US2007266A - Photocell control for cut-off mechanism - Google Patents

Description

- July 9, 1935.

c. P. BARKER PHOTOCELL CONTROL FOR CUT-OFF MECHANISM Filed Sept. 8, 1932 .2 Sheets-Sheet 1 July 9, 1935. c. P. BARKER I PHOTOCELL CONTROL FOR CUT -OFF MECHANISM 2 Sheets-Sheet 2 Filed p 8, 1952 Patented July 9, 1935 UNITED sTATEs PHOTOCELL CONTROL FOR CUT-OFF MECHANISM Charles P. Barker, Glencoe, n1.

Application September 8, 1932, Serial No. 632,108

60laims.

This invention relates to apparatus for automatically segmenting a continuous strip into uniform lengths or lengths bearing definite relationtures are especially desirable when used in combination with apparatus for forming a continuous strip bearing a series of designs thereon and used for making merchandise wrappers, for example wrappers for packing individual electric light bulbs and the like. It is in this connection that the invention has been illustrated.

While it has long been the practice to automatically cut a continuous strip of paper or the like into units of-a given length, and at the same time to automatically regulate the feeding of the continuous web to compensate for expansion and contraction in the material of the strip under barometric influence, and for variations in slippage or other variations in feedingthe web; correction by variation in the speed of the feeding of the web has several disadvantages, particular- 1y when the material is of a nature which necessitates handling it delicately. In the case of corrugated boarding, for example, the pressure of the feed rolls on the web must be very light, with the result that the web slips easily and is sometimes slow to respond to speed changes of the feeding rolls. Even in the case of flat paper, changes of speed are quite likely to cause breakage, which would require re-threading the web through the machine.

The present invention aims chiefly to overcome such difiiculties and to provide apparatus which will satisfactorily compensate for feeding variations when used for any material, even though it be a filmsy, easily torn paper or corrugated cardboard with the attendant problems of delicate handling.

Accordingly, the present invention proceeds upon the principle of operating the web forming and feeding apparatus as uniformly as possible and at the same time operating a periodic cutter substantially synchronously, but with automatic correction of its periodicity or speed to compensate for unavoidable variations in the feeding of the web. The automatic compensation may be accomplished by means of a minutely variable speed transmission controlled by suitable mecha=.

nism in response to impulses of an electric eye arranged to scan the moving web, though of course many other forms of compensation may be used. Such mechanism will increase or decrease the periodicity of the cutter according as it intersects the web before or after the preferred locus of severance reaches the cutter.

With these and, various other objects in view, the invention may consist of certain novel features of construction and operation, as will be more fully described and particularly pointed out in the specification, drawings and claims appended hereto.

In the drawings, which illustrate an embodi- 10 ment of the device, and wherein like reference characters are used to designate like parts,

Figure 1 is a diagrammatic side view of the il-- lustrated embodiment of the invention, indicating the circuits diagrammatically;

Figure 2 is a plan view of the structure shown in Figure 1; and

Figure 3 is a detailed illustration of one possible arrangement of the actuator.

Although my invention may take many forms, only one has been chosen for illustration. According tothis form, a continuous web I 0 of paper or corrugated cardboard or the like, is fed forwardly by feed rolls l2 which aresuitably mounted in the frame 16 of the machine as a whole. This illustrated form contemplates the use of the apparatus shown in combination with a unit for forming a corrugated strip, folding it along longitudinal lines, and joining the folded over edges by gluing a strip of tape along these adjacent edges. To prevent crushing the corrugated boarding, the upper roll I 2 is mounted in slidable bearing blocks l8 partially supported by springs 20, and limited as to downward movement by bolts 22. These rolls are preferably geared together by gears 24 and driven by a chain 26 which in turn is driven by sprocket 28 on shaft 30 driven directly by motor 32 through chain 34.

From the feed rolls the corrugated board web in the form of a folded tube is passed to the cutting apparatus which includes a cutting cylinder 36 carried by rotary cutter bar 38,-and in which one or more cutting blades 39 may be mounted in any suitable manner. The blades 39 out against a preferably smooth pressure roll 40, which is likewise mounted on the rotatable shaft 4|. Either the pressure roll 40 or the cutter rod 38, or both, may be resiliently or adjustably mounted if desired, but they are preferably pressed toward each other by stiff springs and limited in this movement by suitable screws to prevent injury to the blades. The blades 39 should contact the pressure roll firmly, but the remainder of the cylinder 36 should be of sumciently small radius not to contact the web, but to let it move freely. as

tudinally of the web by the handle 45 by means Between the feed rolls I2 and the cutter mecha nism, the web passes along a table 42 over which is mounted a scanning unit 43 which is slidable on suitable stationary bars 44 supported from the general frame I6 in any suitable manner. The scanning apparatus 43 may be shifted longiof shaft 46 and gear 41 which rotates a worm 48 engaging threads on one of the bars 44. A scale 49 may be provided to aid in setting the scanning apparatus.

