Abstract:
The present invention provides a knee joint including a joint top, a connection device, a cushion device, a resilient device, and a pneumatics joint body. The joint top and joint body are respectively joined to a thigh and a shank. With the cushion components including a connector and a connector, in the operation of kicking and swinging of leg in walking, standing, sitting, and kneeling, the angle between the connector and the connector support is changed to allow the knee joint to stay in a stable position and further preventing the shank from falling and/or kneeling during a walking operation and further effecting shock absorption by the cushion device at the time when the knee joint bends in walking along a slope, or setting the bending position of the knee joint with change of pressure applied to protect the user from the risk of abrupt kneeling.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    (a) Technical Field of the Invention 
         [0002]    The present invention relates to a retention and cushion structure of a knee joint, and in particular to knee joint shock absorption structure that may absorb impact forces by setting a connector and a connector support at a predetermined range of bending angle when the knee joint carries out actions. 
         [0003]    (b) Description of the Prior Art 
         [0004]    Medical technology and therapeutics are increasingly improved day by day and the disabled can be offered with increased moveability of walking through prosthetic devices, together with proper rehabilitation. The prosthetic device or artificial joint is often of a mechanical structure, which should be of a design that to the best extent mimics the action and configuration of human joints and should be set in the attempt to simulate the design of natural joint of human being in both shape and size to best satisfy the walking capability offered by the nature. 
         [0005]    The convention artificial joint, as being pointed out in the disclosure of Taiwan Patent Publication No. 549074, is constructed in such a way that an upper end of the knee joint is formed to join to the tight of a disabled person and a lower end thereof connected to a shank and foot. Such a construction is generally formed of a compound linkage to provide the effect of simulating the natural knee joint and the lower link is provided with a cushion pad. When an upper acting link and a cushion link arranged at lower side are put in a line-like inward orientated direction, a drawback in operation of the known device is clearly observed, which will be explained as follows. 
         [0006]    When the known knee joint is put into contact with ground in a straight stretching condition and thus receives an impact force, although the acting link may abut against the cushion pad to effect absorption of the impact force acting in the direction of the foot, yet the shock absorption function thereof can only be effected in the condition that the foot and the knee joint are substantially put in a line. For walking on a horizontal surface, the knee joint can be put onto contact with the ground in a substantially right-angle posture by properly lifting the leg to effect shock absorption. However, when walking in a downhill slope, to put the foot onto the ground in a natural way of walking, the knee joint has to be presented in small angle bending under which condition the known device apparently is not effective in fully exploiting the shock absorption capability thereof. Further, the links cannot be set and retained so that walking on slope may lead to the risks of abrupt bending or kneeling of the knee joint and inconvenience of walking in a slope for the disabled. 
         [0007]    Thus, the present invention is aimed to improve the cushion structure of the conventional knee joint in order to present more natural way of walking through the knee joint cushion device of the present invention. 
       SUMMARY OF THE INVENTION 
       [0008]    In view of the above discussed drawbacks of the conventional prosthetic knee joints, the present inventor recognizes that with the poor effect of cushioning and shock absorption provided by the conventional knee joints, shock absorption effected by the cushion device of the knee joint cannot be fully exploited in walking in a slope, often leading to dangerous actions of abrupt downward bending or kneeling, and attempts to provide an improved kneel joint structure to effectively realize retention, cushioning, and shock absorption in walking and standing. It is also expected that the present invention may benefit the limb-disabled. Thus, the present inventor, based on the years&#39; experience and devotion to the development of artificial limbs and prosthetic devices, creates the knee joint having retention and cushion structures that will be further discussed herein as the subject invention of the application. 
         [0009]    An objective of the present invention is to provide a knee joint with retention and cushion structures, wherein when the knee joint bends rearward to carry out kicking and swinging of shank in walking or the knee joint is in standing, the angle of a connector is changed by load to abut against a connector support to set the knee joint at a stable position and protecting the shank from risks of falling or kneeling and, in addition, when walking in a slope, the angle of the knee joint after bending allows the cushion device to effect cushioning, and further, the knee joint can be changed by load to a stable position of angled bending to protect a user from the risk of kneeling down. 
