This invention generally relates to a part to be used with a lanyard suspension system, such as a lanyard suspension system for a prosthetic limb socket assembly. The part stores excess lanyard cord extending from the outer socket. The present invention may be used for the system described in application Ser. No. 11/111,483; however, it may be used with any lanyard ravel system, and it may also be used to retain cord for any device.
In an exemplary embodiment, a lanyard cord retainer spool is provided, which may be mounted onto the side of a prosthetic limb socket to retain slack or excess cord from a lanyard locking system. After the limb has been locked into place, excess cord from the lanyard system may be pressed into a seam formed between the outer wall of the prosthetic limb socket and a radially outer flexible sealing flange of the cord spool to enter a circumferential channel of the cord spool (radially between the outer flexible sealing flange and an inner stem), and may be manually wrapped around the stem of the spool in a circular motion.
The cord retainer spool is formed to allow a cord to easily slip into the housing unit into a channel defined by the cap, stem and the lip, and coil around the stem. The cord retainer spool provides resistance to securely hold the cord and resist self-unraveling, but allows the user to disengage the cord from the cord retainer spool and uncoil it. The end of the cord is left out the cord retainer.
The cap and stem are generally circular to maximize winding speed and storage capacity, and are generally concentric to each other. The cap is convex, and the edges curve toward the inner surface. The cap has an angled lip around the perimeter to allow the cord to enter the seam, but provides greater resistance so the cord is secured and does not unravel out from the housing unit. A hole may be drilled through the solid stem to attach onto the socket.
In an exemplary embodiment, referring to
The cord retainer spool 10 may be formed from an elastomer with a durometer of between 50 A and 100 A, for example 80 A; however, alternative flexible materials may be suitable for the intended purposes described herein. Referring to
The channel 35 formed between the inner side 30 of the cap 15 and the socket wall 70, and defined by the stem 25 and the flange 40 provides room to store the cord 74 therein as it may be manually wrapped around the stem 25. The cap 15 covers and protects the cord from view, and the cap 15 and flange 40 bias against the cord 74 passing between the flange 40 and the socket wall 70, thereby retaining the wound cord 74 within the cord retainer spool 10.
The stem 25 in the hub of the cord retainer spool 10 provides a structure around which to wind excess cord 74. It is designed with a large diameter to minimize the number of winds needed to store the excess cord. In an exemplary embodiment, this diameter may be between about 25% and 75% of the diameter of the cap 15; and in an even more detailed embodiment, this diameter may be about 50% of the diameter of the cap 15. But, ideally, the circumference, or perimeter of the stem 25 may be large enough to minimize the number of turns the cord needs to make before the cord is sufficiently drawn up and retained. Dimensions in
When installed, the flange 40 is designed to be biased resistively against the socket wall 70, creating a seam 50. The flange 40 stabilizes the cord retainer spool 10 on the socket by deforming radially away from the center of the cord retainer spool 10 after it has been connected. The flange 40 may be flush against the socket as shown in
The flange 40 of the cap is angled radially inward as it extends from the cap 15. The inward angle of the flange 40 may acts as a guide for the cord 74 to direct it into the seam 50 between the socket 72 and the cord retainer spool 10. The guide is meant to provide a large target area for patients with low dexterity to increase the ease of use.
The excess cord is pulled so the cord enters the seam 50 between the socket and the flange 40 of the cord retainer spool 10. Another benefit of the flange 40 occurs when the cord 74 is fully wound up and inside the spool. The flange 40 acts as a light clasp to hold the end of the cord in place. When the cord is being unwound from the cord retainer spool 10, the flange 40 will flex radially outward providing only a small amount of resistance which allows the cord to be easily unwound when required, but just enough resistance to keep the cord from unwinding any other time.
Three notches 41 provided in the flange 40 around the perimeter of the cord retainer spool 10 act as vents so the part does not create a suction against the side of the socket. The notches 41 may also be used to register the cord 74 to a certain circumferential position, and allow the wearer to easily find the end of the cord to disengage it from the cord retainer spool 10. However, the cord can extend from and be held against the socket by a part of the lip 40 which is not notched.
A small mass 78 can be attached to the tip of the cord 74 to prevent the cord from being engulfed by the cord retainer spool 10. This is a good location for a small piece of plastic or metal with a logo. Another good location for a logo is in the center of the outside face of the cord retainer spool 10 or on the face of the binding barrel's head 62.
As shown in
The present application may be related to application Ser. No. 11/111,483, entitled “Lanyard Suspension System for a Prosthetic Limb”, filed Apr. 21, 2005.