The cutter unit is driven by the motor 32 which drives shaft 30 as previously stated. This shaft 30 drives the variable speed transmission device 55, the primary cones 56 of which are splined on said shaft. A belt 51 engages these cones and also engages cones 58 splined to the shaft 59, which drives the chain 60, which in turn drives a sprocket 6| mounted idly on the shaft 4|. A clutch 63 is provided for engaging the shaft 4| to the sprocket 6|. The clutch 63 is operated by a clutch fork 64 carried by a shaft 66, which is normally urged in a clutch engaging direction by a spring 61. The shaft 66 also carries a gear 68 keyed thereto, and may be rotated by a handle 69. The gear 68 is arranged to engage a gear I0 keyed on shaft 4| when the clutch 63 is disengaged. The gear '|0 normally engages a gear I2 which is keyed to and rotates the cutter rod 38. The shaft 66 and gear 68 are provided chiefly for the purpose of initially setting the cutter rod to register with a designon the web in starting the machine.

An eccentric I4 is driven from the shaft 4| through a suitable gear box I6 carried by the frame in any suitable manner. Reciprocated by the eccentric I4 is the eccentric shaft I8 which, through a rotatably mounted bell crank lever I9 reciprocates a driving rod 80. The driving rod oscillates a disk 82 which bears pawls 84 and 86 which are arranged to engage a ratchet wheel 88 when desired, being controlled in any manner described hereinafter. Ratchet wheel 88 which is prevented from unintentional rotation by spring dog 89, turns the shaft 90, which through the gears 92 turns a shaft 93. The shaft 93 through right and lefthand threads, or in any other manner desired, adjusts speed changing levers 96 which are suitably pivoted as at 98 and which adjust the cones 56 and 58. The details of the structure of the speed changing apparatus of which the cones 56 and 58 and the levers 96 and shaft 94 form a part, are shown diagrammatically or not at all, inasmuch as they are well known and may be obtained as a unit on the open market. To permit manual adjustment when desired, the shaft 94 may be provided with ahandle I00.

It should be understood that the corrugated web I0, or more exactly speaking the flat paper on the top side thereof, will be printed with a suitable design, with which design it is desired that the cutter blade should register or coincide in some particular predetermined relation. Due to variations in temperature and humidity, to slippage and to a variety of other causes, the machine once set to sever the web at the desired points will vary from the proper setting. More accurately it might be said that although the machine remains constant, the web changes in length or varies from its original movement'so that compensations in the machine are necessary. To aid in these compensations the design on the web I0 may include a transversely extending mark preferably about one-sixteenth of aninch wide (longitudinally of the web) and about threeeighths of an inch or more long (transversely of the web). desired line of severance, or may bear some definite relation thereto. According to the present invention compensation is controlled through the use of an electric eye for scanning these marks, and by providing contact means to indicate when the knife severs the sheet. The electric eye is associated with these contact means and through suitable electrical apparatus sends an electrical impulse to the contact means when each of the marks passes the spot on which the electric eye is focused. If the mark is late in reaching said spot or in other words, if the cutter is too ad- .vanced, then the impulse is directed by the contact means, which may be called a distributor, to a retardation relay system, which causes a retardation of the cutter mechanism to correspond with the lagging of the mark on the web. On the other hand, if the mark passes under the eye in advance of the time it is due (i. e., if the cutter is lagging) the distributor sends the electrical impulse to another relay system for speeding up the'cutter to correspond with the advanced position of the mark.

This compensation control is illustrated diagrammatically in Figure 1. paratus 43 includes an electric light bulb I02 from which a beam is directed by a suitable shield and lens structure I04 onto the moving web. Arranged to focus at the illuminated spot, is an electric eye unit I06 including a photo electric cell I08. When the light focused on the photo electric cell I08 is varied, the current passing from the negative lead 0 thereof to positive lead H2 and return H3 is varied, its variation comprising an electrical fluctuation which by means of a'suitable amplifier indicated as a unit by numeral I I4, causes an electrical impulse to be transmitted from a negative lead 8 through wire I20. The unit I includes suitable tubes, transformers, power connections and the like for purposes described, though for simplicity of illustration these have not been shown.

The wire I20 is connected to a distributor unit I24. This distributor unit comprises a cam I26 mounted on or turned by shaft 38 and contact springs I 28 and I29 which are both mounted on an adjustable plate I30 and arranged to normally bear against the cam I26. The cam I26 is so shaped that at one position only, namely the position shown in Figure 1, both of the contacts I28 and I29 are retracted. This position of cam I26 preferably corresponds to a cutting position of cutter rod 38. Adjustments may be made, however, by rotating the disk I30, for which purpose the screw I32 and return spring I34 are provided. Mounted on the disk I30 at a position to contact contact spring I28 when it is pressed out by the cam I26, is a contact I36 which is connected to a wire I38 connected to a retarding relay system I40. Likewise mounted on disk I30 and positioned to contact the contact strip I 29 when it is passed outward by the cam I26, is a contact I42 which is connected through a wire I44 to an accelerating relay system I46. The relay systems I40 and I46 have not been shown by the usual relay symbol, since they may include amplifiers. nected to a positive lead I41 connected to the same source as lead H8.

