US3839974A

US3839974A - Apparatus for forming perforated embossed sheet metal fin strips for radiators

Info

Publication number: US3839974A
Application number: US00341926A
Authority: US
Inventors: D Freres
Original assignee: STERLING TOOL Co
Current assignee: STERLING TOOL Co
Priority date: 1973-03-16
Filing date: 1973-03-16
Publication date: 1974-10-08
Anticipated expiration: 1991-10-08

Abstract

Web processing apparatus is disclosed for forming embossed, perforated radiator fin segments of predetermined length from a continuous web of thin flexible metal. The apparatus comprises adjustable speed feed rolls for feeding the web from a supply roll to a constant speed embossing and perforating rotary die which forms a continuous series of regularly spaced embossments and perforations in the web. First photo electrical sensing means ascertain the amount of slack in the web between the feed rolls and the rotary die and regulate feed roll speed accordingly to maintain a predetermined amount of slack therebetween. An intermittently operable cut-off knife cuts the embossed and perforated web into fin segments of precise length with each segment comprising the same number of embossments and perforations. The cut-off knife is powered separately from the rest of the apparatus and operates in response to adjustable counter means, including a second photoelectric sensing device located between the cut end of the web and the cut-off knife. The second photoelectric sensing device senses the number of perforations moving therepast and effects operation of the cutoff knife accordingly, through the adjustable counter means, to provide segments of predetermined length and configuration. Air jet means are provided for moving the cut segments along a guideway for ultimate deposit by gravity feed into stacked relationship in a U-shaped trough.

Description

United States Patent 1191 Freres 521 11.8. c1. 113/1C,83/65,83/365, 72/185, 113/113 51 1m.c1 B21d 53/02 [58] Field of Search 113/1 C, 113; 83/65, 336, 83/365, 371, 289; 72/185, 186

[56] References Cited UNITED STATES PATENTS v 3,169,432 2/1965 Hoffman et a1 83/365 3,513,741 5/1970 Shallenberg 83/365 3,650,233

3/1972 Young et a1. 113/1 C Primary Examiner--Richard J. Herbst Attorney, Agent, or F [rm-James E. Nilles [57] ABSTRACT Web processing apparatus is disclosed for forming em- Oct. 8, 1974 bossed, perforated radiator fin segments of predetermined length from a continuous web of thin flexible metal. The apparatus comprises adjustable speed feed rolls for feeding the web from a supply roll to a constant speed embossing and perforating rotary die which forms a continuous series of regularly spaced embossments and perforations in the web. First photo electrical sensing means ascertain the amount of slack in the web between the feed rolls and the rotary die and regulate feed roll speed accordingly to maintain a predetermined amount of slack therebetween. An intermittently operable cut-off knife cuts the embossed and perforated web into fin segments of precise length with each segment comprising the same number of embossments and perforations. The cut-off knife is powered separately from the rest of the apparatus and operates in response to adjustable counter means, including a second photoelectric sensing device located between the cut end of the web and the cut-off knife. The second photoelectric sensing device senses the number of perforations moving therepast and effects operation of the cut-off knife accordingly, through the adjustable counter means, to provide segments of predetermined length and configuration. Air jet means are provided for moving the cut segments along a guideway for ultimate deposit by gravity feed into stacked relationship in a U-shaped trough.

10 Claims, 12 Drawing Figures PATENIEDBCT 81914 ma s r4 SHEET 50F 9 SWHBSWQTM PMENTED 74 SHEU 8 W 9 BACKGROUND OF THE INVENTION 1. Field of Use This invention relates generally to apparatus for forming perforated embossed sheet metal fin strips from a continuously moving web of sheet metal, such strips being usable, for example, as component parts in radiator cores.

