US2166907A

US2166907A - Ink pad for duplicating machines

Info

Publication number: US2166907A
Application number: US236434A
Authority: US
Inventors: William F Herterich
Original assignee: TECHNYGRAPH
Current assignee: TECHNYGRAPH
Priority date: 1938-10-22
Filing date: 1938-10-22
Publication date: 1939-07-18
Anticipated expiration: 1956-07-18

Description

INVENTOR M LLI/1M EHT'H TTORNEY W1 F. HERTERICH INK PAD FOR DUPLICATING MACHINES Filed OCb. 22, 1938 July 18, 1939.

Patented July 18, 1939 UNITED STATES PATENT OFFICE William F. Herterich, Brooklyn, N. Y., assignor to The Technygraph, Techny, Ill.

Application Gctober 22, 1938, Serial No. 236,434

7 Claims.

This invention relates to improvements in rotary stencil duplicating machines and more particularly to an improved ink pad and the manner of its attachment to the duplicating machine.

The primary object of the present invention isto provide an improved ink pad for rotary stencil duplicating machines and to improve the method of attaching the pad onto the machine.

A further object of the invention is to provide an improved ink pad which is readily attachable and removable from the drum of the duplicating machine.

In accordance with the objects of the present invention, the improved ink pad comprises a sheet of suitable fabric such as cotton flannel of the desired size which is provided at one end with a springy yielding attachment member and at the other end with an attachment means adapted to apply the desired amount of stress or strain to the pad as it is finally secured to the cylinder or drum of the duplicating machine. The improvements of the present invention particularly relate to machines of the type described in Brasseur Patent No. 1,607,386.

Other features and objects of the present invention will be apparent to those skilled in the art from the following more detailed description thereof taken in connection with the accompanying drawing in which:

Fig. 1 is an enlarged broken sectional View of a portion of the cylinder or drum of a stencil duplicating machine such as that shown in the abovementioned patent or those now commonly in use,

i showing the arrangement for attaching one end of the ink pad to the rotary drum.

Fig. 2 is a view similar to that of Fig. 1 showing the manner of attaching the other end of the ink pad to the rotary drum.

Fig. 3 is a broken front View (looking up in Fig. 1) showing the manner of attaching one end of the pad to the cylinder as in Fig. 1.

Fig. 4 is a View similar to Fig. 3 (looking up in Fig. 2) showing the opposite end of the pad attached to the drum as in Fig. 2.

Fig. 5 is a broken perspective View of the improved ink pad of the present invention.

Fig. 6 is an enlarged View of one of the pivoting or leverage arms comprising a part of one end of the improved ink pad.

Rotary stencil duplicating machines now in use and shown in the above-mentioned patent oomprise a cylinder or drum having end walls connected by a perforated diaphragm forming a substantial portion of the outer periphery of the drum. The remaining portion of the periphery of the drum is usually on a considerably smaller diameter so that space is provided within the arc of the outer periphery for attaching the ink pad and stencil sheet over the diaphragm and for other attachments and structure.

In Figs. 1 and 3 is shown a broken section of the drum at the leading end of the perforated diaphragm; one end plate of the drum being shown at 2 and the diaphragm at 4. The diaphragm 4 is attached to a cross plate 6 provided with spaced prongs 8 which are adapted to engage the attachment members of the leading end of the ink pad designated as I0, which is shown mounted on the diaphragm 4. This end attachment member of the pad comprises a heavy spring-steel rod or wire l2 of about 9 gauge over which the fabric of the pad is secured, as shown in Figs. 1 and 3. The ends of the Wire member l2 are bent back as shown in Fig. 3 and made into flattened engagement members adapted to engage the prongs 8. Each of these engagement members comprises a positioning point or thumb I4 adapted to engage the side of the prongs 8, and an arced hook member I6 adapted to pass around the back of the prong 8 to hold the pad on the drum.

In attaching the leading end of the pad to the drum therefore, it will be apparent that the only steps necessary are to place one of the points I4 against the corresponding prong 8, which will automatically position the opposite end and then merely pull the pad forward until the hooks I6 engage the prongs 8.

The trailing end of the ink pad is constructed and applied to the cylinder in the manner shown in Figs. 2 and 4 in which the fabric of the pad I0 is shown stretched over the diaphragm 4, and the latter being supported on an inwardly extending plate i8 attached to thek edge of the diaphragm and the end plate 2. This portion of the drum or cylinder is provided with a rod 2li which extends across the cylinder near the trailing end of the diaphragm. The ends of the rod extend through slots in blocks or casings 22. The ends of the rod 20 are attached to suitable mechanism 24 for moving the rod 20 toward or away from the center of the drum. This mechanism is now in use on commercial machines and comprises no part of the present invention except in general combination with attachment of the trailing end structure of the improved ink pad.

The trailing end structure of the ink pad comprises a spring-steel wire or rod 26 of approximately 9 gauge bent in the U-shape shown in Figs. 4 and 5. The fabric of the pad is passed over the rod 26 and secured thereto in a manner similar to that of the opposite end of the pad. Each of the ends of the wire 26 are bent back at right angles to provide extensions about an inch in length, flattened at their ends, and punched to form a two-prong fork as shown in Figs. 2 and 6. This fork comprises opposite prongs 28 cut so as to form an approximate semicircle adapted to t over the rod 20.

