Cam-wedge locking mechanism

#The present invention relates to a locking mechanism. In particular, the present invention relates to a cam and wedge locking mechanism to selectively position a surgical retractor blade attached to a retractor mounting apparatus.

#During many types of surgical procedures it is necessary to use a retractor to hold back tissue proximate a surgical incision. The retractor enables a surgeon to work at and in the surgical incision. Retractors typically include a blade and an arm, such as a shaft, to which the blade is attached. The retractor is generally held in place by attachment to a retractor support apparatus that is positioned over a support surface, such as an operating table. The retractor support apparatus is usually attached to a side rail located along one or more sides of the operating table by a clamping device, such as a fulcrum clamp or a cammed clamp.

#Current retractors are not easy to manipulate and position over the surgical incision because the arm is typically a solid inflexible rod. Clamping mechanisms to lock the retractors in a precise location are typically cumbersome and require complex maneuvering that may increase the risk of injury to the patient. Typically, adjustment of the retractor occurs at the clamping device which attaches the retractor to the sides of the operating table. Positioning the retractor at this location remains challenging since the clamping device may be difficult to operate, or be located at a place that may increase the risk of contamination to the patient.

#FIG. 1 is a perspective view of a first embodiment of the present invention with a retractor blade in a first position (detailed) and a second position (broken lines).

#FIG. 2 is a cross-sectional view of the first embodiment of the present invention with the retractor blade in a first position (detailed) and a second position (broken lines).

#FIG. 3 is a perspective view of a second embodiment of the present invention with a retractor blade in a first position (detailed) and a second position (broken lines) along with a lever of a releasing mechanism in a non-engaging position (broken lines) and an engaging position (detailed).

#A retractor apparatus of the present invention is generally indicated at 10 in FIG. 1. A locking mechanism of the present invention is generally indicated at 12. The locking mechanism 12 is designed to automatically permit rotational movement of a retractor blade 50 in one direction only, from a first upright position 16 to a second downward position 18 (shown in broken lines), while the locking mechanism 12 is engaged. The locking mechanism 12 includes a cammed member 14, a wedge member 20, and a spring 22, all enclosed within a housing 24 as illustrated in FIG. 2.

#The cammed member 14 includes a through-bore 26, the through-bore 26 defining an axis of rotation 27 for the cammed member 14. The housing 24 includes first and second mating apertures 28, only one of which is illustrated. The mating apertures 28 are aligned with each other by being positioned on opposing wall sections. The cammed member 14 is positioned within the housing 24 such that the through-bore 26 aligns with each mating aperture 28.

#A securing pin 30 is inserted through the mating apertures 28 and the through-bore 26 of the cammed member 14, thereby rotatably securing the cammed member 14 to the housing 24. Once secured within the housing 24, the cammed member 14 is freely rotatable between the first upright position 16 and the second downward position 18.