US2939357A

US2939357A - Cutting machines with means for automatically disabling the cutting drive and reducing the pressure of the clamp drive during replacement of the blade

Info

Publication number: US2939357A
Application number: US703787A
Authority: US
Inventors: Russell I Haywood
Original assignee: Harris Intertype Corp
Current assignee: Harris Graphics Corp
Priority date: 1957-12-19
Filing date: 1957-12-19
Publication date: 1960-06-07
Anticipated expiration: 1977-06-07
Also published as: GB844578A; DE1118746B

Description

June 7, 1960 R. HAYWOOD 2,939,357

CUTTING MACHINES WITH MEANS FOR AUTOMATICALLY DISABLING THE CUTTING DRIVE AND REDUCING THE PRESSURE OF THE CLAMP DRIVE DURING REPLACEMENT OF THE BLADE Filed Dec. 19, 1957 2 Sheets-Sheet l I6 FIG-l lNVENTOR RUSSEL I. HAYWOOD 95 70 60 62 ATTORNEYS l. HAYWOOD ANS FOR AUTOMATICALLY DIS June 7, 1960 2,939,357 ABLING CUTTING MACHINES WITH ME 4 THE CUTTING DRIVE AND REDUCING THE PRESSURE OF THE 19 l9CLAMP DRIVE DURING REPLACEMENT OF THE BLADE 2 Sheets-Sheet 2 Filed Dec.

FIG-5 by Why Mi-O I44 I45 M i T CLAMP-1P DOWN INVENTOR. RUSSEL I. HAYWOOD 2 B U MW 1 A MWMVIM. 4 w J mm Cu fl\ M ATTORNEYS United States Patent CUTTING MACHINES WITH MEANS FOR AUTO- MATICALLY DISABLING THE CUTTING DRIVE AND REDUCING THE PRESSURE OF THE CLAlVIP DRIVE DURING REPLACEMENT OF THE BLADE Russell 1. Haywood, Dayton, Ohio, assignor to Harris- Intertyp'e Corporatlon Cleveland, Ohio, a corporation of Delaware Filed Dec. 19, 1957, Ser. No. 703,787

6 Claims. (Cl. 83=-380) This invention relates to machines for cutting paper and like material and more particularly to a paper cutting machine having safety circuits which prevent operation of the cutting mechanism while the knife blade is being replaced.

In relatively large, power operated cutting machines capable of cutting through stacks of sheet material, it is necessary to replace the knife blade after it becomes dulled from use over a period of time. Since this knife is heavy and somewhat awkward to handle, it is preferable for safety reasons to have some means to raise and lower the knife into position without unnecessarily risking injury to the operator. Also, it is desirable that the cutting mechanism be positively stopped from operating during the time the operator is replacing theknife to eliminate any possibility of the machine being accidentally actuated and possibly injuring the operators hands or arms. A hydraulically operated clamp is used to hold the material in position for cutting by the knife, and is usually employed, while operating slowly under comparatively low pressure, as a lift device for lowering the dulled knife and raising a new one into position for securing to the knife operating mechanism. i a

It is therefore a principal object of this invention to provide a machine for cutting sheet materialsuch as paper in which supporting members are provided for attachment to the clamping member to support the knife blade and to deactivate the knife operating mechanism so that no accidental operation can take place.

It is another object of this invention to provide a machine for cutting sheet material such' as paper and the like in which the knife operating mechanism is positively locked in inoperable position during replacement of the knife blade.

Another object of this invention is to provide in a machine for cutting paper and the like electrical control means that are interrupted during the changing of the knife to'prevent the application of operating forces to the knife operating mechanism.

A further object of this invention is the provision of a machine for cutting sheet material of paper and the like having'a clamp which is operable only-under relatively low hydraulic pressure when the cutting mechanism is rendered inoperable.

Other objects and advantages of this invention will be apparent from the following description, the accompanying drawings and the appended claims.

