Abstract: An improved structure of a sand blast gun includes a body, a guide tube accommodated in the body in a longitudinal direction, and a stop valve disposed in a radial direction. The stop valve has two guide posts. A shaft having a sleeve fitted on the outside straddles over upper portions of the guide posts. The guide posts are respectively fitted with pressure springs and inserted into holes of the body. An urging top end is firstly fixed on a center of a securing plate that is screwably mounted at the bottom side of the guide posts such that the urging top end extends into a radial round hole of the body to urge against a catgut tube to close the passage. When a trigger of the sand blast gun is pulled, it pushes the shaft and the guide posts to cause the pressure spring to retract to thereby cause the securing plate on the bottom of the guide posts and the urging top end to displace outwardly.

Abstract: A rod rest including a holder frame, a main support having a barrel at the bottom pivoted to the holder frame at one end; two anchoring bars pivoted to the holder frame at an opposite end; an auxiliary support pivotably fastened to the main support by a wing screw; a locating shaft turned in the barrel of the main support and connected between the holder frame and a circular coupling plate; brake means mounted in an axial cut in the locating shaft, and a lever adapted for releasing the brake means; wherein when the main support is turned outwards relative to the anchoring bars, it is released from the constraint of the brake means and allowed to be turned outwards further; when the main support is turned inwards toward the anchoring bars, the brake means is forced into braking position to stop the main support from turning.