2. Description of the Prior Art Apparatus for forming perforated embossed radiator fin strips from a continuous web of sheet metal is known in the art. In some such prior art apparatus, the fin forming element (which effects perforation and embossing) and the fin cut-off element (which cuts off each finished fin) are both driven in synchronism by a common motor-driven gear train. While such an arrangement ensures finished fins of precise length, the length of the cut-off fins can only be changed by substituting different sized gears at some point in the gear train. This procedure, however, is time-consuming and requires complete shut-down of the apparatus. US. Pat. No. 3,650,233 issued Mar. 21, 1972 to Young et al. for Apparatus for Forming Sheet Metal Fin-Strips for Heat Exchangers discloses prior art apparatus of the aforesaid character. Apparatus of this character also requires a linear travel control element for regulating the size of the web loop between the stack feed element and the first stage of the forming element. In some prior art apparatus the linear travel control element employed both photoelectric sensing devices and electromechanical limit switches to maintain a web loop of desired size.

SUMMARY OF THE PRESENT INVENTION The present invention provides improved web processing apparatus for forming embossed, perforated radiator fin segments of predetermined length from a continuous web of thin flexible metal. In accordance with the present invention the means for driving the fin cutoff element are independently operable and adjustable from the means for driving the fin forming elements and other machine components, thereby enabling fins of different length to be cut whenever desired and without the need to stop the apparatus for substitution of components, such as gears. In further accordance with the invention improved means are provided to maintain slack in the web between the feed element and forming element.

Apparatus in accordance with the invention comprises adjustable speed feed rolls for feeding the web from a supply roll to a constant speed embossing and perforating rotary die which forms a continuous series of regularly spaced embossments and perforations in l the web. First photoelectrical sensing means (providing a light beam lengthwise of the web) ascertain the amount of slack in the web between the feed rolls and the rotary die and regulate feed roll speed accordingly to maintain a predetermined amount of slack therebetween. An intermittently operable cut-off knife, driven by its own separate knife motor, cuts the embossed and perforated web into fin segments of precise length with each segment comprising the same number of emboss ments and perforations. The cut-off knife is powered separately from the rest of the apparatus and operates in response to adjustable electronic counter means, including a second photoelectric device located between the cut end of the web and the cut-off knife. The second photoelectric sensing device senses the number of perforations moving therepast and effects operation of the cut-off knife accordingly, through the adjustable counter means, to provide segments of predetermined length and configuration. Air jet means are provided for moving the cut segments along a guideway for ultimate deposit by gravity feed into stacked relationship in a U-shaped trough.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of the fin forming apparatus made in accordance with the present invention, the view being taken from the operators side of the apparatus;

FIG. 2 is a plan view of the apparatus shown in FIG.

FIG. 3 is an enlarged, perspective view, taken from the operators side of the apparatus and showing a portion of the apparatus shown in FIGS. 1 and 2;

FIG. 4 is a perspective view taken from the operators side of the discharge end of the apparatus and more particularly showing the stacker for receiving the formed fins;

FIG. 5 is a perspective view of a portion of the machine which is shown generally in FIG. 3, but taken from the opposite side, that is the drive side of the apparatus;

FIG. 6 is a schematic, perspective view of the drive for the various components of the machine;

FIG. 7 is a perspective view of the cut-off knife portion of the machine, the view being taken generally from above the apparatus;

FIG. 8 is a transverse, sectional view taken generally along the line 8-8 in FIG. 1, but on an enlaged scale and showing the photocell pick-up and the cut-off knife means, certain parts being shown as broken away or removed in section for the sake of clarity;

FIG. 9 is a plan view of the mechanism shown in FIG.

FIG. 10 is a sectional view taken generally along the line l0l0 in FIG. 8;

FIG. 11 is a combined pneumatic-electric diagram utilized with the present invention;

FIG. 12 is an electronic diagram showing the pick-up and counter used with the present invention.