In :the drawings:

'Fig. 1 is a schematic. front-elevation of a cutting machine according tothe invention showing the control panel with the knife supporting members stored therein;

. Fig. 2 is a schematic side elevation of the apparatus of.Fig..1 showing the relative positioning of'the knife bladelandfthe clamp;

,Fig. 3 is .an enlargedfragmentary view of the knife bladefandthe clamp with the supporting members in position to receive the knife, the dotted portion indicating the position of the clamp when the knife is removed a Referring to the drawings, which disclose a prefer-red embodiment of the invention the cutting machine comprises a base 10 having integral side frame members 11 and 12 respectively, providing mountings for various operating parts of the machine. A work table 15 is supported on the frame, overhanging the frame at the forward or operators side and providing a suitable support for receiving the material to be cut.

Front guides

16 and 17 are mounted to form guide channels merebetween for guiding and directing the movement of knife bar 20. A tie piece 21 joins the guide members at their upper ends and extends across the entire width of the machine providing additional strength and rigidity.

The knife bar 20 has pads or guide surfaces 22 formed thereon at either end, parts of which travel in the spaced guides formed by

members

16 and 17. The knife bar has a bevel at its lower side as shown at 25 (Fig. 2) to which the cutting knife blade 26 is secured by means of bolts 27 recessed into the knife bar.

The mechanism for actuating the knife is such that the cutting forces areapplied substantially within the plane of movement of the knife by means of a simple arrangement of links and levers, giving a high rate of knife movement and at-the same time avoiding lateral thrust on the knife blade or on the knife bar which would interfere with uniformity of cutting or result in unnecessary or excessive wear. a

For this purpose downwardly extending

arms

30 and 31 are formed at opposite ends of the knife bar, these arms being apertured to receive

pins

32 and 33 therein, and the pins being mounted, as shown, adjacent and approximately in the plane of the lower edge of the.

knife. The connections for the opposite ends of the knife are arranged to provide a double shear operation. That is, the knife moves downwardly and laterally during the cutting stroke, but since the opposite ends of the knife are at different initial elevations above the cutting table, one end moves downwardly to a greater extent by means of pin 37 to one arm of a three arm bell crank 40 which is pivotally mounted in the frame 11 for rotation about the axis of pin 41. A suitable projection at the read side face of the knife bar travels in the guideway 42. a e

The oppositeend. of the knife bar is connected by means of link 45 to pin 33, such link having an adjustable threaded connection 46 by means of which its efl:'ec-. tive length can be varied. At its lower end link 45 is secured by pin 47 to one arm 48 of a two arm bell'crank 49pivotally supported in frame 12 by means of pin 50,

Patented June 7, 1960 This link has an adjustable. threaded connection 36 by means of which its length can be changed, and its lower end is pivotally connected A sseeadsrm s1 erasures bell crank '40 receives apin 52 which secures a cross bar 55 thereto, this bar having a pivoted connection as shown at 56 with the lower arm 57 of the two arm bell crank. Thus, as shown "in Fig. l, the two bell cranks are caused to swing in unison through thecross bar 55, each bell crank causing the actuation of a corresponding end of the knife her through a difierent path of movement by bringing its associated end of the bar into a horizontal position at V the limit of its down stroke,

The operation of-the knife bar 20 is effected by means of a connecting rod 60 attached to the third arm 61 of the three arm bell crank 40. The connecting rod is driven from a crank pin 62 carried on crank plate 63 suitably mounted in the lower frame of the "machine.

The drive mechanism is shown in Fig. 4, where the main shaft 65 is shown as rotatably' supporting the crank plate 63. l i

wheel 68511155 gear assembly being mounted for rotation on a stationary'shafit 70. Gear wheel 68 is driven from a pihion 71 mounted on a counter shaft- 72 which is V rotatably supported in theframe-of the machine.

