US3097752A

US3097752A - Cutting knife-stack support

Info

Publication number: US3097752A
Authority: US
Inventors: Thumim Carl
Original assignee: Miehle Goss Dexter Inc
Current assignee: Miehle Goss Dexter Inc
Priority date: 1960-10-12
Filing date: 1960-10-12
Publication date: 1963-07-16
Anticipated expiration: 1980-07-16
Also published as: GB937179A; DE1134355B

Description

July y16, 1963 v c. THUMIM 3,097,752

QUTTING KNIFE-STACK SUPPORT AFiled Oct. 12,.l960 2 Sheets-Sheet 1 July 16, 1963 c. THUMIM 3,097,752

- CUTTING KNIFE-STACK SUPPORT Filed Oct. l2, 1960 2 Smets-sheet 2 INV EN TOR. CTF/H y/W//W United States Patent Omce 3,097,752 Patented July 16, 1963 3,097,752 l CUTIING KNIFE-STACK SUPPORTV `Carl Thum'im, Westbury, N.Y., assignor to Miehle-Goss- Dexter, Incorporated, Chicago, Ill., a corporation of Delaware Filed Oct. 12, 1960, Ser. No. 62,178 `9 Claims. (Cl. 214-'-1) My .present invention is an improvement, including a novel valve construction, of the invention shown in my prior Patent 2,771-,948 for a Cutting Knife-Stack Support and relates to a novel air cushion valve which will facilitate the movement of the paper stack on the table of the cutting machine as the stack is manipulated for placement and for cutting.

The primary object of my invention is the provision of a novel valve structure yfor the openings of an air cushion cutting table wherein the paper stack under surface and the boundaries thereof control the number :and distribution of the openings through which air under Vpressure is admitted to form a cushion of air under `the paper stack to facilitate the movement of the stack.

Speciiically my novel valve comprises a structure where a 4ball or other valve element is held in position by compressed air to close the opening in the table Iand prevent Vair under pressure from escaping; the ball does not project 'above the table surface. A srnall by-pass -groove in the opening permits a correspondingly small amount of air lto escape to the enclosed (tubular) passage to the `opening above the valve seat.V When any portion of the paper stack covers the opening, this small amount of `escaping air quickly, land almost immediately, builds up lan equal counter-pressure in the passage above the valve seat thereby permitting the ball valve to drop and permit compressed air to escape through the opening at the end of the small passage. 'This provides the air cushionfor the paper stack.

sectioned, of one of the valves used to control air to the plurality of ports.

`FIGURE 4 is a sectional view taken lalong line 5--5 of FIGURE 2 looking in the direction of the arrows.

FIGURE 5 is an electrical diagram showing the mode of connecting certain components of the invention.

Referring now to the drawings, there is shown as much of the construction of the cutting machine Ias isV necessary lto render the description of the present invention clear vand lucid. Brieily, the illustrative cutting machine inncludes a main frame F carrying a horizontally extendving cutting table T, a vertically displaceable cutting knife .K, la paper clamp C `arranged rearwardly of the cutting knife K and lowered against the paper lift with pressure `prior to cutting and a back gauge G selectively positioned on the cutting table T to move the paper lift into position -for cutting. The back gauge G is driven toward and `away from the knife K by A:a lead screw in' threaded engagement with an integral head on the back gauge G,

the lead screw 10 being coupled to a hand wheel 12 adjacent the `forward end of the machine and to a drive motor 14 `adjacent the rearward end of the machine.

The table T is provided with a plurality of rows of spaced ports or air exits 20, distributed uniformly about the paper supporting surface 22 of the table T. The number of ports Ztl is Kselected in' accordance with the 2 floating action required as will 'subsequently become apparent. The respective ports are interconnected by internal tubes or passageways 24 'in the table T to a common tube or inlet 26 adapted to be connected to a suitable source of air under pressure.

