Abstract: A vacuum relief valve is provided. The vacuum relief valve includes a body having a side wall, and a stem that is movable with respect to the body between an open position and a closed position. The stem is biased in the closed position. The vacuum relief valve further includes a first sight glass coupled to the body and configured to enable visual inspection of a sealing area of the vacuum relief valve. The sealing area includes at least a portion of said stem.

Abstract: A vacuum relief valve is provided. The vacuum relief valve includes a body having a side wall, and a stem that is movable with respect to the body between an open position and a closed position. The stem is biased in the closed position. The vacuum relief valve further includes a first sight glass coupled to the body and configured to enable visual inspection of a sealing area of the vacuum relief valve. The sealing area includes at least a portion of said stem.

Abstract: The contrast between a target and the target markers or line divisions on a graticule disk of a sight, especially for a hand-held weapon, is enhanced by a device which illuminates the graticule disk with refected liight. The device has an attachment member which is rapidly mountable to and removable from the sight housing. The attachment member carries a frame which holds glass bodies filled with gaseous tritium and coated on the reflecting surfaces with a luminous lacquer or paint. The light entry and exit sides are not coated. The attachment member holding the frame permits shifting the frame between a first effective position in which light collected by the tritium filled glass bodies is transmitted onto the graticule disk, and a second ineffective position in which light is not transmitted to the graticule disk.

Abstract: A support device for a field winding of a field spider includes first and second support members which bear at least partially against free coil surfaces of adjacent field coils. The first and second support members mutually support one another against the field coils with various devices provided to urge the first and second support members apart. The support members may either be angled or flat with the flat support members crossing one another.