DESCRIPTION OF A PREFERRED EMBODIMENT WEB SUPPLY MEANS The apparatus provided by the present invention includes a supply roll stand 1 (FIGS. 1,2 & 3) on which is rotatably mounted the supply roll SR for supplying a web W of copper or other material that is to be formed, for example, into fins for a heat exchanger, or the like. As the web is fed from the supply roll, a supply roll brake SRB is applied from time to time so as to prevent rotation of the supply roll, that is to say, the brake SRB is either on or off", the brake being on" when the machine is stopped, as will more fully appear. The brake is of the air operated type, being actuated by a conventional air operated solenoid AOS4 (FIGS. 6 and 11) which may be of the type manufactured by the Skinner Electric Valve Company of New Britain, Conn.

In any event, the web of material is fed from the supply roll and forms a downwardly hanging loop L1 which is used up and then again formed as the machine operates.

WEB FEED MEANS The web is fed, that is pulled from the supply roll SR, by a pair of feed rolls FR and FR2, the roll FR being driven through a feed roll clutch FRC and forming a feeding nip with the idler feed roll FR2. The rolls are suitably journalled in conventional anti-friction bearing assemblies (not shown) in the frame 10. The feed roll clutch FRC is of conventional air operated type, such as made by the Horton Mfg. Co. of Minneapolis, Minnesota, being operated by an air operated solenoid A083 which is also of the above referred to Skinner type. More specifically, the solenoid AOS3 actuates the conventional shiftable spool type air valve 2 (FIG. 11) which directs air pressure from air conduit 3 to be directed to the clutch from a source of pressurized air 4.

ELECTRIC EYE An electric eye EE is located on the downstream side of the feed roll FR and adjacent the lower portion of the web loop L and is electrically connected (FIG. 11) to the feed roll clutch FRC. An electric eye timer T is also provided in the electric circuit. The operation generally is such that the clutch FRC stops, and consequently stops the web feed, for a period of time until the subsequent portion of the apparatus uses up the downwardly hanging loop L of web. As will more fully appear, the length of time during which the machine stops is adjustable by a potentiometer, that is to say, a condenser throws the switch of the timer to actuate the clutch. More specifically, the electric eye has two components; a sending unit 5 and a receiving unit 6 (FIG. 6) located on opposite sides of the hanging web loop L. Thus, the feed rolls for the web are alternately driven or stopped to either use up the loop L of web or permit the formation of a new loop. Driving power is furnished to the clutch FRC of the feed roll FR from an endless timing belt 7, as will more fully appear.

ROTARY DIE MEANS Mounted in the main frame 10 of the machine is a rotatably driven rotary die RD which acts on the web W to perforate and otherwise form the web into the desired shape. The rotary die RD acts in cooperation with the rotatable rotary die anvil RDA, between which the web W passes. The rotary die and anvil may be of conventional form, and die RD is rotatably driven from a toothed, endless timing belt 12, to be referred to later, and which is trained around the timing sprocket 13 fixed on the shaft 14 of the die RD. The rotary die RD and the rotary die anvil RDA have projections and indentations which complement one another in the known manner and these may be of various sizes and shape so that each can produce the desired pattern of slots, holes, or flanges on the finished fin, in the known manner. An example of such a general rotary die is shown for example in the US. Pat. No. 2,876,723 issued Mar. 10, I959 to Lawrence. The die and anvil have

constant mesh gears

13a and 13b, respectively so that the anvil is precisely driven in timed relationship with the rotary die. Both the rotary die and anvil are journalled in anti-friction bearings (not shown) located in the frame 10 of the machine.

As the formed web W leaves the rotary die, it passes to a cut-off knife means which will now be described.

CUT-OFF KNIFE MEANS As clearly shown in FIGS. 8, 9 and 10, the cut-off knife means is adapted to handle the high speed web and precisely and cleanly cut the web into precise lengths without buckling, bending or otherwise distorting the web material which is often very thin. As the knife rotates at high speed and is frequently stopped and started, as it will later appear, it is important that the inertia and momentum problems be held at a minimum.