Power is supplied from a drive motor 75 located at the rear of the machine and, for convenience, supported on-the rearwardly extending end of the fixed shaft 70. The motor has a drive pulley 76 over which operates a plurality of V-belts '77 which frictionally engage the outer circumference of a flywheel 80, transmitting driving torque thereto. Flywheel 80 is carried on ashaft 81 which-thus serves as 'a drive shaft, being coaxial with,

but spaced fiforn counter shaft 72.

Clntch; and brakemechanisms l V trolling the interconnectionof. the drive shaft 81 and counter shaft 72, the clutch 'beingshown at 82 and the brake being indicated at 8 3. The clutch is electromag- V netso that it can be engaged bybfiergization of its wind-' lugs to operate the cutting mechanism any time power is. supplied to the machine.

fAlso secured to main shaft 65 isja. cam' shaped safety 7 plate '85-which rotates with, the shaft. A safety 'latch' p'in 86 is arranged to project into the path of travel of plate 85 and interfere with funther rotation thereof should there be a malfunction in' the machines operating.

mechanism. 'As noted, the safety latch is operated by means of-a solenoid 87 enabling latch 86 to be auto "mat'ically withdrawn from projection into the path 'of' plate 85 upon 'e'nergization of 'motor 75 a cuttin'gl'or tfimming relatively thick stacks or piles of paper'materials it is essential that the stack be held afiiredposition during the operation of knife bar 20 so that-the sheets will'all be of: the same dimensions with n no torn or "ragged'edges. Accomplishment of thispurpose is normally achieved by a clamp 90 which reciproare provided for con-' wise power is available for raising the clamp to its elevated position above the work material on-the table.

The hydraulic system providing for operation of clamp 90 is shown in Fig. 7 where hydraulic cylinder 105 with piston 106 is shown in diagrammatic form. Hydraulic pressure is created within the hydraulic system by means of pump 110, the pressure developed by'thepump within I the system being determined by means'of relief valve 111 which has one side co nnected to'a lower pressure Shaft '65 rotated by a gear 66 secured thereto and" operated by a pinion 67 which is secured to a large gear return system; or tank T. A valve 112 and a pressure gage 113 have been operably connected to the hydraulic circuit by conduit 114 which taps into the conduit 1 15.

co'nnecting'the' pump 110. with relief valve 111. Placed within the fluid conducting system between the fluid pump and hydraulic cylinder 105 is a check valve 116 which prevents reverse flow'of fluid toward the pump and a pair of

flow control valves

120, 121 which are connected in conduits 1'22, 123, the latter two conduits connecting the hydraulic cylinder with a reversing valve 125.

The valve 1'25 is operated by a solenoid 126 to determine the direction of fluid flow through the valve for up "and down movement of piston 106." The valve as shown in the drawings is in a position causing fiow'of hydraulic V fiuid into the top of cylinder 105 so that the'fluid contained in the bottom of the cylinder is escaping through v conduit .1 23 to tank T for recycling by 'pumplllll.

Since it is sometimes desirable for the clamp to be operable under a relatively low pressure as compared with the relatively high hydraulic pressure used when the clamp is holding a stack of material against the working table,

an additional' hydraulic line 127 is provided in which a V dump valve 130'is connected into the system; through a needle v'alve 1 3 1, and operation of valve 130 is con-- trolled by means of a solenoid 132. The pressures in cates toward and away from work table 15 adjacent the knife bar 20. The close proximity of knife bar 20 and clamp 90 is readily seen "by reference to Figs. 2 and 3.

Operation'of theclam'p is produced by means of parallel linkage such as shown'in detail in 'Patent No.'2,599,59 l. This linkageincludes downwardly extending arms 91 ahd' belt-crank levers, 97,: 98"respec'tively. Lever 97 is pivotally supported on "the A forward end of stationary shaft fwhileflever 98 ispivotally mounted on pin 1 00 su blysupportedfinside frame 1'2. V V

