Patent Publication Number: US-9402777-B1

Title: Underarm shock absorber for crutches

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to crutches and, more particularly, to crutches with an underarm shock absorber mechanism that smoothly transmits a portion of a user&#39;s weight to the body of the crutch member. 
     2. Description of the Related Art 
     Several designs for crutches have been designed in the past. None of them, however, include an ergonomic shock absorber that comfortably conforms to a user&#39;s underarm to gradually absorb a portion of the weight of a user to be transmitted through the crutch. 
     Applicant believes that a related reference corresponds to U.S. Pat. No. 2,364,053 issued to J. Bourne for a crutch. However, it differs from the present invention because the crutch discloses a saddle member 14 that is rigid to support studs 16. This rigid engagement coacts with all springs 17 simultaneously. On the other hand, the present invention includes independent spring members that gradually absorb the weight of a user. Being independent, the spring in the present invention can be adjusted or selected to increase or decrease their compression force depending on a user&#39;s gait. 
     Similarly, in U.S. Pat. No. 1,241,815 for another crutch device, issued to Blackard, a plate 12 is shown acting on springs 13 that act simultaneously. In contrast, the present invention permits a user to apply his/her weight against the compression force of each spring independently. The characteristics of each spring are selected to present different magnitudes of spring compression forces. As the user begins to apply his/her weight, the point where the maximum portion of his/her weight to be applied is reached and then starts removing his/her weight as the user advances his/her aided step. With the prior art crutches, the entire combined spring force is presented to a user at all times resulting in an uncomfortably strong spring resistance for the beginning, during and end of a user&#39;s aided step. 
     Other documents describing the closest subject matter provide for a number of more or less complicated features that fail to solve the problem in an efficient and economical way. None of these patents suggest the novel features of the present invention. 
     SUMMARY OF THE INVENTION 
     It is one of the objects of the present invention to provide a crutch with a saddle assembly that gradually absorbs a portion of a user&#39;s weight, as needed, for minimum discomfort. 
     It is another object of this invention to provide a saddle assembly that permits a user to select the magnitude of the spring compression forces to be applied at different stages of the aided step. 
     It is yet another object of this invention to provide such a device that is inexpensive to manufacture and maintain while retaining its effectiveness. 
     Further objects of the invention will be brought out in the following part of the specification, wherein detailed description is for the purpose of fully disclosing the invention without placing limitations thereon. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       With the above and other related objects in view, the invention consists in the details of construction and combination of parts as will be more fully understood from the following description, when read in conjunction with the accompanying drawings in which: 
         FIG. 1  represents an inclined elevational view of a crutch underarm shock absorber incorporating the present invention. 
         FIG. 2  shows an inclined exploded view of the embodiment shown in  FIG. 1 , showing the different components. 
         FIG. 2A  illustrates an inclined isometric view of cylindrical actuating tube  36   a  with guiding pin  39   a  protruding outwardly. 
         FIG. 2B  shows a partial isometric view of tubular socket  42  with longitudinal slots  41 . 
         FIG. 2C  is a cross-sectional view showing the disposition of tubular socket  42   a  with actuating tube  36   a  and spring member  47   a  housed therein and guiding pin  39   a  guided within slot  41 . 
         FIG. 3  is a partial cross-sectional representation of truss  20 , saddle assembly  30  and support assembly  40 . 
         FIG. 3A  is similar to  FIG. 3  except that cushion  133  is continuously covering movable plates  31   a ;  31   b  and  31   c.    
         FIG. 4  is an exploded view showing the different components of underarm shock absorber  10 . 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS OF THE INVENTION 
     Referring now to the drawings, where the present invention is generally referred to with numeral  10 , it can be observed that it basically includes arm truss assembly  20 , saddle assembly  30  and supporting assembly  40 . Underarm shock absorber for crutches  10  is rigidly mounted to crutch stick S, substantially perpendicularly thereto. 
     Arm truss assembly  20  includes ends  21  and  24 . Assembly  20  extends a predetermined distance, substantially straight, as seen  FIG. 1 . In one of the preferred embodiments, such as the one illustrated in these figures, truss assembly  20  includes five through openings  26   a  through  26   e , as best seen in  FIG. 2 . In this application, the use of letter subscripts denotes specific components. If no subscripts are used it will be understood to relate to similar components addressed in general. Also, through holes  27   a  through  27   d , four of them in this embodiment, are located between adjacent through openings  26   a  through  26   e . Truss assembly  20  is made out of a rigid material, and preferably light, such as aluminum. Elongated concave support assembly  40  is substantially coextensive with truss assembly  20  and includes through apertures  28   a  through  28   d  that are cooperatively aligned with holes  27   a  through  27   d . In the preferred embodiment shown in these drawings through apertures  28  include sockets  128   a  through  128   d  for receiving nuts  129   a  through  129   d . Bolts  23   a  through  23   c  pass through through holes  27   a  through  27   d  and through through openings  28   a  through  28   d  to be matingly received by nuts  29   a  through  29   d.    