The knife assembly includes a bar 15 which is rectangular in cross section as shown in FIG. 10 and which is journalled in anti-friction bearings 15a in the frame of the machine. The assembly also includes the knife K formed of hardened steel and recessed in the bar 15 and rigidly held therein by cap bolts 15b. The knife has a sharp edge along its length which cooperates with the freely rotatable knife anvil KA also journalled in antifriction bearings in the frame as shown in FIG. 8. By permitting the knife anvil to rotate rather than being fixed or stationary, buckling or damage to the rapidly moving thin web is prevented and furthermore, torque requirements of the knife motor KM which drives the knife bar 15 are greatly reduced. The flywheel 15c is located in the drive between the electric motor KM and the knife bar 15 and acts to smooth out the pulsations of the knife, that is to say it acts to provide the necessary inertia for the knife. The electric motor KM which drives the knife is of itself conventional and may be of the type shown in Superior Electric Company Bulletin SE-l3725 hereinafter more fully described.

The knife anvil KA may also be driven if desired, in synchronization with the knife so as to an even greater extent reduce hesitation of the web as the cut is made.

ADJUSTABLE FIN MEASURING MEANS A counter 19, hereinafter described in detail, is provided to effect cutting of fins FF of predetermined length. Counter 19 measures fin length by counting the number of punched holes in the web between the cut end of the web and a photocell pick-up unit PCU which is part of counter 19. Pick-up unit PCU then actuates the knife motor KM when a predetermined number of holes have been counted to cut a fin FF of definite length. The counter 19 comprises the pick-up unit PCU hereinbefore referred to and also comprises, as FIG. 12 shows, a power supply PS, a metric switch MS to which unit PCU feeds its signal, a preset counter PSC, operated by metric switch MS, and a reed switch RS operated by the preset counter to effect operation of a knife motor control KMC for knife motor KM. The photocell pick-up unit PCU of counter 19 is, as FIGS. 6 and 11 show, located at the discharge side of the knife K. The unit PCU has an upper leg 17 and a lower leg 17a located on opposite sides of the support table 18 (FIG. 10) which support the fiber optic members F01 and F02, respectively, between which the perforated web W passes. Unit PCU in conjunction with other components of counter 19 hereinafter described thus acts to count the number of holes for a fin of predetermined length and consequently, measures the length of the web passing through the photocell beam. As hereinafter described, the output signal from unit PCU is fed through metric switch MS to preset counter PSC to ef fect operation of reed switch RS, knife motor control KMC and knife motor KM. The sensitivity of the photocell pick-up unit PCU, more specifically the sensitivity of the photocell PC therein, can be adjusted by the adjusting knob 19a. A counter CN responsive to the number of operations of knife is provided to count the number of fins FF which are cut.

FIN MOVING MEANS As the finished fins FF are discharged from the knife K, they leave the table 18 and enter into a guideway GW (FIGS. 3 and 10) where their movement is accelerated by jets of air issuing from spaced apart air tubes AT and AT2 located above the path of the finished fins FF as they move along the guideway GW. The air blasts from the air tubes AT and AT2 act on the fins to propel and accelerate them along the guideway GW and into the stacker 20 and against stop 20a shown at the right hand side of FIGS. 1 and 2 and also clearly shown in FIG. 4. The fins then fall in stacked relationship in the U-shaped trough 20b. Suitable regulators 21 are provided in the air conduits 23 which supply the pressurized air from the source 4 to the adjustable discharge valves AV1 and AV2, that in turn supply the air to the discharge air tubes ATI and AT2, respectively.

DRIVE MEANS The power for driving the rotary die RD and the feed roll FR is obtained from the electric main motor MM (FIGS. 5, 6 and 11) which is connected to a variable speed sheave VS, which can infinitely vary the output speed of the motor MM. The variable speed sheave VS is of the conventional type in which the opposite sheave halves are spring loaded together, such as shown in the US. Pat. No. 2,475,954 issued July 12, 1949. Power is then transmitted from the sheave through a conventional endless belt 22 to a gear reducer GR which may be of the type manufactured by the Boston Gear Works Division of North Quincy, Mass. and shown for example in US. Pat. No. 2,813,435 issued Nov. 29, 1957 or in US. Pat. No. 2,868,031 issued Jan. 13, 1959. The power is transmitted from the output shaft 24 of the gear reducer GR, through timing pulley 25 (FIG. 6) on shaft 24, and the endless timing belt 26 which is trained around pulley 25. A disc type brake MB for the main drive includes a large steel disc 28 on shaft 24 and on opposite sides of which are the air operated brakes 29 (FIGS. 5, 6 and 11) that are actuated by their air operated solenoids AOSll and associate air valves 30 (FIG. 11).

