US2633195A

US2633195A - Clamp for paper-cutting machines

Info

Publication number: US2633195A
Application number: US60341A
Authority: US
Inventors: William C Rupp
Original assignee: Chandler and Price Co
Current assignee: Chandler and Price Co
Priority date: 1948-11-16
Filing date: 1948-11-16
Publication date: 1953-03-31
Anticipated expiration: 1970-03-31

Description

Mmh 31,1953 WQRUPP 2,633,195

CLAMP FOR PAPER-CUTTING MACHI NES Filed Nov. 16, 1948 3 Sheets-Sheet l INVENTOR.

WILLIAM C.RUPP

ATTORA/EYS.

March 31, 1953 w c, P 2,633,195

CLAMP FOR PAPER-CUTTING MACHINES Filed Nov. 16, 1948 3 Sheets-Sheet 2 r-g 1 L INVENTOR. WILL/AM C.PUPP

ATTOBIVE Y6.

March 31, 1953 w. c. RUPP 2,6336195 CLAMP FOR PAPER-CUTTING MACHINES Filed Nov. 16, 1948 3 Sheets-Sheet 3 INVENTOR. WILLIAM C. RUPP BY-vi ATTORNCXS Patented Mar. 31, 1953 CLAMP FOR PAPER-CUTTING MACHINES William G. Rupp, Parma, Ohio, assignor to The Chandler & Price Company, Cleveland, Ohio,

a corporation of Ohio Application November 16, 1948, Serial No. 60,341

This invention relates, as indicated, to a clamp for a paper cutting machine and, more particularly, to power-operated hold-down or binder clamp means of novel construction.

Paper cutting machines of the type with which this invention is concerned may be of the gen- 'eral form illustrated and described in Tyler et a1.

Patent No. 1,967,600 and Reichert et al. Patent No. 2,305,735, for example. In such machines a fly-wheel driven by an electric motor may be connected through clutch means with a crank adaptedv to reciprocate the knife to cut a stack of sheets. It. is necessary to clamp such stack tightly until the out has been completed and the knife withdrawn, and a hand-wheel operated screw clamp is commonly provided for such purpose. It is also known to operate such clamp through mechanism including the same clutch adapted to reciprocate the knife so that both clamp and, knife will be power operated in synchronism.

A primary object of my invention is to provide a power-operated binder clamp which will be much more rapid and efficient in operation than the common hand clamp means.

A further object is to provide for automaticactuation of such clamp in timed relation to actuation of the knife, while at the same time permitting power operation of either the clamp or knife individually, when desired.

Another object is to provide a power-operated papercutting machine of less costly construction than any known in the prior art but which will have the novel advantages indicated above.

Other objects of my invention will appear as the description proceeds.

' ticularly pointed out in the claims, the following description and the annexed drawing setting forth in detail certain illustrative embodiments of theinvention, these'being indicative, however, of but a few of the various ways in which the principle of the invention maybe employed.

In said annexed drawing:

Fig. 1 is a frontelevational. view of a paper cutting machine embodying my invention, partly broken away to show certain elements of internal construction;

Fig. 2 is a vertical sectional view taken along the line 2-2 on Fig. 1; I

Fig. 3 is a wiring diagram showing the arrangement of the electriccontrol means; and

-. Fig. 4 is-a rear elevational view of the" drive 7 Claims. (01. 164-51) mechanism of the machine showing one wellknown form of clutch and drive means for the cutter.

Referring now more particularly to said drawing and especially Fig. 1 thereof, there is there illustrated a paper cutting machine which embodies the novel features of my invention. As is conventional in such machines, a wide horizontal table I is mounted on a heavy cast frame 2 adapted rigidly to support the same. An adjustable back gauge 3 which may be of the type disclosed in' Reichart Patent No. 2,203,547 is provided together with a traveling steel tape 4 indicating the position of such gauge. A knife 5 is secured by means of. screws 6 to a knife bar I. which is mounted for vertical reciprocation in upper frame fl. A wooden knife stick 9 is inset in the upper surface of table I to avoid possible damage to the-knife.

The knife bar '1' and knife 5 are adapted thus to be reciprocated in conventional manner by means of a connecting rod l0, crank II and crankshaft l2 driven through a clutch from a flywheel t2 driven by an electric motor 49. Such clutch is adapted to be operated through a clutch lever it which may be of a dual motion safety type such as that requiring the same to be first movedto the right and then to the left to cause engagement of such clutch to reciprocate the knife bar.- When one cycle of operation has been completed, the clutch will be automatically kicked out and the knife left in elevated position.

Back gauge 3 may be shifted back and forth as desired by means of hand-wheel Liand locked in adjusted position by locking. lever it. All of the above-described mechanism is conventional in various paper cutting machines now on the market.

