US2899894A - Giani - Google Patents

Description

, Aug. 18, 1959. A. GIANI 2,899,894

FRAME FQR FRAME PRINTING MACHINES Filed Dec. 17, 1957 IN VEN T 01%.

United States Patent FRAME FOR FRAME PRINTING MACHINES Adolfo Giani, Bergaino, Italy, assignor to Reggiani Meccanotex S.A., Bergamo, Italy;

Application December 17, 1957, Serial No. 703,400

Claims priority, application Italy May 21, 1957 3 Claims. (CL 101-123) This invention has reference to an improved frame for frame printing machines and is particularly, but not exclusively, concerned with machines of the kind comprising an endless conveyor which is adapted to feed the cloth or like material to be printed, intermittently and in a succession of steps of equal length, below the frame or from the machine bed 1.

frames of the machine, the machine being operated between each two successive steps so as to print upon the between successive printing operations and to be printed between each two successive steps, it is necessary or desirable that the frame or frames should be lifted out of contact with the material before each step is commenced, and should be lowered into contact with the material at the termination of the step so as to hold the material firmly on the supporting conveyor or machine bed, and the principal object of the present invention is to provide an improved frame printing machine which enables such frame movements to be carried out in a simple and efiicient manner.

A further object of the invention is to provide a frame for frame printing machine which is-of simple and robust construction and which is economical to manufacture.

Still another object of the invention is to enable the, or each, scraper mechanism to commence to move away from the material before the corresponding frame and to continue its return movement after the termination of the return movement of the frame, thereby ensuring that the ink-permeable screen is not damaged by the scraper mechanism during the said movements.

The frame particularly for frame printing machines comprises in combination an L-shaped support, the short arm of which being pivoted to the printing machine bed, the long arm of which serving as a trolley for a scraper mechanism; an inverted U-shaped carrier supporting the printing frame and being pivoted to upper end of said short arm; power operated lifting means for said L- shaped support mounted between the free end of said long arm and said printing machine bed; shock absorber connection means between the free end of said long arm and the bed of the carrier so that a pivotal movement is imparted by lifting means first to the L-shaped support and subsequently to the carrier.

Preferably the frame is mounted in a carrier which is pivoted in the support and is connected to the latter through a lost motion coupling which permits an initial swinging movement of the support relative to the carrier before the said carrier is pivoted to move the frame away from the said material.

In order that the invention may more readily be understood and carried into practice reference will now be made to the accompanying diagrammatic drawing which shows part of a frame printing machine in part-sectional elevation.

!The machine shown in the drawing comprises an L- shaped support 2 of which the one and longer arm serves 2,899,894 Patented Aug. 18, 1959 as a trolley or runway for a scraper mechanism 9 whic may be constructed as described in my co-pending application for Letters Patent Serial No. 703,376, now US. Patent No. 2,863,382, whereas the other and shorter arm of the support is pivoted by its free end about a pin 10 carried in a lug 11 fixed upon and projecting upwardly The scraper mechanism 9 is reciprocable along a guide 32 extending lengthwise of the underside of the longer arm of the support, by motordriven reduction gearing housed within a gear box 31 incorporated in the shorter arm of the said support.

The free end of the longer arm of the support embraces and is fixed to the upper end of a cylinder 8 in which a piston 7 makes a fluid-tight sliding fit and one end of a rod 6 is journalled about a pin 33 extending diametrically of the piston. The said rod projects through and beyond the lower end of the cylinder and its opposite end is pivoted about a pin 34 carried in a lug 11a which, like the lug 11, is fixed upon and projects upwardly of the bed 1.

A pipe 13 opening from the cylinder head, is connected to a source of supply of compressed air or other pressurized fluid and a solenoid-operated or other valve V is installed in the said pipe to control the flow of the air or fluid along the pipe to and from the cylinder, the valve being adapted to be set in either of two alternative positions in one of which it establishes communication between the cylinder and the said source of supply, and in the other of which it puts the cylinder into communication with atmosphere to enable fluid to be exhausted from the said cylinder.