e'ba' '101 joins 'theoppositeends'ofthe bell 'cranks for corresponding movement, and power is applied thrpugh alink 102 pivotally attached at 103 to bellcr'ank' 98 A'hydr'aulic cylinder r05 having'a movable piston 'sreia is pivotally attached to'the link 102 by means i107: thisfmechanis'm actuating power l-able o the lam to hold it 'in contact with the rte be cut with "a preueter-mi ed rorc'e, and like- -l1'av'ing links :19}, '94 "pivotally secured to their; 7 lower ends. rPins 9 5; 96 secure the" links to the arms of the hydraulic system are so controlled that'ther'e is at all times a minimum operating pressure in the main line 115 sufficient to hold clamp 90in its uppermost position without assistance from any mechanical holding or loclc ing means. This lower or minimum pressure is maintainedfwhen replacement of aknife' blade 26'is to' be effected, since the operator is working directly withthe knifeduring this period of time andaccidental operation 'of the clamp under high pressure serious injuiy to the operator.

could result in Due to the inherent danger in cuttmg machines of the nature described/many safetyprecautions have been in-- corporated when building the machines to prevent -ac-* cidental operation of the knife blade and to require that the operators hands and armsbe completely removed fromthe vicinity oftheknife blade b'efore operation can take place. An example of'onesuc'h safety device is the safety latch 86 mentioned earlier. Obviously when a a blade becomes sufficiently dulledthat it needs replacement the operator must handle the heavy awkward blade,

position such that the supporting 'members'135 are im- -rriediately beneath the blade to provide support. Such an arrangement is indicated in Fig. 3 wherein the supporting members .135 are shown in the position they would asslime during the removal of blade '26from knife bar 20.

If the knife driving mechanism were to be actuated when the supporting members are "threaded into clamp 90, a great deal of damage could be done to the cutting and clamping mechanisms, and since the operator's hands are apt to be in the vicinity he could be -severely'injuried.

Therefore, the present invention provides an electrical circuit which is tied in with thedfiving motor circuitand 182 and throw switches into a closed position.

the hydraulic circuit to preclude the actuation of the cutting bar 20, and to permit the operation of clamp 90 under low hydraulic pressure only.

Referring to Fig. 6 the power input lines L1, and L2 have a number of parallel circuits extending therebctween. The first parallel circuit line 140 contains a suitable ofi-on main control 141, a control relay 142 and one set of its relay contacts, 142a. This circuit 140 is initially energized through line 143 by closing the series connected

switches

144 and 145 therein. The line 143 provides a by-pass for relay contacts 142a until such time as the relay 142 is closed, thereby closing the contacts and loci-.- ing the circuit into operation. Circuit line 146 is normally open until series connected

switches

147 and 148 are closed to complete the circuit through a normally closed clamp control switch 149, a second set of relay contacts 142b, and a second control relay 150. Upon closing of control relay 150 its relay contacts 150a in line 151 are closed to by-

pass switches

147 and 148 and lock this circuit into operation. A third circuit line 155 is energized upon the closing of control relays 142 and 150 (which close their respective relay contacts 1420, 15%), and series connected

switches

156, 157, these latter switches being closed simultaneously with

switches

147, 148 and opening of

switches

144 and 145.

Also contained in line 155 is a second pair of series 7

connected switches

158, 159 energization of which causes actuation of clutch 82. Connected in parallel with the three prior circuits is a circuit line 165, which has relay contacts 150a controlled by a relay 150, so that this circuit will not be energized'until circuit v146 is also energized. Upon closure of contacts 150a energization of the solenoid 126 occurs to throw valve 125 into a position causing fluid pressure to be supplied to cylinder 105 through conduit 123 to force piston 106 upwardly causing downward movement of clamp 90. 7

Circuit line 170 also extends between power input lines L1 and L2 and it contains a pair of series connected

switches

158a, 159a which are operated simultaneously and in unison with

switches

158, 159 so that the safety latch solenoid 87 will also be deenergized. The safety latch 86 then cannot be withdrawn and movement of the knife bar operating mechanism is prevented. To insure that solenoid 87 cannot be accidently energized, circuit 170 includes relay contacts 150d, thus requiring that control relay 150 be closed before solenoid 87 can be energized to withdraw safety latch 86 from engagement with safety plate 85. A final circuit line 175 is joined to circuit 170 on the output side of switches158a, 159a so that opening of these switches will cause interruption of solenoid 132 which controls the operation dump valve 130. When this solenoid is deenergized the dump valve is arranged to provide only a low hydraulic operating pressure to clamp 90.

