the support pole member  30  is made of a pair of interlocking pole sections; namely a lower pole section  34  and an upper pole section  38  that are assembled together into a unitary member, as a subassembly. 
         [0019]    A medical instrument, such as a vital signs monitoring device  44 , (such as a SPOT ULTRA monitoring device sold by Welch Allyn, Inc. of Skaneateles Falls, N.Y.), is attached by known means to the upper end of the upper pole section  38  in addition to other hardware, including a support basket  48 . The herein shown vital signs monitoring device  44  is configured to measure various physiological parameters of a patient (not shown) including, but not limited to body temperature, blood pressure, respiration, pulse rate and blood oxygen saturation (pulse oximetry). Other instruments/devices can be used depending on the application, wherein the instrument shown is herein intended to be merely exemplary. The support basket  48  is secured to the upper pole section  38  by means of a bracket  52 , which is attached to the exterior of the upper pole section by a set of fasteners  56  or other convenient means. Alternatively, the support basket  48  could be made integral with the upper pole member  38 . The support basket  48  according to this embodiment is used to conveniently store accessories (not shown) for the attached monitoring device  44 , such as thermometry probe covers, inflatable blood pressure cuffs and the like. Other suitable storage or securing means such as hooks can also be provided, depending on, for example, the instrument and application of the mobile stand  20 . 
         [0020]    The mating interface of the two interlocking pole sections  34 ,  38  of the pole member  30  according to this exemplary embodiment is now described in greater detail with reference to  FIGS. 2 and 3 . 
         [0021]    According to this embodiment, the upper end of the lower pole section  34  is hollow and includes a contoured female mating hole or opening  60 , which further includes an insert section  64 , the diameter of the mating hole being narrowed at a lower end  68  of the insert section. A female spline  72  is formed within an axial portion of the insert section  64  proximate the opening  60 . The female spline  72  is defined by a series of axially extending slots  74  disposed about the inner circumference of the insert section  64  proximate the hollow upper end of the lower pole section  34 . Each of the slots  74  taper inwardly from a larger width dimension adjacent the opening  60  to a narrower width dimension at a bottom end. Each slot  74  is bounded by a sidewall projecting radially from the spline  72 , the slots being separated from one another by annular sections  77 . 
         [0022]    Still referring to  FIGS. 2 and 3 , the lower end of the upper pole section  38  includes mating features that are complimentary to those provided in the lower pole section  34 . To that end and according to this exemplary embodiment, a male spline  80  is provided at the lower end along an axial portion of the pole section  38 . The male spline  80  is defined by a plurality of axially extending teeth  84  formed about the entire outer circumference of the upper pole section  38 . The teeth  84  extend axially; that is, in a direction that is parallel with the primary axis of the upper pole section  38  wherein each tooth preferably includes a pair of sidewalls that taper outwardly from a distal end  87  to a proximal end  86  of each tooth. The outward taper of the teeth  84  of the male spline  80  is slightly larger than the taper defined by the slots  74  of the female spline  72 . The teeth  84  are equally spaced about the circumference of the axial portion of the upper pole section  38 , each of the teeth being separated by annular sections  85 . 
         [0023]    Coextensive with the lower end of the upper pole section  38  is an extending cylindrical section  88  that is distally arranged relative to the male spline  80 . The extending cylindrical section  88  extends over an axial section of the pole section  38  and has a diameter that is narrower than the outer diameter of either spline  72 ,  80 . The cylindrical section  88  includes a distal section having a center opening (not shown), aligned along the primary axis of the pole section  38 . This center opening according to this embodiment is threaded and configured to receive a fastener  96 . The fastener  96  is used to secure a locking washer  92  to the distal end section of the upper pole section  38 . The locking washer  92  is defined by a concave shape, including a plurality of serrated portions  98  that are circumferentially disposed. 
         [0024]    When the lower and upper pole sections  34 ,  38  are assembled together as shown in  FIG. 3 , the extending cylindrical portion  88  of the upper pole section  38  is sized to fit within the opening  60  of the insert section  64  and be advanced axially into the lower portion  68  thereof. As the upper pole section  38  is advanced axially, the teeth  84  of the male spline  80  engage the tapered slots  74  of the female spline  72  without interference between the annular sections  77 ,  85 . The male and female splines  72 ,  80  defined herein together define a mating interface such that when the teeth  84  of the male spline  80  engage the slots  74  of the female spline  72 , the outward taper of the male teeth  84  being slightly larger than that of the slots  74  of the female spline  72  creates line-contact made between each mating tooth. As engagement increases axially, coupler material is slightly displaced to create surface to surface contact, which increases overall interface effectiveness. 