The gear reducer shaft 24 is also connected to a conventional air operated clutch AOC2 (FIGS. 6 and 11) and its associated air valve 311, which may also be of the type manufactured by the Horton Mfg. Co., Inc. of St. Paul, Minnesota. The arrangement is such that either the main brake MB or the main clutch AOCZ are selectively operative. Power is furnished to the rotary die and to the feed roller by being transmitted from the endless timing belt 26 (FIG. 6) through suitable toothed timing pulleys 12a and 33a fixed on the lay shaft 32, and respectively to the timing belt 12, and an endless timing belt 33 through suitable timing pulleys 34 and 35 fixed to another lay shaft 37 mounted in the main frame, and to endless timing belt 7.

The air operated solenoids AOSl for the main brake, the air operated solenoids AOS2 which operate the air operated clutch AOC2, the air operated solenoid AOS3 which operates the feed roll clutch FRC and the air operated solenoid AOS4 which operates the supply roll brake SRB may all be of the type manufactured by the previously mentioned Skinner Electric Valve Company of New Britain, Connecticut and are of conven tional character.

ELECTRONIC CIRCUIT FIG. 12 is a circuit diagram of counter 19 and its constituent and associated components. Broadly considered, counter 19 comprises a power supply PS; a voltage regulator VR; a metric switch MS including photocell pick-up unit PCU (comprising a light source LA and a photocell PC) and an amplifier section; a preset counter PSC; a reset switch RSS; a multivibrator MV; and a reed switch RS. In operation, passage of the perforated web W through the light beam between light source LA and photocell PC gene-rates a series of light pulses which, in turn, cause photocell PC to produce a corresponding number of electrical pulses or signals which are amplified in the amplifier section of metric switch MS and supplied to terminal 6 of preset counter PSC. When preset counter PSC receives a predetermined number of such signals (the number being determined byv the adjustment thereof and selectable by the machine operator), it produces a single signal at its out put terminal 8 which is transmitted to terminal 5 of multivibrator MV. The latter then effects momentary energization of the coil RS1 of reed switch RS to effect momentary closure of relay contact RS2 of reed switch RS. Momentary closure of relay contact RS2 effects operation of knife motor control KMC which, in turn, causes knife motor KM to make one revolution and effect one cutting operation of knife bar 15. One revolution of knife motor KM also effects one operation of the spring-loaded movable contact RSS1 of reset switch RSS to effect reset of preset counter PSC and place it in readiness for its next operation.

As FIG. 12 shows, power supply PS comprises a stepdown transformer TR having its primary winding connected in series with a conventional manually operable single pole single throw on-off switch S to a suitable source of ac voltage. The secondary winding of transformer TR is connected through diodes D1 and D2, which serve as a full wave rectifier, to supply power to metric switch MS, preset counter PSC, multivibrator MV, and reset switch RSS. The power supply PS is provided with a conventional earth ground terminal EG, with a smoothing capacitor C1 and with conventional chassis ground terminal CG. That portion of power supply PS serving the preset counter PSC is also provided with a voltage regulator VR (such as a Texas Instrument type Ser. No. 74,121 integrated circuit device) and with an additional smoothing capacitor C2.

A diode D3 and a resistor R2 are connected in series with each other between diode D2 of power supply PS and metric switch MS. A smoothing capacitor C3 is connected between diode D3 and resistor R2 and chassis ground.