Specifically, an 'air pump 28 constructed Iand arranged in accordance with principles well understood per se is connected via appropriate gearing 30 to sa drive motor 32. The high pressure outlet 34 of the pump 28 is connected to a high pressure reservoir 36 and then to a low Vpressure reservoir` 38 via a reducing valve 40. 'Ilhe low pressure reservoir is connected to the 'air inlet 26 by an electrically operated three-way valve v42 normally closed and illustrated as a solenoid controlled valve having a solenoid plunger 44 arranged in controlled relation relative to the solenoid coil 46.

A suitable source of

line potential

48, 48 is provided for the solenoid coil 46 which forms part of ak control circuit arranged to coordinate the admission of air to the ports v20 in' dependence upon operation of the back gauge G, the clamp C, and cutting knife K. Specifically,

Ywhen the clamp C is brought into contact with the paper prior fto operation of the cutting knife K, it is undesirable to admit air to the inlet 24 via the normally closed yair inletvalve 42, since this might result in sidewise displacement of the paper upon engagement therewith of the clamp C. Accordingly, in circuit with a manual operators switch 50, the closing of which would 'normallyr complete the energizing circuit for the solenoid coil 46, there is provided 'a circuit breaker 52 including xed contacts 54, 54 and a movable bridging contact 56 supported on one end of a rocking lever 58 pivoted on a pin 60. A spring 62 is connected to the lever 58 and normally biases the same to the position indicated by the broken lines of FIGURE 1 wherein the circuit breaker 52 is open.

The end of the lever 58 remote from the connection to biasing spring 62 is arranged to overlie the pin 64. Therefore, as the clamp assembly moves from the inop- .erative or retracted position illustrated by the full lines of FIGURE 1 tothe clamping or extended position illusltrated by the broken lines, the lever 58 rocks in the counter-clockwise direction due to the -bias of spring 62 to open the circuit breaker 52. Since the clamp C moves downwardly just prior to .a cutting operation, it follows that Iair supply to the ports 20 will be precluded during cutting as well las clamping. Of course, return of the clamp C to the retracted or inoperative position results in a closing of the circuit breaker 52 and return to control by the manual switch 50.

A further instance when it is necessary lto preclude Iair supply to Ithe ports 20 is when the back ygauge G is in motion to position the paper relative to the knife K. At such times, floating of the paper might cause an overtravel of the paper relative to the adjusted position to which the paper is brought by the back :gauge G. To obviate this diiculty, a further switch 66 is connected .in the solenoid control circuit, this switch being connected in controlled relation to the back gauge motor 14, i.e., in electrical parallel therewith as shown in FIGURE 6, precluding the possibility of activating the solenoid coil 46 when the back Igauge G is being adjusted. As a .fur-ther, feature, the three-way valve 42 is arranged to open' 'the air inlet 26 to the atmosphere whenever the supply from the low pressure reservoir 38 is cut off, Athereby releasing any lifting pressure which might be available Iat the ports 20 of the table T as a result of prior introduction of lair under pressure to the table T.

The operating mechanism for the back gauge G, the clamp C, the cutting knife K and thetm'echanism for supplying the compressed air to the ports may be understood from the above mentioned patent and are not ret o quired for a full understanding of the present novel valve. Referring now to FIGURES 3, 4, and 5, each of my novel valves 70 is mounted in a circular opening T to form the plurality of ports 2t).

Each valve 70 comprises, in part, a bushing 71 which fits within the circular cutout in a press fit. A shelf 77 is formed internally of bushing 71 and forms the bottom Aof ball chamber 79. The lower chamber of bushing 71 receives air conduit 80. A hole 81 in shelf 77 provides a path for the compressed air from conduit 80 to the chamber 79. The top of bushing 71 is internally threaded to receive externally threaded bushing 72, which forms the top of ball chamber 79. Bushing 71 is further provided with lip 73 and groove 75. When valve 70 is assembled O-ring 74 is placed within groove v75 and bushing 72 is turned into bushing 71 until the bottom abuts lip 73. Thus, an air tight connection is formed between the bushings. `Bushing 72 is provided with an octagonal aperture 76 at its upper end.