A printing frame 3 is mounted upon and between the free ends of the arms of an inverted U-shaped carrier 30 and one end of the head of the said carrier is pivoted upon a bracket 12 which is fixed upon the side of the gearbox 31 adjacent the cylinder 8. The opposite end of the carrier head is engaged freely by a guide pin 35 which is fixed to and projects upwardly of one flange of an angle shaped bracket 5, the other flange of the said bracket being bolted or otherwise secured to the exterior of the lower end of the cylinder 8.

A coil spring 4 disposed around the pin, is interposed between the bracket and the carrier head 15. The engagement of the pin 35 with carrier head provides a lostmotion coupling between the carrier and the support, and the spring 4 serves as a shock absorber.

In a machine comprising an endless conveyer belt for feeding forwards the cloth or other material to be printed, in a succession of equal steps, one span of the conveyer (not shown) is arranged to run over the bed 1 below the frame 3 and the said material is adapted to be placed upon the said sp'an so that it travels with the belt and is positioned below the frame at the termination of one of the conveyor steps.

T 0 enable such positioning of the material to take place, the valve V is set in the position which establishes communication between the cylinder and source of pressurizcd fluid, with the result that fluid flows into the cylinder; driving the latter upwardly relative to the piston and causing the support 2 to swing upwardly about its pivotal connection to the lug 11. During the initial upward movement of the support, the spring 4 is subjected to, and is compressed gradually by, the combined weight of the printing frame 3 and the carrier. The compression of the spring continues until it is compressed to a degree such that the force exerted by the spring on the carrier is equal and opposite to the force exerted by the combined weight of the carrier and frame on the spring. Thereafter, continued upward movement of the support is transmitted through the angle shaped bracket and the compressed spring, to the carrier with the result that the latter is swung upwardly with the carrier thereby raising the frame out of contact with the conveyor belt and/ or printed material and enabling the belt to be fed forwards through another step to position a fresh piece of material or a different area of the same material, below the frame. The valve V is then set in its alternative position, enabling the fluid previously supplied to the cylinder to be exhausted by the'combined weight of the support, carrier and frame, with the result that the support swings in thereverse direction about the pin and the carrier moves with the said support. As the frame contacts the material to be printed and/ or the conveyor belt, the weight of the support alone continues to exhaust fluid from the cylinder so that the support continues its reverse movement about the pin 10 and the spring is relieved gradually of the combined weight of the carrier and frame and therefore expands to its initial unstressed condition. The initial upwards travel of the support raises the scraper mechanism 9 out of contact with an ink-permeable screen (not shown) which spans the underside of the frame 3 thereby obviating any tendency for the said m echanism to damage the screen as the carrier swings upwardly and downwardly about its pivotal connection to the bracket 12; consequently, it is permissible to use a delicate material such as silk as the printing-frame screen.

When the support returns to its initial position, the

scraper mechanism is brought into contact with the screen by the continued return travel of the support so that, upon being reciprocated by the reduction gearing within the boX 31, the said mechanism is adapted to squeeze printing ink through the screen, and a stencil which is interposed between the screen and the material to be printed, on to the said material.

I claim: I

1. A frame particularly for frame printing machines comprising in combination an L-shaped support, the short arm of which being pivoted to the printing machine bed, the long arm of which serves as a trolley for a scraper mechanism; an inverted U-shaped carrier supporting the printing frame and being pivoted to upper end of said short arm; power operated lifting meansfor said L-shaped support mounted between the free end of said long arm and said printing machine bed; shock absorber connection means between the free end of said long arm and the head of said carrier so that a pivotal movement is imparted by lifting means first to the L-shaped support and subsequently to the carrier.

2. A frame according to claim 1 wherein said power operated lifting means comprise in combination a pneumatic cylinder rigidly connected to the free end of said long arm; means for supplying and exhausting pressurized fluid to and from the cylinder; a piston mounted into said cylinder and a connecting rod pivoted to said piston and said printing machine bed. V

' 3. A frame according to claim 1 wherein said shock absorber connection means comprises in combination a spring interposed between the carrier head and a bracket connected to free end of said long arm so as to be stressed by initial movement of the L-shaped support; guide mean between said carrier head and said bracket.

No references cited.

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