DESCRIPTION AND FUNCTIONING
5. DESCRIPTION (figs. 1, 2, 11, 12, 13, and 14).
a. The launcher is essentially a long open barrel with a stock which houses the electrical firing mechanism. The tube is approximately 54 inches long and has a smooth bore.
b. The launcher has a front and rear sight, both of which are fixed to the barrel on the left side. The rear sight is of the peep type. The front sight consists of three studs which are used for ranges of 100, 200, and 300 yards. Intermediate or greater ranges, lead, and windage must be estimated by the firer.
c. Ahead of the front sight is assembled a flash deflector (fig. 3). The deflector is a conical wire screen with a mounting clamp. It is secured to the tube by the deflector screw and nut. When properly assembled, the mounting clamp of the deflector overlaps the muzzle end of the launcher. The function of the deflector is to deflect occasional particles of unburned powder which might impinge upon the firer's face.
d. The hand grip consists of the left and right trigger grips attached to the trigger support. The trigger support accommodates the trigger guard, trigger, and the lower and upper trigger switch contacts. The trigger is pinned at its upper end to the trigger support and is free to pivot. When the trigger is squeezed, it presses the bar contact against the lower trigger switch contact to complete the electric circuit. When the pressure on the trigger is released, the trigger spring forces the trigger to the forward position so as to break the electric circuit.
e. The stock has a narrow vertical slot by means of which it slips over the stock support to which it is attached by screws. In the bottom of the stock there are two vertical cylindrical compartments for accommodating four batteries. The two batteries in the rear compartment are in actual use; the two batteries in the front compartment are spares. On the left side of the stock is a small electric lamp for testing the electric circuit and battery. The lamp is connected in parallel with the firing mechanism and it lights when the trigger is squeezed, regardless of whether a rocket is in the launcher or not. A spare lamp is carried in a circular compartment on the right side of the stock under the circuit indicator cover. The bottom of the stock is fitted with a hasp assembly which keeps the batteries in position and completes the electric circuit. The hasp assembly is kept closed by a spring actuated hasp catch which engages the stock pin. The battery spring contacts the batteries and is connected by wire to the stock support to complete the electric circuit.
f. The face guard is on the barrel above the stock. The guard serves to protect the firer's face from the heat in the tube. The guard is pressed on to the barrel and is held in position by its tension.
g. The portion of the barrel from the rear of the stock to the insulated contact spring is wound with bracing wire. The contact springs serve as connecting points for the contact wire leading from the rocket. In this manner, the circuit is completed. At the rear of the barrel is a spring actuated tail latch assembly. The function of the latch is to engage notches on the tail of the rocket and hold it in position for firing. The breech guard at the breech end of the barrel facilitates loading of the rocket, protects the tail latch assembly, prevents distortion of the end of the barrel, and prevents entry of dirt and foreign material when the end of launcher rests on the ground.
h. When the 2.36-inch AT Rocket Launcher M1A1 is issued, it is equipped with a battery designated as the Eveready 791-A, to provide current for operating the firing mechanism. This battery consists of two dry cell batteries of the Eveready No. BA-42 type, size C, which are jointed together and placed in a cardboard container. When replacement is necessary and a battery of the original type cannot be supplied by ordnance personnel, two separate cells of the battery BA-42 type will be used. These cells are a standard Signal Corps item which are readily available in the field. Each is 15/16 inch in diameter and 1 15/16 inches in over-all length.
a. When the trigger is squeezed, it forces the bar contact against the lower trigger switch contact to complete the circuit.
b. The passage of the electric current through the rocket sets off an electric igniter in the rocket which in turn ignites the propelling charge. Rearward escape of the powder gases through a jet forces the rocket out of the barrel with a muzzle velocity of about 265 feet per second. Propulsion of the rocket is by jet action of the propellent powder and hence there is no recoil.