The

switches

158, 158a, 159, 159a are present in the form of double pole-single throw switches located within a control box 180 (Fig, l) which is secured to the front of the cutting machine. During normal operations the supporting members 135 are stored in control box 1 80 so that the ends will force against the contact buttoms 181, While the

circuits

155, 170 are illustrated as being interrupted upon removal of the knobs or supporting members 135 from box 180 through opening of the double pole-single throw switches, it is possible for other circuit interrupting means to be used in conjunction with supporting members 135.

When replacement of a knife blade 26 becomes necessary the operator removes supporting members or knobs 135 from control box 180 thus interrupting the two

electrical circuits

155 and 170,

deenergizing solenoids

87 and 132. With deenergization of circuit 155 the clutch 82 cannot be used to connect motor 75 to main shaft 65 and effect operation of the cutting mechanism. Concurrent with removal of the clutch from the operating circuit, both

solenoids

87 and 132 are deenergized so that knife safety latch 86 cannot be withdrawn from locking engagement with plate and dump valve is opened to reservoir or tank so that only the low operating pressure is available to clamp 90.

Once removed from control box 180, knobs 135 are placed on clamp 90, after it has been lowered under the lowv pressure to its lowermost position and clamp switch 149 thrown to open circuit 146 and deenergize the control relay 150. This opening all of the relay contacts 150a-d. The opening of relay contacts 150:: removes solenoid 166 from the circuit and reverses valve 125 to cause flow of hydraulic fluid, through conduit 122 into cylinder 105 and through conduit 123 from cylinder 105. Thus piston 106 moves into cylinder 105 and the clamp 90 moves upwardly towardcutting bar 20.

The upward movement of the clamp is continued until supporting members 135 reside just beneath knife blade 26, as shown in Fig. 3, so that the bolts 27 in the knife bar 20 can be safely and easily removed without any fear that the blade will drop and injure the operators hands or arms Once the old blade has been removed a new one can be substituted, the supporting members 135 are returned to control box where they will close

switches

158, 158a, 159 and 159a, and thus the electrical and hydraulic circuits, are restored. Additionally, when the supporting members are stored within the control box they will always be readily. available when needed.

While the form of apparatus herein described constitutes a preferred embodiment of this invention, it is to be understood that this invention is not limited to this precise form of apparatus and that changes may be made therein without departing from the scope. of the invention which is defined in the appended claims. 7

What is claimed is:

1. In apaper cutting machine having a removable knife blade and an adjacenthydraulic motor operated clamp for holding a pile of sheet material in position for cutting and including a member attachable to the clamp for temporarily supporting the knife blade while effecting replacement thereof, the combination comprising a hydraulic circuit including control means providing relatively high and low operating pressures to the clamp motor for actuation thereof under high and low power selectively, driving means for actuating said knife on a working stroke, an electric circuit including first means for operating said knife blade and second means controlling the hydraulic pressure supplied to said clamp, switch means connected in said electrical circuit to control the operation of said first and second means, and means mounting said switch means on the cutting machine for operation by said supporting member to cause disabling of said driving means and operation of said control means to provide low pressure only to the clamp motor when said supporting member is attached to said clamp for use in supporting said blade thereon during replacement thereof.