         [0010]    To achieve the above objective, the present invention provides a knee joint with bending cushioning structure, which comprises in construction, a joint top, a connection device (including two curved plates and a connector), a cushion device (including a connector support and a pneumatic cylinder), a resilient device (including spring pistons and springs), and a pneumatics joint body, which are assembled together with threaded connection. The joint top functions to join to a thigh located thereabove, and the pneumatics joint body that is located below is to connect to a shank and a foot therebelow. By means of the arrangement of cushion components on the connector support, the knee joint is provided with two fixed returning points, which allows the knee joint to effect bending, while in kicking and/or swinging of shank of walking and/or in standing, no excessive swinging is allowed between a connector and the connector support to exhibit a fixed stable condition, and which allows the installed knee joint to walk stably and allows the cushion device to effect cushioning and shock absorption by means of the rearward bending angle of the knee joint when walking in a slope to thereby make the disabled walking in a more comfortable and natural manner. 
         [0011]    The foregoing object and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts. 
         [0012]    Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is an exploded view of the knee joint constructed in accordance with the present invention; 
           [0014]      FIG. 2  is a perspective view of the knee joint of the present invention in a partially assembled condition; 
           [0015]      FIG. 3  is a cross-sectional view of the knee joint of the present invention illustrating the knee joint at a give position; 
           [0016]      FIG. 4  is a side elevational view of the knee joint of the present invention at the give position; 
           [0017]      FIG. 5  is a side elevational view of the knee joint of the present invention illustrating the knee joint is moved to another position; 
           [0018]      FIG. 6  is a cross-sectional view of the knee joint of the present invention at said another position; 
           [0019]      FIG. 7  is a side elevational view of the knee joint of the present invention illustrating the knee joint is moved to a further position; 
           [0020]      FIG. 8  is a cross-sectional view of the knee joint of the present invention at said further position and demonstrating cushion effect of the knee joint; 
           [0021]      FIG. 9  is a side elevational view of the knee joint of the present invention illustrating the knee joint is moved to yet a further position; 
           [0022]      FIG. 10  is a cross-sectional view of the knee joint of the present invention at said yet a further position and demonstrating cushion effect of the knee joint; 
           [0023]      FIG. 11  is a side elevational view of the knee joint of the present invention illustrating the knee joint is moved to yet another further position; and 
           [0024]      FIG. 12  is a cross-sectional view of the knee joint of the present invention at said yet another further position and demonstrating cushion effect of the knee joint. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0025]    The following descriptions are of exemplary embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims. 
         [0026]    The present invention relates to a knee joint with retention and cushion structures, which comprises, in construction, a joint top  10 , a connection device (including curved plates  30  and a connector  20 ), a cushion device (including a connector support  40  and a pneumatic cylinder  51 ), a resilient device (including spring pistons  52  and springs  53 ), and a pneumatics joint body  50 , which are assembled by threading connection. The joint top functions to join to a thigh located thereabove, while the pneumatics joint body that is located below is to connect to a shank and a foot therebelow, wherein: 
         [0027]    the joint top  10  has two projecting flange wings  11  extending from one side of a disk surface thereof and also forms an inwardly recessed opening that is between the two projecting flange wings and that is inwardly inclined and a semi-circular slot formed above the inwardly recessed opening to allow the inclined face to mate and join the connector  20  of the connection device, and the two sideway located projecting flange wings  11  of the knee top each form a through hole  12 , so that with the connector forming, at a location corresponding to the inclined face of the inwardly recessed opening of the joint top, an inclined face for abutting purposes, and with the connector forming, at an upper portion thereof, an upper through hole  21  for joining, in an embedded manner, the joint top and received in the inwardly recessed opening of the joint top, the joint top and the connector each is provided with a resilient block  14  arranged on the inclined face thereof for abutting engagement and are jointed together as a unitary device by sideway fitting roller bearings  60  in the through holes of the projecting flange wings of the joint top and extending a shaft  13  through the upper through hole of the connector; 