In operation after air pressure is established, the aperture is sealed by ball 78, which is maintained in position by air pressure, as shown in FIGURE 3.

A small groove 81a, at the top of bushing 72, communicates with both ball chamber 79 and aperture 76 to provide automatic control of the position of valve ball 78 in accordance with the position of the paper stack as described below.

The ball will seat against the conical surface in which the groove 81a is cut, since it is tangent thereto and such surface is below the octagonal aperture. It should be noted that the aperture itself is not the valve seat.

When there is no stack covering the port 20, the pressure of the compressed air in ball chamber 79 forces ball 78 upwards to seal aperture 76. The small amount of air leaking through groove 81a is exhausted to the area above the ball 78. The groove 81a is sufficiently small in cross-section so that when the area above it is not closed, pressure in ball chamber 79 maintains ball 78 in closed (upward) position.

When a stack of paper covers port 20, the volume between hexagonal aperture 76 and the top of ball 78 forms a chamber of its own, as shown in FIGURE 3, with the stack closing the top of the chamber. Air escaping through groove 81 now quickly lls the small chamber until the pressure above the ball 78 will equal the pressure below the ball. The ball will, therefore, drop, due to gravity, thereby permitting free flow of the compressed air, through octagonal aperture 76, to facilitate maneuverability of the stack.

By this means, therefore, the small groove 81a provides automatic control of the position of ball valve 78. When the paper stack traps the air leaking from groove 81a, the equalization of pressures opens the valve to full flow of compressed air. When the stack leaves the opening above any particular valve, the drop in pressure above the ball 78 permits the air under pressure to close the valve. The smallness of the chamber above the ball valve 78 ensures that the opening of the valve Will occur very rapidly. Closing of the valve will also be almost instantaneous owing to the dumping of air above the ball 78 when the stack leaves the port.

In the foregoing I have described my invention solely in connection with specific illustrative embodiments thereof. Since many variations and modifications of my invention will now become apparent to those skilled in the art, I prefer not to be bound by the specic disclosures herein contained but only by the appended claims.

I claim:

il. In a paper cutting machine, a horizontal table for supporting a paper stack; a plurality of openings in said table; a valve structure for each opening; each valve structure comprising a chamber having a valve seat at its upper end, a passage between the valve seat and the opening and a valve in said chamber; a compressed air entry port into said chamber; a by-pass passage connecting the portion of said chamber below the valve seat with the iirst mentioned passage between said valve seat and said opening, wherein said stack normally covers said openings and compressed air maintains said valves against said seats until pressure is equalized on said valves due to air by-passing into said first-mentioned passages, eiective to permit opening of said valves to render air support for said stack, and wherein said valves close due to air pressure thereon when said stack is removed.

2. In a paper cutting machine, a horizontal table for supporting a paper stack; a plurality of openings in said table; a valve structure for each opening; each valve structure comprising a chamber having a valve seat at its upper end, a passage between the valve seat and the opening and a valve in said chamber; a compressed air entry port into said chamber; a by-pass passage connecting the portion of said chamber below the valve seat with the lirst mentioned passage between said valve seat and said opening; said by-pass passage having a cross-section which is relatively small compared to the cross-sections of the chamber, the diameter of the valve seat and the cross-section of the lirst mentioned passage, wherein said stack normally covers said openings and compressed air maintains said valves against said seats until pressure is equalized on said valves due to air by-passing into said first-mentioned passages, effective to permit opening of said valves to render air support for said stack, and wherein said valves close due to air pressure thereon when said stack is removed.

