Patent GB-776051-A (GB)
Title: Improvements in pneumatically operated pressing machines
Inventor: WALKER THOMAS BRADLEY
IPC: D06F71/06
Filed: 1951-03-15
Abstract: 776,051. Ironing presses. BRAITHWAITE & SON, ENGINEERS, Ltd., I. March 17, 1952 [March 15, 1951], No. 6237/51. Class 138 (2). In a garment press, air under pressure is supplied to a pneumatic cylinder to open or close the head E<SP>2</SP> by a valve or valves manually operated by a lever and moved in either direction from a neutral position, the movement of the head resulting from manual operation of the lever causing the valve or valves to return to a neutral position, the distance the head moves before the or each valve again assumes a neutral position depending on the distance the lever has been displaced, so that for every position of the lever there is a corresponding position of the head in which the valve is in its neutral position, and any movement of the lever is immediately copied by the head. The head E<SP>2</SP> is carried by a lever E pivoted at E<SP>1</SP> on a frame Q, the pneumatic cylinder (not shown) being connected to the counterweighted end of the lever E. In one example (Fig. 1) a lever A is pivoted at a<SP>1</SP> to the lever E, and at a2 to the substantially mid-point of a link B. Link B is pivotally connected at b<SP>1</SP> to a link C which is pivoted to the frame Q at c<SP>1</SP>. The end b<SP>2</SP> of link B is connected to a rod D which slides in a bridge e<SP>1</SP> on the lever E and carries stops d<SP>1</SP>, d2. A spring G attached to the bridge e<SP>1</SP> and to the lever A normally holds stop d<SP>2</SP> against the bridge e<SP>1</SP>. The end a<SP>2</SP> of the lever A is connected to a valve or valves in a casing k<SP>9</SP> or T, controlling the supply of air to the operating cylinder of the machine. On moving rod D by means of a manually controlled lever carried by the head lever E, the lever A is moved anti-clockwise from normal position, thereby admitting air to the cylinder to move the head E<SP>2</SP> towards the closed position. The resulting displacement of link C returns the lever A to its normal position and brings the head to rest in a position depending on the distance the operator has moved the rod D. In a modification (Fig. 2, not shown) the link C is replaced by a cam of suitable contour secured to the frame Q of the machine, and a roller rotatably mounted on the end b<SP>1</SP> of the lever B is held in contact with the cam by the spring G. In a further modification (Fig. 3, not shown) the displacement of the lever A is obtained by displacing the cam by control means mounted on the stationary part of the machine, and the cam-following roller is mounted on an extension of the lever A. The valve controlling the supply of air to the press operating cylinder may be of the slide type but is preferably of the type having an oscillatory rotating motion (Figs. 4, 5, not shown) and in this case is coincident with the fulcrum a<SP>1</SP> of lever A. The press may be arranged for two handed control by duplicating the control rod D (Fig. 6, not shown) and connecting the end b<SP>2</SP> of the link B to the mid point of a link pivotally connecting the two control rods. The stops d<SP>1</SP> are so arranged on the rods D that if only one control rod is operated the press head moves to a position adjacent to the buck but without exerting pressure thereon. In Fig. 7 the motion of the head is compensated by combining the methods of Fig. 1 and Fig. 3 (not shown), viz. by means of the link C and by a cam F and roller J. The cam F is pivoted to the frame Q at f and its position is controlled by means of a rod H attached to a foot pedal (Fig. 10, not shown). The shape of the cam F is such that the head E<SP>2</SP> is brought adjacent to the buck S without exerting pressure thereon. Final pressure can only be obtained by the operator using two hands to operate each of two control handles. The head E<SP>2</SP> can be locked in contact with the buck S by the engagement of a pin a<SP>3</SP> on an extension of the lever A with a pivotally mounted latch L. The latch L is held in contact with the pin a3 by a counterweight L2 and can be disengaged by a rocking lever P connected to a second foot pedal (not shown).