2. In a machine for cutting sheet material, the combination comprising a work table for receiving a pile of sheet material, cutting means including a replaceable knife blade movable toward and away from said table for cutting said material, clamp means adjacent said cutting means for holding said pile in position on said table while said cutting means is operating, a supporting member attachable to said clamp for supporting said blade during replacement thereof, a hydraulic circuit including means providing relatively high and low operating pressures to said clamp means for actuation thereof, driving means including a selectively controlled clutch therein connected to actuate said cutting means, an electric control circuit including means controlling actuation of said clutch, means in said circuit for controlling the hydraulic pressure supplied to said clamp, a control box on said machine including a storage place for said supporting member, switch means operably connected to control the supply of electrical power to said electric circuit, and means supporting said switch means within said. control box inlposition for actuation in response to presence of said supporting member to alter the power supply to said; cir-f cuit to'cause the disabling of" said driving means when. said supporting member is removed from said control box and mounted on'said clamp and to prevent application of high pressureto said clamp means, 1

3 In 'a paper cutting machines includingsa removable reciprocable knife and an adjacentv hydraulically operated clamp for holding a pile of sheet material in position for" cutting by the..knifeand including also a support member attachable. to. the clamp for temporarily supporting the knife while effecting replacement thereof,-the combination of driving means for said knife, separate hydraulic driving means for said clamp, selective means establishingrhigh' 7 and low hydraulicpower supplies for said clamp driving means, means on said machine defining a storage station for said support .member, control means, adjacent .said storage stationflresponsivetto presence of said member at said station to, actuate said selective means to establish said highpower supply for said clamp driving means and also to providepower for saidknife driving meansfand said. control means being responsive to removal'fof saidv support member to actuate said selective means to establish and maintain said low power supply fortsaid clampi driving meansfand also to maintain said knife'driving' means in a disabled condition. 1

4.1 In afpaper cutting machines including-a removable reciprdcable knife and anadjacent clamp for holding a pileofsheetrnaterial in position for cutting bythe knife. and including also a support member attachable'to the; clamp for temporarily supportingthe knife while eifect-f 7 ingreplacemen't thereof, the combination of driving means for said knife, separate driving means for saidrclamp, 'selectivetme'ans establishing high and lowrpower supplies meansadjabent said storage station connectediwith said seleetivejmeans for operation, by saidsflpPQtt memberv in' said storage station to'actuate said selective means to establish said high power supply for said clamp driving means, and also ,to provide power for said knife driving for said .clampfldriving means, means on saidmachine 6 defining a storage station for saidfsupport membencontrot means, and saidl'control means being responsive to; ree 45 moval of said support member fromv said storage stationto estaolishsaid; low power supply for said clamp driving means andalso to disable said knife driving means.

Sgln apapercutting, machine including a removable reciproeable knife and an adjacent clamp for holding a;

8: pile of sheet material in position for cutting, by the knife and including also a support member attachable to the clamp for temporarily supporting the knife while efiect-V ing replacement thereof,- the combination of driving means operative to reciprocate said knife in response to 'selective control thereof, separate selectively operable drive means for said clamp, selective means establishing high and low power supplies for said clamp driving means, latch means operative to prevent reciprocation of said knife and including afcontrol: therefor operable with said knife driving means'to release said latching means during 'a deliberate operation of said knife, means on said machine defining a storage station forsaidfsupport member, control means connected to actuate said selective means to establish said high powersupply for said clamp driving' means and also to providetpower for said knife driving means,;and a member in said control means responsive to transfer of said support memberrfrom said storage station to said clamp ,for'actuating said control means to establish said low power supply for said clamp driving means and also to disable said knife driving means and prevent release of, said latch means,

6; In a paper cutting machine including a removable reciprocable,knifenand an adjacent clamp for holding a pile of sheetmaterial in position for cutting .by the knife and including also asupport member attachable to the. clamp for temporarily supporting the knifewhile eflecting 'replacementthereof, the combination of driving means operative to reciprocate'said knife in response to selective control thereof, separate selectively operable drive means for said clamp, selective means establishing high and low power supplies for said clamp driving ,rneans, means on said machine defining a, storage station References Cited in the file of this patent UNITED STATES PATENTS" 1,743,946 Williams-Ha Jan; 14, 1930 2,578,317 Pealer Dec. 11, 1951 2,713,407 Miller July 19, 1955 i i i