Referring now more particularly to Fig. 2 of the drawing, I provide a vertically reciprocable binder clamp shoe it carried by a screw ll threadably engaging nut it in such shoe which is located directly behind knife 5. As shown in Figs; 1 and 2, this shoe normally projectsslightly downwardly below the edge of knife 5 when shoe and knife are in elevated position. Screw I! is driven by a reversible electric torque motor I 9 through a speed reducer 29 carried by upper frame 8. Such motor is of a type which may be temporarily stalled without damage thereto.

Referring now to Fig. 3 of the drawing, two

parallel electric circuits are provided including relays 2i and 22 respectively operative to open and close corresponding contacts 21' and 22 for such motor L9; to reverse: the. same; Operation of relay 2| will cause screw I! to be driven in a direction to elevate binder clamp l6 and operation of relay 22 is eifective to cause rotation of screw I1 to lower such clamp.

The crank H which operates to reciprocate connecting rod l6 and thereby the knife 5, is driven by an electric motor 40 through V-belts 4i, flywheel 42, drive shaft 43, and worm and gear unit 44. The flywheel unit includes a clutch 45 adapted to be actuated through shifting of cone 46 releasably to engage flywheel 42 with shaft 46. Shifter cone 4! is likewise operative to apply brake 48 to stop rotation of shaft 43 simultaneously with disengagement of clutch 45.

Such cones

46 and 41 are adapted thus to be reciprocated by means of clutch lever l3 and yoke 49 pivotally mounted at 5!]. As previously indicated, conventional mechanism will ordinarily also be provided to ensure single-cycle operation, the clutch bein disengaged and the brake applied automatically after the knife has been reciprocated to make the cut and returned to elevated position. The particular drive means thus employed to operate the knife forms no part of the present invention.

Now considering Figs. 1 and 3 together, the remainder of the mechanism will be described in conjunction with an explanation of the operation thereof. A selector switch 23 may be turned to select either Hand or Automatic operation. When turned to Hand, switches 23A and 2313 will be open. The binder clamp l6 may now be'raised or lowered independently of knife bar I by pressing

switch buttons

24 and 25 respectively. When switch 25 is thus manually held closed, current will pass through normally closed switch 26 and relay 22 causing motor I9 to be operated to move clamp l6 downwardly. Upon pressing switch 24, current will now flow through normally closed switch 21 and relay 2| to cause motor [9 to operate in the reverse direction to elevate such clamp. When the clamp reaches fully elevated position as shown in Fig. 2, it will engage such limit switch 21 to open the same, thereby stopping the motor (since switches 23B and 25 are both open).

Now turning selector 23 to Automatic, switches 23A and 23B are both closed. After the stack of sheets 28 has been properly arranged on table 1 against back gauge 3, the operator then moves clutch lever l3 first to the right and then to the left to cause engagement of clutch and rotation of crankshaft l2. The preliminary movement of lever l3 to the right operated limit switch 29 completing the circuit through switch 23B, switch 26, and relay 22 to initiate downward movement of the binder clamp 16. It will be seen, therefore, that such clamp starts its downward movement before the clutch is engaged to rotate crankshaft I2 and crank H to reciprocate the knife. This means that the stack of sheets 28 will always be firmly clamped by the binder clamp shoe before the knife engages the same. As above explained, the motor I9 merely stalls for the brief period (about one second) which is required for the knife to make the cut and return. A cam 30 is mounted on shaft I2 to turn therewith and is positioned to engage and operate switch 26 just prior to completion of upward reciprocation of the knife after making the cut. Engagement of cam 36 with normally closed switch 26 causes the latter to open and simultaneously closes normally open contacts 26A. Opening of switch 26 de-energizes relay 22 as well as holding circuit 29', permitting switch-29 to reopen. Closing of.

contacts 26A completes the circuit through switch 23A, normally closed switch 21 and relay 2| with the result that motor I9 is now reversed to elevate the binder clamp l6. Such binder clamp is therefore not raised from the stack 28 until after the knife 5 is clear thereof. As the binder clamp nears completion of its upward movement, it engages limit switch 21 and opens the same, thereby breaking the circuit and stopping motor I9. Such interruption of the circuit likewise breaks holding circuit 26A, permitting switch 26A to reopen and switch 26 to close. Since, as above described, the knife operating clutch is automatically kicked out after completion of one cycle and the clutch handle [3 automatically returned to initial position, the entire mechanism is now set up and ready for another operating cycle.

Motor I!) may be provided with a manual control 32 of well-known type of regulating the clamping pressure by means of a variable resistance in the motor circuit. Or an adjustable friction clutch may be provided, if desired.

It will be seen from the foregoing that I have provided an automatic paper cutting machine which is exceedingly flexible in operation, permitting the knife and clamp to be reciprocated independently of each other when desired. I have found that my new machine may be operated at a rate of forty cuts per minute which is consid erably faster than the operator is able to load the same.

