Flat Machine Knitting and Fabrics

by H. D. Buck

Control of Automatic Changes

Most of the builders have devised means to do this and one of the best methods is the cylinder or drum idea devised by Dubied & Co., which is shown in Fig. 50. To more easily master the explanation of how this cylinder operates, it should be understood that its only function is to count the rounds and start the main chain at the proper point, the chain stopping itself after having caused the automatic changes necessary at that point.

Fig. 50.
Counting Drum for Short Chain Arrangement, Dubied Machines.

The device consists of a cylinder about 10 to 12 inches long by about 6 inches in diameter, around which are cut two spiral grooves, the larger of which is used to attach stops and the smaller to act as a guide for the fingers i and j, which extend down into and run in the narrow groove and carry the whole block, including the forks k and l, forward or backward on the rods g and h, according to which way the cylinder is turning.

The cylinder is divided in its circumference by the lines into 1,000 divisions, and is turned the distance of one division each round of the machine by means of the roller on the lug o, which raises the lever a, which in its turn raises the pawl c, and its duplicate on the back, which cannot be seen. It can very easily be noted how the pawl c engages the outside ratchet and on being raised it would obviously turn the drum one tooth of the ratchet wheel. The back pawl operates on the center ratchet wheel and inasmuch as this ratchet wheel is cut the opposite way from the outside one, and the pawl is on the opposite side, it is plain that when the back pawl is in operation the cylinder will turn backward.

Both pawls raise each time the lever is raised, but only one at a time can engage the ratchets and the one which engages is governed by the stops A or E on the cylinder. This is done by two guards, one of which may be seen at d, while the other would be between the back pawl and its ratchet, therefore this back pawl could not operate.

These guards are mounted on a triangular or three-cornered frame which is pivoted at the center on the cylinder shaft with the guards mounted on the two lower corners, while the third corner is engaged by the lever n, which in turn is secured to the rod h. Now it is plain that if the bottom or base of this triangle is moved forward or toward the machine, the front guard would move under and disengage the front pawl while the back guard would move down and free the back pawl and allow it to operate on its ratchet wheel.

Keeping this triangular arrangement in mind we will turn our attention to the block, of which the fingers i and j, and the forks k and l, form a part. As noted before there are three fingers extending down to the cylinder from the block, two of which (i and j) reach down to but do not touch the cylinder, while the third one, which is between these two, engages in the smaller of the two grooves.

The block is constructed so it must move lengthwise of the rod as one piece, but each part is free to move laterally independent of another. The block is not fixed in any manner to the top rod and the only positive connection it has with the lower rod h is with a key in the center finger which engages in a keyway which is cut the full length of the rod. It should now be clear to the reader that so long as there is no obstruction placed in the path of the center finger it will simply follow the small groove and gradually move over toward the right (if the front pawl is operating and the top of the cylinder is turning away from you) until it comes to the Stop, E, which it will be noted lies across its path.

On account of the key in this center finger engaging the keyway in the rod h, it naturally follows that when the finger comes up to the stop E, the next movement of the cylinder will swing it away from you and this turn of the rod h, will swing the lever n, and through this will swing the triangle on which the guards d, are mounted, bringing the front guard d up under the front pawl and at the same time will free the back pawl on the center ratchet, thereby reversing the movement of the cylinder.

Upon the return of the block to its starting point at the left end of the cylinder, its direction of movement is again reversed in the same way by the stop A. Stop A is set at division O and is never moved, but stop E may be placed at any number of the divisions corresponding to the number of rounds in the garment. This point will be taken up again further along.

Now to give our attention to the side fingers i and j. These are constructed so that the left one, or i, will swing freely toward you but an attempt to swing it away from you will engage the fork k, which by contact would swing the rod g, which through the connection f would raise the lever e, and this by a pull on the cord m would start the main chain in motion. The right finger j works in precisely the same manner, only that it swings freely when moved away from you and starts the main chain in motion when moved toward you, by contact of the fork l with rod g.

With the foregoing in mind it should hardly be necessary to explain that the stops C and D are for the purpose of putting the main chain in motion by coming in contact with the fingers i or j; C to operate when the cylinder is turning the top away from you by tripping finger i, and D when it turns toward you by tripping finger j. It will be noted that the stops A and E have short extensions which extend forward along the side of the small groove. These cause the side fingers, i or j, to start the main chain at the same time that the direction of the movement of the cylinder changes. If for any reason this is not desired, a stop like B may be used instead of these, and then the cylinder will reverse without starting the main chain.

Going back to the setting of stop E, where the garment to be made has less than 1,000 rounds, it is customary to set this stop as well as the intermediate stops, like C and D, to make a complete garment on its forward movement and a second one on its return. But if the garment should have more than 1,000 rounds, let us say 1,500, then stop E would be set on division 750 and the small stops like C, which are for tripping the finger i, would be placed at the proper place to start the main chain for the automatic changes in the first half of the garment. The stops like D, which are for tripping the finger j, would do the same for the last half of the garment.

If there is no change to be made in the middle of the garment the knitter may avoid it by either one of two means; either by using a stop like B, which will reverse the movement of the cylinder without starting the main chain, or by using a stop like E, which starts the main chain at the same time it reverses the movement of the cylinder, but in this event he must put in the main chain two extra links with a stud attached for stopping the chain immediately after starting without acting upon any of its automatic mechanism.

If the fabric being made does not require the use of the cylinder all that it is necessary to do to stop it is to raise up the lever a, and draw the roller b out against the head of its stud.