Light source LA in metric switch MS is connected in parallel with a string of diodes D4 which are connected through a resistor R1 between diode D2 and chassis ground. Light from light source LA is transmitted through fiber optic devices F01 and F02 to the photoelectric cell or receiving device PC. Light from source LA also impinges on a photoelectric cell PC2. The photoelectric cells PC and PC2 are connected in series with each other and through a resistor R3 between diode D2 and chassis ground. As already explained, the photocell PC is responsive to light pulses received from light source LA to provide a signal to the base of a transistor Q1 in the amplifying circuit of metric switch MS. The photocell PC2 constantly receives light from source LA and serves as a standard for regulating the shutter sensitivity of cell PC.

The amplifier section or circuit of metric switch MS is arranged as follows. The emitter-collector circuit of transistor Q1 is connected in series with a resistor R4 between the power supply diode D3 and ground. The transistor Q1 is arranged in an emitter-follower circuit and provides high input impedance for the signal to its base. A transistor Q2 is provided between diode D3 and ground and has its emitter connected to the emitter of transistor Q1. The collector of transistor O2 is connected in series with a resistor R5 to ground. Transistor Q2 serves as an amplifier for the output signal from transistor Q1 while preventing inversion of the signal. The base of transistor O2 is connected to a point between resistors R6 and R7 which are series connected between diode D3 and ground. Another transistor Q3 is connected in an emitter-follower connection between diode D3 and ground in series with resistors R8, R9 and R10. The base of transistor Q3 is connected to a point between transistor Q2 and resistor R5. A transistor Q4 is provided to receive and amplify the output signal from transistor Q3 and provide it to an input terminal 6 of preset counter PSC. The emitter-collector circuit for transistor Q4 is connected between diode D3 and ground. The base of transistor Q4 is connected to a point between resistors R9 and R10. Transistor Q4 provides a low output impedance match to preset counter PSC.

It is to be understood that there is a voltage increase across the transistors Q1, Q2, Q3 and Q4 in the direc tion of the arrows V shown in FIG. 12 when there is a light input to photocell PC.

Preset counter PSC takes the form, for example, of an electronic circuit which can be adjusted to provide an output pulse at its output terminal 8 in response to a predetermined number of input pulses to its terminal 6. Reset switch RS is connected to

terminals

2, 4 and 6 of counter 19 to enable counter 19 to be reset after a predetermined number of pulses have been acted upon. The output from terminal 8 of preset counter PSC is supplied to terminal 5 of multivibrator M\/, which may be a conventional integrated circuit type multivibrator, such as a Texas Instrument type Ser. No. 74121 device, which provides an amplified output signal across its

terminals

6 and 7 in response to an input to its terminal 5. An output across

terminal

6 and 7 of multivibrator MV energizes coil RS1 of reed switch RS to effect momentary closure of reed switch contact RS2 which, in turn, provides a pulse to knife motor control KMC. As hereinbefore explained, a single operation (closure) of reed switch RS effects a single revolution of knife motor KM. Knife motor control KMC and knife motor KM may, for example, be of a type described in bulletin SEE-13725 (MS 2105 Gl95) instructions for Installation Operation and Maintenance 3K and 5K SLO-SYN Preset Indexes issued by the Superior Electric Company, Bristol, Connecticut.

I claim:

1. In web processing apparatus for forming perforated segments of predetermined length from a continuous moving web of material: web feed means; die means to which said web is fed by said web feed means for providing perforations in said web; first drive means for driving said web-feed means and said die means in mechanically synchronized relationship; cut-off means to which the perforated web is continuously fed by said die means and operable to cut perforated segments from the perforated end of said web while said web is moving; second drive means independent of said first drive means for driving said cut'off means; and adjustable control means for directly sensing the passage of perforations in said web past a point between said cutoff means and said end of said web and responsive to passage of a predetermined number of perforations to effect a single cutting operation of said second drive means and thereby provide a segment of predetermined length.