The electrical interconnection of the controls ensures that positive clamping pressure will be maintained on the stack from a moment before the knife begins the out until after the knife is withdrawn. The entire device is substantially foolproof and the work produced is of uniformly high quality even when employing relatively unskilled operators.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

I therefore particularly point out and distinctly claim as my invention:

1. Ina power-operated paper cutting machine having a knife, crank means adapted to reciprocate such knife, and a clutch-operating lever operative to connect such crank with drive means therefor; a reciprocable clamp adapted to clamp the work during such cutting operation, screw means threadedly engaging said clamp to thus reciprocate the same, a reversible electric torque motor mounted to drive said screw means, a switch adapted to be actuated by such clutch-operating lever when the latter is shifted to initiate reciprocation of such knife, actuation of such switch completing the circuit of said motor to drive said screw means to advance said clamp, a cam rotatable with such knife-reciprocating crank means, switch means positioned to be actuated by said cam after rotation of such crank to reciprocate such knife to make the cut and return such knife from the cut, actuation of said last-named switch means interrupting such motor circuit and completing the motor circuit effective to reverse the direction of rotation of said screw means and thereby retract said clamp, and a limit switch engageable by said clamp in retracted position to stop said motor.

2. In a paper cutting machine having a table adapted to support a stack of sheets thereon, a.

vertically. reciprocableclamp. adapted to clamp such stack on such table, and a knife operative to out such stack thus clamped; means operative to raise and lower such clamp comprising a vertically disposed screw mounted against axial movement and threadedly engaging such clamp, a reversible electric torque motor mounted to drive said screw to raise and lower such clamp, switch means automatically operable to energize said motor to lower such clamp in advance of downward cutting movement of such knife, switch means automatically operative after completion of such cut and withdrawal of such knife to reverse said motor to raise such clamp, and a limit switch engageable by such clamp in elevated position operative to stop said motor.

3. In a paper cutting machine having a table adapted to support a stack of sheets thereon, a vertically reciprocable clamp adapted to clamp such stack on such table, and a knife operative to out such stack thus clamped; means operative to raise and lower such clamp comprising a reversible electric torque motor, means driven by said motor engaging such clamp operative to raise and lower the latter as determined by control means to energize said motor to lower Q such clamp in advance of such knife, switch means automatically operative after completion of such cut and withdrawal of such knife to reverse said motor to raise such clamp, and switch means operative to stop said motor upon return of such clamp to elevated position.

4. In a paper cutting machine having a table adapted to support a stack of sheets thereon, a vertically reciprocable clamp adapted to clamp such stack on such table, and a knife operative to out such stack thus clamped; means opera tive to raise and lower such clamp comprising a reversible electric torque motor operative when driven in one direction to lower such clamp and when driven in the other direction to raise the same, control means operative to initiate reciprocation of such knife, means responsive to operation of said control means adapted to energize said motor to lower such clamp in advance of such knife, means operative after return of such knife from the cut to reverse said motor to elevate such clamp, and means adapted automatically to stop said motor upon return of such clamp to elevated position.

5. In a paper cutting machine having a clamp reciprocable into and out of clamping position, a knife operative to out such stack thus clamped; means operative to reciprocate such clamp comprising a reversible electric torque motor, drive means connected with said motor and clamp adapted to be driven by said motor and operative when driven in one direction to move such clamp into clamping position and when driven in the other direction to move such clamp into unclamped position, control means operative to actuate said motor to drive such clamp to clamp the work and to reverse said motor to drive such clamp to unclamp the work, and means automatically operative to time such actuation of said motor in relation to movement of such knife to clamp the work prior to engagement of such knife with the work and to unclamp the work only after such knife has returned from the cut.

6. In a paper cutting machine having a table adapted to support a stack of sheets thereon, a vertically reciprocable clamp adapted to clamp such stack on such table, and a knife operative to out such stack thus clamped; means operative to raise and lower such clamp comprising reversible clamp drive means, a stallable electric torque motor adapted to operate said drive means, control means adapted to energize said motor to lower such clamp, said motor being adapted to stall without harm thereto during a short clamping period, whereby such stack may be actively clamped during performance of the cutting operation, control means automatically operative to reverse said motor to raise such clamp after completion of such cutting operation, and control means automatically operative to lie-energize said motor when such clamp has been fully raised thereby.

7. In a paper cutting machine having a table adapted to support a stack of sheets thereon, a vertically reciprocable clamp adapted to clamp such stack on such table, a knife mounted to out such stack thus clamped, and separate drive means for such clamp and knife; drive means for such clamp comprising a reversible, stallable electric torque motor, screw means engaging such clamp and adapted to be driven by said motor to raise and lower such clamp, control means adapted to energize said motor to lower such clamp, said motor being adapted to stall without harm thereto during a short clamping period whereby such stack may be firmly and actively clamped during performance of the cutting operation, control means actuated by such knife drive means automatically operative to reverse said motor to raise such clamp after completion of such cutting operation and withdrawal of such knife from the cut, and control means automatically operative to de-energize said motor when such clamp has been fully raised thereby.

WILLIAM C. RUPP.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,729,582 Kast Sept. 24, 1929 2,230,802 Klein Feb. 4, 1941