         [0028]    the block that constitutes the connector  20  forms, at a lower portion thereof, another, lower through hole  22  that is received between and connected with rounded dome projections  41  extending from opposite sides of an upper end of the connector support  40 , and also forms, at a front side thereof, two lugs  23  defining at centers thereof connection through-holes  24  and receiving therebetween an inverted Y-shaped pneumatic cylinder driving rod  513  with a pin  25  extending therethrough to connect the pneumatic cylinder driving rod that contains therein a roller bearing  61  and the pneumatic cylinder driving rod is further coupled to a piston-rod joint  511  of a piston rod  512  of the pneumatic cylinder  51  that is concealed in the joint body  50 , wherein the coupling between the connector and the connector support is provided by a pin  26  connecting through holes  42  defined in the sideways-located dome projections of the connector support and the lower through hole of the connector in which a needle bearing  60  is contained; 
         [0029]    the connector support  40  is arranged in a cavity defined between extension wings  54  of the pneumatics joint body  50  and is provided, at a location below the dome projections thereof, with a through bore  43  that is in alignment with through holes  55  defined in the extension wings with a shaft  44  extending through the holes  55  that contain needle bearings  60  therein for engagement with the through bore so as to couple the connector support and the pneumatics joint body together, wherein the dome projections are put in abutting engagement with the spring pistons  52 , so that the connector support can be subjected to constraints imposed thereon by the connector to have the dome projections abutting against the spring pistons by threadingly mounting an adjusting bolt  45  to a lower portion thereof and having the adjusting bolt  45  abutting against the joint body, causing compression of the springs  53  arranged below the spring pistons, which maintains the spring pistons in a resiliently biased condition to engage the connector support, whereby the connector support is resiliently supported and thus having cushion function; and 
         [0030]    the pneumatics joint body  50  that is arranged at a lower side to connect to a shank and a foot therebelow is provided with the pneumatic cylinder  51  of the cushion device and joint-body tubular members  56  each having an open end closed and locked by a spring adjusting bolt  57  and an opposite open end into which the spring  53  and the spring piston  52  are fit so as to fix on the joint body, with the spring piston abutting against the connector support  40 , and the joint body is provided in a symmetric manner at opposite sides thereof with through holes  58  in which needle bearings  60  are respectively received with an internally-threaded tube  59  extending through central bores of the needle bearings, and each curved plate  30  of the connection device is fixed, at one end thereof, to the internally-threaded tube by a hexagon socket bolt  62  and is also fixed, at an opposite end thereof, in the similar way to an internally-threaded tube that is fit into a central bore of a needle bearing mounted in a through hole  15  defined in one side face of the joint top  10  by a hexagon socket bolt, allowing the curved plate to rock along with the bending action of knee joint, whereby a knee joint cushion structure, which is particularly illustrated in the cross-sectional view of  FIG. 3 , is thus constructed by assembling the above-described components. 
         [0031]    With reference now to  FIG. 3 , the assembling and operation of the components of the present invention will be described. By following the above described process, the connector  20  is matingly fit into the inwardly recessed opening of the joint top  10 . The resilient block  14  is disposed on the inclined surface of the inwardly recessed opening. The piston-rod joint  511  is mounted to the piston rod  512  of the pneumatic cylinder  51  that is arranged inside the joint body and the inverted Y-shaped pneumatic cylinder driving rod  513  is fit so that the pneumatic cylinder driving rod is located between the lugs  23  of the connector and is secured by the roller bearing  61  and the pin  25  and the lower through hole of the connector is aligned with the through holes  42  of the dome projections  41  that are located on opposite sides of the connector support with the pin extending therethrough. The lower through hole  43  of the connector support cooperates with the shaft  44  to joint with the through holes  55  defined in the extension wings  54  of the pneumatics joint body. The through hole  15  that is defined in the joint top and the through hole  58  of the pneumatics joint body, after having been fit with the needle bearings and receiving the internally-threaded tubes therein, are jointed to each other by the curved plates  30  on the opposite sides and are secured by the flat-headed hexagon socket blots  62 . The pneumatics joint body forms, at a lower edge thereof, an internally recessed bore for jointing the shank and the foot and the internally recessed bore is provided with threading for being jointed with a bolt for fixing purposes. The spring pistons  52  arranged on the joint body are put in abutting engagement with the dome projections  41  of the connector support and the spring forces of the resilient device are adjusted by means of the spring adjusting bolts  57  that threadingly engage the ends of the tubular members  56  and adjusting screws  46  of the connector support. 