2. Apparatus according to claim 1 wherein said control means comprises photoelectric sensing means located at said point and responsive to passage of a perforation to provide a signal and further comprises counter means responsive to said photoelectric sensing means for effecting a single operation of said cutoff means in response to a predetermined number of said signals, said counter means being selectively adjustable to change the predetermined number of signals needed to effect a single operation of said cut-off means.

3. Apparatus according to claim 2 wherein said counter means comprises a presettable counter for receiving a plurality of signals from said photoelectric sensing means and providing a single output signal in response thereto and a relay operable in resonse to said single output signal to effect a single operation of said cut-off means.

4. Web processing apparatus according to claim 1 wherein said web tends to form a loop of slack between said web feed means and said die means; wherein said first drive means includes clutch means for controlling the operation of said web feed means; and additional control means responsive to the size of said loop of slack to operate said clutch means, said additional control means comprising a light source for projecting a light beam and a photoelectric device responsive to said light beam, said light beam being disposed along and spaced from an acceptable path of movement of said web and interruptable when said loop exceeds a predetermined size.

5. In a web processing apparatus: web feed means for moving said web along a path; die means to which said web is fed for providing perforations in said web; said web tending to form a loop of slack between said web feed means and said die means; cut-off means for continuously receiving perforated web from said die means and operable to cut off segments thereof while said web is moving; first drive means for driving said web feed means and said die means in mechanically synchronized relationship; said first drive means including selectively operable clutch means for controlling the operation of said web feed means; second drive means independent of said first drive means operable to drive said cut-off means; first control means responsive to the size of said loop of slack to operate said clutch means; and second control means directly responsive to the passage of a predetermined number of perforations past a point between the cut end of said web and said cut-off means to operate said second drive means to effect a single operation of said cut-off means in response to passage of a predetermined number of perforations and thereby provide a cut segment of predetermined length.

6. ln web processing apparatus for forming perforated segments of predetermined length from a continuous moving web of material: die means for providing a continuous series of perforations in said moving web; cut-off means for receiving the perforated web from said die means and operable to cut segments from the end of said perforated web while said web is moving; and control means for directly sensing the passage of said perforations past a point located between said end of said web and said cut-ofi means, said control means being responsive to the passage of a predetermined number of perforations past said point to effect a cutting operation of said cut-off means and thereby provide a segment of predetermined length, said control means comprising photoelectric sensing means located at said point and responsive to passage of a perforation to provide a signal and further comprising adjustable counter means responsive to said photoelectric sensing means for effecting a single operation of said cut-off means in response to a predetermined number of said signals.

7. Apparatus according to claim 6 wherein said counter means comprises a presettable counter for receiving a plurality of signals from said photo electric sensing means and providing a single output signal in response thereto and a relay operable in response to said single output signal to effect a single operation of said cut-off means.

8. In web processing apparatus for performing an operation on a continuous flexible web of material: adjustable speed web feed means including a clutch for moving said web along a path; operating means to which said web is fed by said web feed means and which perform an operation on said web while said web is continuously moving; said web tending to form a loop of slack material between said web feed means and said operating means; and control means for sensing the size of said loop and responsive thereto to adjustably control the speed of said web feed means by operating said clutch, said control means comprising a light source for projecting a light beam and a photoelectric device responsive to said light beam, said light beam being disposed along and spaced from an acceptable path of movement of said web and interruptable when said loop exceeds a predetermined size, said control means further including timer means for operating said clutch for a predetermined interval of time.

9. In web processing apparatus for performing an operation on a continuous flexible web of material: adjustable speed web-feed means for moving said web along a path, said adjustable speed web-feed means comprising at least one feed roll, drive means for driv ing said feed roll, and clutch means between said feed roll and said drive means; operating means to which said web is fed by said web feed means and which perform an operation on said web while said web is moving; said web tending to form a loop of slack material between said web feed means and said operating means; and control means for sensing the size of said loop and responsive thereto to control the speed of said web feed means, said control means comprising a light source for projecting a light beam, a photoelectric device responsive to said light beam, and means responsive to said photoelectric device to disengage said clutch means to stop feeding movement of said web feed means when said light beam is interrupted, said light beam being disposed along and spaced from an acceptable path of movement of said web and interruptable when said loop exceeds a predetermined size, said control means including timer means for maintaining said clutch means disengaged for a predetermined interval of time.

