Abstract: A torsion-detecting pneumatic impact tool is provided. A hammering set having at least one hammering block and a rotating portion which is connected with each hammering block. A transmission shaft penetrates through each the hammering block. A torsion detecting unit includes a marking piece which has a plurality of blocks, at least two sensors which detect the marking piece and an processing unit which is electrically connected with each the sensor. The hammering set, the marking piece, and the rotating assembly rotating synchronously. When each the hammering block swing strikes the transmission shaft in a direction, the hammering set and the marking piece rotate reversely slightly because of the counterforce of swing strike. When the marking piece rotates reversely, the processing unit receives a signal of a degree of rotation of the blocks detected by the at least two sensors and computes a torsion value.

Abstract: A torsion-detecting pneumatic impact tool is provided. A hammering set having at least one hammering block and a rotating portion which is connected with each hammering block. A transmission shaft penetrates through each the hammering block. A torsion detecting unit includes a marking piece which has a plurality of blocks, at least two sensors which detect the marking piece and an processing unit which is electrically connected with each the sensor. The hammering set, the marking piece, and the rotating assembly rotating synchronously. When each the hammering block swing strikes the transmission shaft in a direction, the hammering set and the marking piece rotate reversely slightly because of the counterforce of swing strike. When the marking piece rotates reversely, the processing unit receives a signal of a degree of rotation of the blocks detected by the at least two sensors and computes a torsion value.

Abstract: A pneumatic motor includes a cylinder, a rotor and a drive shaft. The cylinder includes a cylinder body having two ends, a first cover and a second cover. The first cover is mounted on one of the ends of the cylinder body and has a first bearing housing, a first bearing and a first blocking ring. The first bearing is mounted in the first bearing housing and has an annular clearance. The first blocking ring is mounted between the first bearing housing and the first bearing and covers the annular clearance of the first bearing. The rotor is mounted rotatably in the cylinder body. The drive shaft is mounted securely through the rotor. When compressed air is expelled from the cylinder body, the compressed air does not blow lubricants out of the first bearing because the first blocking ring closes the annular clearance.

Abstract: A pneumatic sanding machine includes a body, a pneumatic motor assembly mounted in the body and a control valve detachably mounted in the body to change the path of compressed air that actuates the sanding machine. The control valve includes a first portion selectively closing one of different air passages in the body at a time, a second portion and a neck portion interconnecting the first portion with the second portion. Thus, a dust bag or a vacuum cleaner can be connected to the sanding machine to collect dust or sanding debris so that the sanding machine provides three different ways of dust collection, one of which is not to deal with the powder, the second is to collect the powder into a dust bag, and the third is to vacuum the powder into a vacuum cleaner.

Abstract: A pneumatic sanding machine includes a body, a pneumatic motor assembly mounted in the body and a control valve detachably mounted in the body to change the path of compressed air that actuates the sanding machine. The control valve includes a first portion selectively closing one of different air passages in the body at a time, a second portion and a neck portion interconnecting the first portion with the second portion. Thus, a dust bag or a vacuum cleaner can be connected to the sanding machine to collect dust or sanding debris so that the sanding machine provides three different ways of dust collection, one of which is not to deal with the powder, the second is to collect the powder into a dust bag, and the third is to vacuum the powder into a vacuum cleaner.