         [0032]    The connector support  40 : in case that a user is standing, the connector support is subject to load and downwardly depresses the springs of the resilient device to timely effect cushioning so as to make the user of a prosthetic device feel more comfortable. 
         [0033]    Valve adjusting screw  514 : the adjusting screws function to change gas flowrate inside the pneumatic cylinder to thereby effect adjustment of the speed of bending and stretching of the joint. 
         [0034]    Referring to  FIGS. 4-12 , an operation of bending that is most preferably performed by the structure of the present invention will be described with reference to the drawings to explain the assembling of various components of the present invention with demonstration with simple steps, reference numerals being adopted the same as those shown in  FIGS. 1-3 . 
         [0035]    As shown in  FIGS. 4-12 , the first step is a bending operation that the knee joint bends from a small angle to a large angle; 
         [0036]    When the knee joint bends as the condition illustrated in  FIGS. 5 and 6 , where the joint top  10  is slightly bent to an angle of eight degrees, the connector  20  and the connector support  40  are subjected to a force of downward loading, causing a connection point between the connector and the joint top to displace downward and the connector support exhibiting a condition of downwardly depressing the tubular members  56  thereby effecting cushioning function; when the knee joint bends a greater angle, as illustrated in  FIGS. 7 and 8 , the joint top takes a condition of 62 degrees, where the curved plates  30  of the connection device are substantially parallel to the joint top, in which condition the pressures applied to the knee joint is the greatest and the connector  20  depresses the piston rod  512  to the lowest point. In a case that the joint top does not reach a 90-degree bent condition, the joint top under the above described bending situation, is subject to support by the pneumatic cylinder of the cushion device, as well as being abutted against and supported by the resilient device whereby the joint top of the knee joint can automatically return to a regular standing condition as illustrated in  FIG. 4 . Since the knee joint does not need to bend to a 90-degree condition in regular walking, the connector and the connector support, when performing kicking and swinging in doing a regular walking or standing, do not need to induce an excessive swinging therebetween and thereby exhibiting a fixed condition whereby risk of abrupt bending down or kneeling down occurring in the knee joint connector, when performing walking along a slope, can be eliminated. The knee joint can facilitates walking in a stable manner and can allow the cushion device to effect cushioning and shock absorption by means of the angle of bending of the knee joint in walking along a slope. 
         [0037]    Also referring to the illustration of  FIGS. 9 and 10 , which demonstrate bending of the knee joint for further explanation of the present invention, as shown in these drawings, the knee top  10  is bent to 90 degrees, which allows a user to stably sit on for example a chair as an ordinary person, and the curved plates  30  are new located between the upper and lower through holes  21 ,  22  of the connector whereby when a force is applied to cause the bending of the joint top to become less than 90 degrees, the joint top of the knee joint, due to the support of the pneumatic cylinder of the cushion device and the abutting support by the resilient device, is automatically returned to the regular standing posture illustrated in  FIG. 4  and when a force is applied to make the bending of the joint top exceeding 90 degrees, similarly due to the action of the cushion device and the resilient device, the inclined faces of the joint top and the connector, which are originally abut against each other, are changed by the rotation angle of the connector to such a condition that the inclined face is now in abutting engagement with a rounded top face of the connector so as to allow the joint top to bend toward another fixing point and the curved plates of the connection device is now moved to a location corresponding to the connector support, as illustrated in  FIGS. 11 and 12 , whereby the joint top is allowed to bend an angle of 150 degrees and the user is thus allowed to kneel down for carrying out on-ground operations by means of the bending of the knee joint. It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above. 
         [0038]    While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention.