Field of the Invention
The present invention relates generally to a protective helmet and more particularly to a cover plate knock out assembly to facilitate removal of the cover plate from the helmet without the cover plate popping out.
Description of Related Art
The cover plates in the prior art have been mechanically secured with gaskets around front cover plate and in front of a light filter. Examples of the prior art patent documents are as follows:
U.S. Pat. No. 2,354,502 issued Jul. 25, 1944 to W. T. Cockrilf et al. discloses a heat shield for use in arc welding, grinding, painting, etc. having a latch on a lower portion of the hood front for securing an outer shield in closed or operation position on the inner shield. However, this design requires a hinge and a latch for operating the outer shield. Operational components such as a light filter are not moved in the present invention.
U.S. Pat. No. 4,860,389 discloses a protective helmet with a movable transparent screen having a slide associated with a push button which bears on an inner face of the screen for releasing the screen from closure on the helmet a sufficient amount to allow a finger to be placed between the helmet and the screen so as to manually raise the screen and open the aperture of the helmet. However, this design relies on a pivot point via a shaft and spring properties of the slide to return the slide to its resting position. Therefore, additional parts are required.
U.S. Pat. No. 5,084,918 issued Feb. 4, 1992 to Peter M. Breining et al. discloses a safety helmet having a chin guard which locks in a closed position and comprises an opening bar for releasing the chin guard so it may swivel upward by means of hinges. However, this design requires additional parts not needed in the present invention.