75 MM. GUN CARRIAGE
MODEL OF 1897 MI(FRENCH)
PLAN VIEW
The principal parts of the carriage are: trail, axle, wheels, brakes, shields, angle of site elevating mechanism, range elevating mechanism, traversing mechanism, rocker, cradle and sights.
When traveling or resting, the tube rests on the cradle which supports it by means of the jacket. When firing, it recoils on the cradle by means of the rollers. The jacket has two pairs of rollers, and the muzzle hoop is provided with a single pair of rollers. On the upper part of the cradle are the lower slides, on which the jacket rollers, supporting the tube, roll during the recoil. When the jacket rollers are about to leave the lower slides, the muzzle rollers come under the upper slides; the tube is then supported until the end of the recoil by the muzzle rollers and the more forward of the two pairs of jacket rollers. This device gives the gun a long recoil upon short slides. Inclined planes are used in such a manner that when the gun returns into battery the rollers rise from the lower slides thereby relieving the slides from the weight of the tube when the tube is in the traveling position.
The carriage supports the cradle which in turn supports the tube. The cradle and the tube together are displaced, during the laying for elevation with respect to the carriage which remains stationary. The carriage is held steady on the ground by means of the trail spade which with abatage prevents the carriage from recoiling on the ground.
Abatage consists of elevating the wheels on the brake shoes which are provided with small spades which prevent lateral movement. The brake shoes are fastened to brake beams attached to a sliding rack beneath the trail in such a manner that the abatage frame may be placed under the carriage during travel. In preparing to fire, the frame may be adjusted to allow the brake shoes to slip from a position in rear of the carriage wheels to a point directly beneath the wheels.
75-MM. GUN CARRIAGE, MODEL OF 1897, MI(FRENCH) WHEEL BRAKE MECHANISM
Abatage is accomplished as follows: (1) The brake shoes are dropped to the ground in rear of the point of contact of the wheels with the ground; (2) The trail is lifted, turning around the axle, until the spade is about five feet in the air. Tie rods and a slide working on a rack beneath the trail move forward in this action; (3) The trail is then brought down. The rack prevents the slide from moving to the rear and the carriage turns on the abatage frame until the wheels rest upon the brake shoes. This gives the gun a three point support, two small spades under the wheels and a larger one at the end of the trail.
Laying in direction is accomplished by traversing the piece on the axle. The trail spade is fixed and the axle is straight and rigid so that in the movement of the gun to the right and left on the axle both wheels must turn—one to the front and one to the rear. The device for laying for direction is composed of a threaded axle, which is prevented from rotating by a spur and a sliding nut which is contained in a box fixed on the left flask of the gun. This nut bears one of the bevel gears, which is put in motion by the hand wheel. The traverse is three degrees either side of the center or a total of 6 degrees or about 105 mils.