3. In a paper cutting machine, a horizontal table for supporting a paper stack; a plurality of openings in said table; a valve structure for each opening; each valve structure comprising a chamber having a valve seat at its upper end, a passage between the valve seat and the opening and a valve in said chamber; a compressed air entry port into said chamber; a by-pass passage connecting the portion of said chamber below the valve seat with the iirst mentioned passage between said valve seat and said opening; said by-pass passage having a cross-section which is relatively small compared to the cross-sections of the chamber, the diameter of the valve seat and the crosssection of the iirst mentioned passage; compressed air, when introduced in said chamber', driving said valve against said valve seat, wherein said stack normally covers said openings and compressed air maintains said valves against said seats until pressure is equalized on said valves due to air by-passing into said nist-mentioned passages, effective to permit opening of said valves to render air support for said stack, and wherein said valves close due to air pressure thereon when said stack is removed.

4. In a paper cutting machine, a horizontal table for supporting a paper stack; a plurality of openings in said table; a valve structure for each opening; each valve structure comprising a chamber having a valve seat at its upper end, a passage between the 'valve seat and the opening and a valve in said chamber; a compressed air entry port into said chamber; a by-pass passage connecting the portion of said chamber below the valve seat with the first mentioned passage between said valve seat and said opening; said by-pass passage having a crosssection which is relatively small compared to the crosssections of the chamber, the diameter of the valve seat and the cross-section of the iirst mentioned passage; cornpressed air, when introduced in said chamber, driving said valve against said valve seat; said by-pass passage permitting a leakage of air under pressure to said rst mentioned passage and through said opening, wherein said stack normally covers said openings and compressed air maintains said valves against said seats until pressure is equalized on said valves due to air by-passing into said rst-mentioned passages, effective to permit opening of said valves to render air support for said stack, and wherein said valves close due to air pressure thereon when said stack is removed. y

5. vIn a paper cutting machine, a horizontal table for supporting a paper stack; a plurality of openings in said table; ya valve structure for each opening; each valve structure comprising a chamber having a valve seat at its upper end, a passage between the valve seat and the opening and a valve in said chamber; la compressed air entry port into said chamber; a by-pass passage connecting the portion of said chamber below the valve seat with the rst mentioned passage between said valve seat and said opening; sa-id Ab-y-pass passage having a cross-section which is relatively small compared to the cross-sections of the chamber, the diameter of the valve seat and the cross-section of the Afirst mentioned passage; compressed air, when introduced in said chamber, driving said valve against said valve seat; said by-pass passage permitting a leakage of air under pressure to said iirst mentioned passage and through said opening; said ttirst mentioned passage, when the opening is covered by a paper stack, being iillled with air under pressure from said by-pass passage equalizing the pressure below the valve and permitting the valve to open.

6. In a paper cutting machine, a horizontal table for supporting a paper stack; a plurality `of openings in said table; a valve structure for each opening; each valve structure comprising a chamber having a valve seat at its upper end, a passage between the valve seat and the opening and a valve in said chamber; a compressed air entry port into said chamber; a by-pass passage connecting the portion of said chamberbelow the valve seat with the irst mentioned passage lbetween said valve seat and said opening; said by-pass passage 'having la cross-section which is relatively small compared to the cross-sections of the chamber, the diameter of the valve seat :and the cross-section of the tirst mentioned passage; compressed air, when introduced in said chamber, driving said valve against said valve seat; said by-pass passage permitting a leakage of air under pressure to said first mentioned passage Iand through said opening; said rst mentioned passage, when the opening is cove-red by la paper stack, being iilled with air under pressure -from said `by-pass passage equalizing the pressure below the valve and permitting the valve to open; the compressed air in said tirst mentioned passage being dumped when the paper stack leaves the opening to establish la pressure dierential which closes said valve.