The trailing end of the ink pad is attached to the machine (after the leading end) by first setting the prongs 28 of the wire 26 over the rod 20 as shown in Fig. 4 and swinging the end of the pad into the position shown in Fig. 2, so that the fabric of the pad is stretched over the edge of the diaphragm 4 and over the rod 20. The trailing end of the pad is provided with openings 30 which expose the wire 26 at these points. As the trailing end of the rod is forced into place, it is held there by pivoted hooks 32 which engage the end of the pad over the wire 26 at the point of the openings 3D. With the use of certain types of hooks, the openings 36 are entirely unnecessary,

because the hooks will retain the trailing end of the pad in position because of the thickness and rounded character of the rod 26 in the end of the ink pad. The hooks 32 are pivoted as shown and preferably provided with springs not shown), to

, keep them in position over the end of the pad.

The U-shape of the wire 26 and the fact that its ends point toward the opposite end of the pad ill provide a toggle or leverage action for stretching the ink pad into position. As the ink pad is stretched into position any unevenness in stretching or other irregularity in the fabric will be taken care of by the resilience of the spring ends of the wire l2. These ends act independently of each other and materially aid in adjusting the fabric to the perforated diaphragm. Any material variation in the length of the pads used on a given machine may be readily taken care of by varying the position of the rod 2B with respect to the edge of the diaphragm 4, by use of the mechanism 24 on either or both ends of the rod.

The fabric of the pad is preferably attached to the wires l2 and 26, as shown in enlarged detail of Fig. 6 by lapping the fabric over the long straight portions of each wire and lapping the 1 end section 34 of the fabric back along the main section of the fabric. This end section is preferably vulcanized to the main section of the fabric by inserting a strip of rubber between the two sections adjacent to the wire and pressing the tWo sections of the fabric together while heating the same. This forms a very strong stiff bond. The ends are preferably finished by lacquering all of lthe lapped portion of the fabric 34 as well as that on the opposite side and that over the Wires. On

2;, the trailing end of the pad the fabric is preferably lacquered for a distance sufficient that the portion of the pad on the end of the diaphragm is lacquered for at least one half inch (see Fig. 6). This prevents seepage of ink through the pad into the space beyond the diaphragm. Instead of using lacquer the fabric at this point may be impregnated with an ink-resisting plastic such as a wax, to seal the end of the diaphragm. Any lacquer or plastic which will prevent the oils contained in inks from attacking the vulcanized rubber are suitable for coating the ends of the pad; for example a varnish or a cellulose lacquer. A plastic may protect the rubber and seal the trailing end of the diaphragm. The wires I2 and 26 are preferably sealed (vulcanized) to the fabric in the positions shown, so that the ends of the wire I2 extend beyond the pad proper, while the ends of the wire 26 extend back along the edges of the fabric.

Various modifications may be made in the improved ink pad and its manner of attachment without departing from the spirit and scope of the invention, and such changes are contemplated in accordance with the scope of the appended claims.

Having thus described the invention in its preferred form what is claimed as new is:

l. In a rotary stencil duplicating machine, in combination a cylinder having a perforated diaphragm, an ink pad extending over said perforated diaphragm and attached to said cylinder by end attachment members, one of said end attachment members comprising a heavy wire to which the fabric of the ink pad is secured, the ends of said wire extending beyond the end of the pad and being bent inwardly toward the opposite sides at an acute angle, a positioning point on the end of each wire end, and a hook also on each wire end adapted to engage corresponding prongs fixed to the cylinder.

2. In a rotary stencil duplicating machine, in

combination a cylinder having a perforated diaphragm and an ink pad mounted on said diaphragm and attached to said cylinder by end attachment members, one of said attachment members comprising a wire over which the end of the fabric of the pad is secured, the ends of said wire comprising arms extending at approximately right angles to the portion of the wire to which the fabric is attached, and a fork at the end of each arm, a rod secured to the cylinder at one end of the diaphragm over which the fabric of the pad is extended and cnto which the forks of said arms are placed, and means for retaining the end of the pad in position with the fabric and the arms bearing on the rod.

3. In a rotary stencil duplicating machine, in combination a cylinder having a perforated diaphragm, a rod at one end of the diaphragm extending crosswise of the cylinder, an ink pad on the diaphragm and attached to the cylinder, one end of said pad extending over said rod and attached to the cylinder by means of an arm at each side of the end of the pad, said arms extending back along the sides of the pad with their ends bearing on said rod, and hooks on the cylf inder for engaging and holding the end of the pad in position.

4. An ink pad for rotary stencil duplicating machines, comprising a sheet of fabric, and an attachment member secured to one end of the fabric sheet, said member comprising a relatively long straight section of heavy wire over which the end of the sheet is secured and similar continuing relatively short sections of said wire bent inwardly at an acute angle on each side of the sheet, the ends of said short sections including a hook.

5. An ink pad as defined by claim 4 in which the opposite end of said sheet is provided with an attachment member adapted to apply a tension in the sheet and said short wire sections and comprising a U-shaped heavy wire in which the fabric of the sheet is secured to the central portion and the arms are relatively short compared to the length of the central portion of the U-shaped wire.

6. An ink pad for rotary stencil duplicating machines, comprising a sheet of fabric, and an attachment member secured to one end of the fabric sheet, said member comprising a relatively long straight section of heavy Wire over Which the end of the sheet is secured and similar continuing relatively short sections of said Wire bent at a right angle to said straight section, the extending ends of said short sections being forked so that the prongs of each fork are in a plane perpendicular to said long straight section of the Wlre.

'7. An ink pad as defined by claim 6 in which the fabric of the pad adjacent said attachment member is impregnated with an ink-resisting compound for a distance such that it extends onto the trailing end of the diaphragm of the duplicating machine which will thereby be sealed against leakage of ink past the end of the diaphragm.

WILLIAM F. HE'RTERICH.