US2011645A

US2011645A - Machine for perforating sheet material

Info

Publication number: US2011645A
Application number: US710120A
Authority: US
Inventors: Walter T Miller
Original assignee: Individual
Current assignee: Individual
Priority date: 1934-02-07
Filing date: 1934-02-07
Publication date: 1935-08-20
Anticipated expiration: 1952-08-20

Description

Aug. 20, 1935. w. T. MILLER MACHINE FOR PERFORATING SHEET MATERIAL Filed Feb. 7, 1934 \M an ex /1,. 'IIIIIIIIII 11 1'! I 2 TH ,dzlllllllu iififmli 7 71 I II/IIIIIIIIIIIIIIII Patented Aug. 20, 1935 2,011,645 MACHINE ron rnarona'rmo snnn'r MATERIAL Walter T. Miller, Gloucester, Mass. Application February 1, 1934, sci-n1 No. 710,120

8 Claims.

My invention relates to machines for perforating sheet material by means of electric sparks.

In the processing of certain imperforate sheet material, it is found advisable to perforate the material with minute holes to facilitate evaporation, and to prevent sweating, and the object of my invention is to provide means by which this may he done by producing successive lines of perforations across the sheet material, by means of electric sparks across a spark gap through which the sheet material is moved.

My invention consists in the novel construction of a machine and the method of operation to accomplish my object. In the accompanying specifications and claims and the drawing forming a part thereof, I have described and illustrated a preferred embodiment of my invention together with two modified forms that maybe used, but do not confine myself to these embodiments as other modifications may be made within the scope of the appended claims.

In the drawing,

Fig. 1 is a sectional elevation of a machine for the purpose specified in which my invention is embodied.

Fig. 2 is a plan of the same.

Fig. 3 is an enlarged fragment showing one means for conveying the electric current to terminals.

Fig. 4 is a modification in which one terminal is reciprocated in operative relation to a fixed terminal of extended form.

Fig. 5 is a modification in which a pair of terminals are reciprocated across the path of movement of the sheet material.

Referring to the drawing,

The reference characters refer to like parts on all figures and in the modifications, Figs. 4 and 5, the indices, anda refer to elements similar in function to the main characters.

I! is a machine frame on which is rigidly mounted the goose-neck H. In this goose-neck is journalled the hollow shaft l2, to one end of which is secured the disc i3, and to the other the driving pulley I", driven from a source of power not shown, by the belt It, or by an equivalent. to rotate the disc at a relatively high speed. Insulated in the disc I! are spark points l4, l4 and II" equidistant from the axis of rotation and preferably spaced equi-angular. The disc may be of insulating material, or of conducting material with the spark points insulated therefrom. The spark points are electrically connected by suitable, insulated means to the main conductor i6, andonemeansisshowninFig. 1 andin theenlarged plan, Fig. 3. Referring particularly to Fig. 3, the conductor It extends through and is insulated from the shaft l2, and terminates in a hub l1. Brushes l8 insulated from the disc it, are mounted within the hub i9 thereof, and from 5 The two conductors l6 and 20, the latter being formed as an extended terminal, are connected by respective wires 2|, 22, to an induction coil 23 in circuit by means of

mains

24, 25, with a source 90 of electric power not shown. Potential is built up by the induction coil, and as the disc is rotated, a succession of electric sparks occurs as and while each spark terminal opposed terminal, which is formed concentric with the path of movement of the movable ter- The sheet material A is drawn over the 20 and between it and the path of rodrawn from a reel 3|. As the machine is operated, a series of sparks from each movable terminal perforates the moving sheet and forms successive arcs of minute perforations laterally of the sheet, the relative speed of rotation of the movable terminals and the movement of the sheet ma- 40 be in the form of arcs laterally across the sheet, but straight lines of perforations may be made as shown in modification shown in Fig. 4. In this case, I mount one terminal W in a crosshead If suitably mounted in a sliding bearing i2, and adapted to be reciprocated by means of the crank 32 and pitman 33, over a fixed terminal 20, the shaft 34 being mounted in the gooseneck I I. The sheet A may be moved in the manner above explained, in which case the lines of perforations would be at an angle with the selvage of the sheet, but if the sheet is moved intermittently, the lines may be arranged normal to the selvage, in either case separated according to the movement of the sheet.

In Fig. 5, I mount the terminal 20a in the crosshead Ito, and the two terminals W and Ila are reciprocated in unison, by means slmilarto those described as applying to Fig. 4, the elements being similar and identified by the index a.

Having thus described my invention, I claim:

1. In a machine for perforating sheet material by means of electric sparks, a terminal element, movable laterally in a fixed path and in parallel relation to a sheet of material, and in such relation to a blade like terminal extended laterally, that a spark gap of unvaried width is formed therebetween when the terminals are opposed.

2. In a machine for perforating sheet material by means of electric sparks, the combination of a terminal element movable laterally and in a fixed path in such relation to a blade like terminal, that a spark gap of substantially unvaried width is formed between the former and the edge of the latter when the terminals are in opposition.

3. In a machine for perforating sheet material by means of electric sparks, the combination of a terminal element movable laterally in a fixed path in such relation to a fixed terminal that a spark gap of substantially unvaried width is formed therebetween when the terminals are in opposition, one terminal being a blade like extension in the direction of movement of the movable terminal.

4. A machine for perforating sheet material by means of electric sparks, including a pair of terminal elements, one fixed, the other relatively movable laterally in a fixed path, and one terminal being a blade like extension and in such relation to the other, that a spark gap of substantially unvaried width is formed between the former and the edge of the latter, while the movable terminal is opposed to the other.

5. In a machine for perforating sheet material by means of electric sparks, the combination of a blade like fixed terminal extended in a lateral plane, and a terminal movable in a fixed path in a plane parallel thereto and in such relation that a spark gap of substantially unvaried width is presented while the movable terminal is moved laterally in opposition to the fixed terminal.

6. In a machine for perforating sheet material by means of electric sparks, the combination of a terminal rotatable about a fixed axis, and a fixed terminal in the same radial relation to the said axis, and separated from the plane of rotation of the movable terminal to form a spark gap of unvaried width when the terminals are opposed.

7. In a machine for perforating sheet material by means of electric sparks, the combination of a terminal rotatable about a fixed axis and a terminal extending concentrically with said axis and in a plane parallel with and separated from the plane of rotation of the movable terminal by a spark gap of substantially unvaried width while the terminals are opposed.

8. A machine for perforating sheet material by means of electric sparks, including a plurality of terminals movable in a path concentric with a fixed axis; a fixed terminal concentric with said axis and at the same radial distance therefrom, the plane of rotation of the rotating terminals being parallel to the fixed terminal and separated therefrom to provide a substantially unvaried width of spark gap while each movable terminal is opposed to the fixed terminal; means for supplying electric current of sufiicient potential to provide a succession of sparks between the rotated terminals and the fixed terminals while they are opposed.

WALTER T. MILLER.