     Supporting assembly  40  longitudinally receives truss assembly  20 . Sockets  42   a  through  42   e  are perpendicularly mounted to the concave side of assembly  40  and have cooperative dimensions to pass trough through openings  26   a  through  26   e  and protruding through truss member  21  a predetermined distance. These components can be best seen in  FIG. 4  with tubular sockets  42   a  through  42   e  having slots  41   a  through  41   e.    
     Saddle assembly  30  is seen in  FIG. 1  to have an ergonomic shape. As seen in  FIG. 2 , saddle assembly  30  includes supporting plates  31   a  through  31   e  (five of them in the embodiment shown in  FIG. 2  of this application) that extend longitudinally a predetermined distance that substantially corresponds with the length of truss assembly  20 , in one of the preferred embodiments. The undersides  131   a  through  131   e  of plates  31   a  through  31   e  include posts  32   a  through  32   e  that are rigidly mounted to, or integrally extend from, undersides  131   a  through  131   e , as best seen in  FIGS. 3A and 3B . Preferably, threaded holes  34   a  through  34   e  are centrally located to receive screws  35   a  through  35   e  (or equivalent fastening members). Actuating cylindrical tubes  36   a  through  36   e  are in turn abuttingly mounted, at one end, to the distal end of posts  32   a  through  32   e . Tubes  36   a  through  36   e , in turn, have cooperative dimensions to actuate (compress) spring members  47   a  through  47   e , as it will be discussed below. 
     Supporting assembly  40 , as seen in  FIGS. 1, 1A and 2 , also extends a predetermined distance that is substantially the same as the length of arm truss assembly  20  and plates  31   a  through  31   e . Assembly  40  has a longitudinally extending concave upperside that cooperatively receives truss assembly  20 . In one of the preferred embodiments, assembly  40  is a partially longitudinal half of a tube with a semi-circular cross-section having an internal diameter that substantially matches the outer diameter of truss assembly  20 . Assembly  40  includes five spaced apart tubular sockets  42   a  through  42   e  that cooperatively partially receive cylindrical actuating tubes  36   a  through  36   e , as best seen in  FIG. 2 . Spring members  47   a  through  47   e  are completely housed within tubular sockets  42   a  through  42   e , as best seen in  FIGS. 3 and 3A . Sockets  42   a  through  42   e  include longitudinally extending slots  41   a  through  41   e  that receive outwardly guiding protrusions  39   a  through  39   e  of tubes  36   a  through  36   e . Protrusions  39   a  through  39   e  of tubes  36   a  through  36   e  are cammingly inserted into sockets  42   a  through  42   e  causing a slight deflection of sockets  42   a  through  42   e  as well as tubes  36   a  through  36   e  until protrusions  39   a  through  39   e  reach guiding slots  41   a  through  41   e . Once protrusions  39   a  through  39   e  are lodged inside slots  41   a  through  41   e , the axial movement of tubes  36   a  through  36   e  is limited between two extreme positions. Spring members  47   a  through  47   e  are coaxially housed within sockets  42   a  through  42   e , as best seen in  FIGS. 3 and 3A . Spring members  47   a  through  47   e  can be selected with different compression constant magnitudes depending on a user&#39;s preference. For example, a user may prefer to have a softer initial approach pressure under his/her arm than on exiting, or he/she may have a more sensitive area of his/her body. Also, a heavier user may require more compression force on spring members  47   a  through  47   e  than a person with less weight. Tube  36   a , socket  42   a  and spring member  47   a  can be best seen in  FIGS. 2A ;  2 B and  2 C. Tubes  36   a  through  36   e  include, in one of the embodiments, frustoconical end ends  38   a  through  38   e  to facilitate the engagement with counterbored ends  132   a  through  132   c  (the counterbore ends for posts  32   d  and  32   e  are not shown) having centrally located and axially extending threaded holes  34   a  through  34   e . Screws  35   a  through  35   e  fasten tubes  36   a  through  36   e  to posts  32   a  through  32   e . Posts  32   a  through  32   e  extend from undersides  131   a  through  131   e  to coact with the upper end of tubes  36   a  through  36   e  transmitting a portion of a user&#39;s weights applied to plates  31   a  through  31   e . Cushions  33   a  through  33   e  are mounted to plates  31   a  through  31   e  to provide a soft and comfortable contact area with a user&#39;s underarm as shown in  FIG. 3 . Optionally, a continuous cover  133  is mounted over cushions  33   a  through  33   e . Cover  133  is preferably made of an hypoallergenic material to minimize irritation to a user&#39;s underarm. In use, a user will apply a substantial portion of his/her weight to his/her underarm area that will conform to his/her preferences. 
     The foregoing description conveys the best understanding of the objectives and advantages of the present invention. Different embodiments may be made of the inventive concept of this invention. It is to be understood that all matter disclosed herein is to be interpreted merely as illustrative, and not in a limiting sense.