         [0025]    The foregoing interface between the engaging splines  72 ,  80  of the engaged pole sections limits lateral play as well as radial motion between the mating upper and lower pole sections  34 ,  38 . In addition, a diametrical interface is provided between the extending cylindrical portion  88  and the mating hole  66  distal to the splines  72 ,  80  that further limits lateral play between the two pole sections  34 ,  38 . 
         [0026]    In addition, the locking washer  92  further acts to engage the upper and lower pole sections  34 ,  38  together in a locking relationship. As noted, the locking washer  92  is affixed to the distal neck or end of the upper pole section  38  by means of a fastener  96 , such as a screw, bolt or other threaded fastener. The orientation of the locking washer  92  is such that the insertion of the upper pole section  38  into the mating hole  60  of the lower pole section  34  is unidirectional. The diameter of the locking washer  92  is greater than the narrowed diameter of mating hole  68  and therefore the sharp edges of the serrated sections  98  penetrate the inner diametrical wall of the insert portion  64  as the upper pole section  38  is axially inserted into the lower pole section  34 . The natural concave shape of the locking washer  92  prevents removal from the lower pole section  34 , thereby preventing the mating pole sections  34 ,  38  from being separated and permanently locking them in direct engagement. 
         [0027]    Referring to  FIG. 4 , the lower end of the lower pole section  34  and the wheeled base  24  of the herein described mobile stand  20  also can be assembled using a secured locking assembled arrangement akin to that depicted in  FIGS. 2 and 3 . Similar parts are herein labeled with the same reference numerals for the sake of clarity. In this instance, the lower end of the lower pole section  34  includes an arrangement similar to that of the lower end of the upper pole section  38 ,  FIG. 2 . That is, the lower pole section  34  includes a male spline  80  having a series of axially disposed and tapered teeth, an adjacent distal extending cylindrical section  88  and a locking washer  92  attached to a distal neck or end of the pole section, respectively. 
         [0028]    According to this exemplary embodiment, the wheeled base  24  includes a hollowed vertically extending shaft  102  that is provided within the center stanchion  29  of the base. This shaft is defined by a mating hole or opening  106  that is sized to receive the lower end of the lower pole section  34 , the shaft further including a complementary female spline  110 . The opening  106  of the extending shaft  102  is contoured and is defined by a diameter that decreases or narrows in relation to the open end thereof. Preferably, the male spline  80  includes a set of axially extending teeth  84  that are tapered along their length, like those previously discussed and shown in  FIGS. 2 ,  3  for engagement within complementary tapered slots formed within the female spline  110 . As in the preceding, axial engagement of the lower end of the pole section  34  into the mating hole  106  of the base shaft  102  causes the extending section  88  of the pole section end to engage therewith, including the locking washer  92 , the latter being permanently secured to the extending section  88  by a threaded fastener  96  that is attached to the distal neck, the locking washer including a plurality of serrated portions that each engage the interior diametrical wall of the shaft  106  when the pole section  34  is axially engaged with the base  24 . The engagement between the splines  72 ,  80 , reduces lateral play wherein the pole section  34  becomes permanently and stably secured to the base  24 . 
       PARTS LIST FOR FIGS.  1 - 4   
       [0000]    
       
           20  mobile stand 
           24  base 
           26  base legs 
           27  wheels 
           28  casters 
           29  center stanchion or post 
           30  support pole member 
           34  lower pole section 
           38  upper pole section 
           44  medical instrument 
           48  support basket 
           52  bracket 
           56  fasteners 
           60  mating hole or opening 
           64  insert portion 
           68  mating hole, narrowed 
           72  female spline 
           74  slots 
           77  annular sections 
           80  male spline 
           84  teeth, tapered 
           85  annular sections 
           86  proximal end 
           87  distal end 
           88  extending cylindrical section 
           92  serrated locking washer 
           96  fastener 
           98  serrated sections 
           102  hollowed shaft 
           106  mating hole or opening 
           110  female spline 
       
     
         [0060]    It will be readily apparent that other modifications and variations are possible that include the inventive concepts according to this application. For example, it should be noted that the splines could be reversibly located; that is, the male spline could be situated on the lower pole section and the female spline situated along the upper pole section of the pole member.