10. In web processing apparatus for performing an operation on a continuous flexible web of material: adjustable speed web feed means for moving said web along a path, said adjustable speed web feed means comprising a pair of feed rolls, an electric motor for driving at least one of said feed rolls, and an electrically operable clutch between said motor and said one feed roll; operating means to which said web is fed by said web feed means and which perform an operation on said web while said web is moving; said web tending to form a loop of slack material between said web feed means and said operating means; and control means for sensing the size of said loop and responsive thereto to control the speed of said web feed means, said control means comprising a light source for projecting a light beam, a photoelectric device responsive to said light beam, and electrically operable control means responsive to said photoelectric device for disengaging said clutch to stop feeding movement of said web feed means when said light beam is interrupted, said light beam being disposed along and spaced from an acceptable path of movement of said web and interruptable when said loop exceeds a predetermined size, said control means including adjustable electric timer means for maintaining said clutch disengaged for a predetermined interval of time.

Claims

1. In web processing apparatus for forming perforated segments of predetermined length from a continuous moving web of material: web feed means; die means to which said web is fed by said web feed means for providing perforations in said web; first drive means for driving said web-feed means and said die means in mechanically synchronized relationship; cut-off means to which the perforated web is continuously fed by said die means and operable to cut perforated segments from the perforated end of said web while said web is moving; second drive means independent of said first drive means for driving said cut-off means; and adjustable control means for directly sensing the passage of perforations in said web past a point between said cut-off means and said end of said web and responsive to passage of a predetermined number of perforations to effect a single cutting operation of said second drive means and thereby provide a segment of predetermined length.

2. Apparatus according to claim 1 wherein said control means comprises photoelectric sensing means located at said point and responsive to passage of a perforation to provide a signal and further comprises counter means responsive to said photoelectric sensing means for effecting a single operation of said cut-off means in response to a predetermined number of said signals, said counter means being selectively adjustable to change the predetermined number of signals needed to effect a single operation of said cut-off means.

6. In web processing apparatus for forming perforated segments of predetermined length from a continuous moving web of material: die means for providing a continuous series of perforations in said moving web; cut-off means for receiving the perforated web from said die means and operable to cut segments from the end of said perforated web while said web is moving; and control means for directly sensing the passage of said perforations past a point located between said end of said web and said cut-off means, said control means being responsive to the passage of a predetermined number of perforations past said point to effect a cutting operation of said cut-off means and thereby provide a segment of predetermined length, said control means comprising photoelectric sensing means located at said point and responsive to passage of a perforation to provide a signal and further comprising adjustable counter means responsive to said photoelectric sensing means for effecting a single operation of said cut-off means in response to a predetermined number of said signals.

9. In web processing apparatus for performing an operation on a continuous flexible web of material: adjustable speed web-feed means for moving said web along a path, said adjustable speed web-feed means comprising at least one feed roll, drive means for drivIng said feed roll, and clutch means between said feed roll and said drive means; operating means to which said web is fed by said web feed means and which perform an operation on said web while said web is moving; said web tending to form a loop of slack material between said web feed means and said operating means; and control means for sensing the size of said loop and responsive thereto to control the speed of said web feed means, said control means comprising a light source for projecting a light beam, a photoelectric device responsive to said light beam, and means responsive to said photoelectric device to disengage said clutch means to stop feeding movement of said web feed means when said light beam is interrupted, said light beam being disposed along and spaced from an acceptable path of movement of said web and interruptable when said loop exceeds a predetermined size, said control means including timer means for maintaining said clutch means disengaged for a predetermined interval of time.