7. In a paper cutting machine, a horizontal table for supporting a paper stack; a plurallity of openings in said table; la valve structure for each opening; each valve structure comprising a chamber having a circular valve seat at its upper end, a passage between the valve seat and the opening and Ia ball valve in said chamber; a compressed air entry port into said chamber; a by-pass passage connecting the portion of said chamber below the valve seat with the rst mentioned passage between said valve seat and said opening, wherein said stack normally covers said openings and compressed air maintains said valves against said seats until pressure is equalized on said valves due to air by-passing into said rst-mentioned passages, effective to permit opening of said valves to render air support for said stack, and wherein said valves close due to air pressure thereon when said stack is removed.

8. In a paper cutting machine, a horizontal table for supporting a paper stack; a plurality of openings in said table; a valve structure for each opening; each valve structure comprising a chamber having a circular valve seat at its upper end, a passage between the valve seat and the opening and a ball valve in said chamber; a compressed air entry port into said chamber; a {by-pass passage connecting the portion of said chamber below the valve seat 'with the iirst mentioned passage between said valve seat and said opening; said by-pass passage having a cross-section which is relatively small compared to the cross-sections of the chamber, the Idiameter of the valve seat and the cross-section of the rst mentioned passage; compressed air, when introduced in sai-d chamber, driving said valve against said valve seat; said by-pass passage permitting a leakage of air under pressure to said rst mentioned pass-age and through said opening; said irst 'mentioned passage, when the opening is covered by a paper stack, being lilled with air under pressure from said by-pass passage equalizing the pressure below the valve and permitting the valve to open; the compressed fair in said first mentioned passage being dumped when the paper stack `leaves the opening to establish a pressure differential which closes said valve.

9. in a paper cutting machine, a horizontal table for supporting a paper stack; a plurality of openings in said table; a valve structure for each opening; each valve structure comprising a chamber having a valve seat at its upper end, a passage between the valve seat and the opening and a ball valve in said chamber; a compressed air entry port into said chamber; a by-pass passage connecting the portion of said chamber below the valve seat with the first-mentioned passage between said valve seat Iand said opening, a closure member threadedly secured to each valve structure and having a top 'wall formed with said opening, said opening being shaped to accommodate a tool, whereby said closure members may be threadedlly adjusted into flush relationship between said top Walls land said table.

References Cited in the file of this patent UNITED STATES PATENTS 1,668,271 Fisk May 1, 1928 2,065,161 Thompson Dec. 22, 1936 2,176,307 Lamb Oct. 17, 1939 2,310,636 Howard Feb. 9, 1943 2,576,687 Krenbiel Nov. 27, 1951 2,733,960 Barford Feb. 7, 1956 2,945,600 Thumim July 19, 1960

Claims

1. IN A PAPER CUTTING MACHINE, A HORIZONTAL TABLE FOR SUPPORTING A PAPER STACK; A PLURALITY OF OPENINGS IN SAID TABLE; A VALVE STRUCTURE FOR EACH OPENING; EACH VALVE STRUCTURE COMPRISING A CHAMBER HAVING A VALVE SEAT AT ITS UPPER END, A PASSAGE BETWEEN THE VALVE SEAT AND THE OPENING AND A VALVE IN SAID CHAMBER; A COMPRESSED AIR ENTRY PORT INTO SAID CHAMBER; A BY-PASS PASSAGE CONNECTING THE PORTION OF SAID CHAMBER BELOW THE VALVE SEAT WITH THE FIRST MENTIONED PASSAGE BETWEEN SAID VALVE SEAT AND SAID OPENING, WHEREIN SAID STACK NORMALLY COVERS SAID OPENINGS AND COMPRESSED AIR MAINTAINS SAID VALVES AGAINST SAID SEATS UNTIL PRESSURE IS EQUALIZED ON SAID VALVES DUE TO AIR BY-PASSING INTO SAID FIRST-MENTIONED PASSAGES, EFFECTIVE TO PERMIT OPENING OF SAID VALVES TO RENDER AIR SUPPORT FOR SAID STACK, AND WHEREIN SAID VALVES CLOSE DUE PRESSURE THEREON WHEN SAID STACK IS REMOVED.