The relay system I40 when actuated closes a contact I48, which, through a separate circuit I50 energizes the coil I52. There is preferably pro- The scanning ap-' Both of these relay systems are con- These marks may coincide with the 65 electric eye the cutter is either vided a time switch I53 which shunts across contacts I48 to maintain this circuit closed a certain length of time (for example long enough to permit three strokes of the driving rod 80) and prevents its closure for some time, perhaps half a minute, thereafter. Energization of coil I52 draws its plunger rod I54 upwardly, swinging mask I55 out from under pawl 84, so that the latter is permitted to engage ratchet wheel 88 and rotate the same as plate 82 is oscillated by rod 80. Ratchet wheel. 88, through gears 92 causes a rotation of shaft 94 in a direction to adjust the variable speed transmission unit 55 to a slower ratio, in order to slightly reduce the speed of the cutter bar 38.

In a similar manner the energization of relay system I46 closes contacts I58 to complete a separate circuit I60 which includes coil I62. This circuit is likewise held closed by a time switch I63 and then prevented from closing for a short interval. Coil I62. when energized draws'up the plunger rod I64 which raises mask I65 out from under pawl 86, permitting the pawl to engage the ratchet wheel 88 and rotate it in the direction opposite to the direction in which it is rotated by pawl 84. Through gears 92 shaft 94 is thus I rotated in a direction to shift the variable speed transmission 55 to a faster ratio in order to slightly speed up the rotation of the cutter bar 38,

Theelectrical units have not been shown in detail, since they may take a variety of forms already well known in the art relating to photo electric devices. It should be understood, of course, that the units which have been indicated would include such'tubes, transformers, power units and other elements as may be necessary to cause an energization of the coils I52 and I62, as described.

' Operation In initially starting a machine, the web is fed through the machine and under the cutter cylinder 36 and adjusted inthe correct position for severance. The shaft 661s then pressed in, dis-.- e'ngaging clutch 63, and the cutter blade is turned by hand to a cutting position. With the parts remaining stationary, the scanning unit 43 is then adjusted by handle 45 to a position at which the electric eye unit I06 is focused on one of the marks. The motor is then started and'the machine is operated under power. As long as the marks continue to fall under the focus of the eye I06 at the same instant that the cutter blade severs the web, no adJustment is necessary and none is made. However, due to a variety of factors, the chief of which areslippage and shrinkage or expansion of. the paper facing of the web I0, the web gradually departs from correct registry e-gyith respect to the cutter blade. In other words,

60 it is found that at' the instants of severance of the web by the blade, the marks either lag behind or run slightly in advance of the focus point of the electric eye I06. It follows that, under this condition,,when the mark is under the focus of the advanced or lag-f ging its proper timing. a

Whenever any mark passes under the focus of the electric eye it causes a variation in the current flowing through the wire I I2 to the amplifier II 4. This variation causes an electrical impulse or potential to be transmitted through wire I to the distributor I24 and. more specifically to the spring contacts I28 and I28. If the cutter rod 38 is in the cutting position at the time of this 75" potential, 1. e., when the mark is focused under the electric eye, then the impulse is not transmitted, the spring contacts I28 and I29 being open. However, if when the impulse is initiated by the electric eye, the cutter blade is not in the correct position, then eithencontact I28 or contact I29 will be closed by the cam I26. If the cutter blade is relatively behind its correct timing, then the impulse will be transmitted from wire I20 through contacts I29 and I42, through wire I44 and to the relay system I46 to close contact I58 which, through circuit I60, will energize coil I62 and cause the shifting of the variable speed transmission unit 55 to speed up-the cutter blade in order that it may catch up with its prope timing with respect to the marks. On the other hand, if the cutter blade is relatively ahead of its proper timingat the instant of the impulse, the cam will have closed spring contact I28 on contact I36 so that the impulse sent over wire I20 by the electric, eye I08 will be transmitted through contacts I36 and wire I38 to the retarding relay system I40 which will close contacts I48. The closing of these contacts will complete the circuit I50, thereby energizing coil I52 and causing the variable speed transmission unit 55 to be changed in the opposite direction to retardthe rotation of the cutter blade, so that it may drop back to its proper timing with respect to the marks., From the foregoing it is seen that the invention contemplates the combination of a periodic cutter and a feed having a substantially constant drive adapted to feed the strips to said cutter, a minutely variable drive for said cutter and an automatic compensator for decreasing or increasing the periodicity of the cutter according as the cutter intersects the strips before or after the preferred locus of severance reaches the cutter.

It is to be understood that many other embodiments of the invention, including some in improved form, will be apparent, and in the course of time more will be devised by those skilled in the art. It is not desired that this invention be limited to the details described, for its scope includes all such forms or improvements as come within the spirit of the following claims.

What is claimed is:

1. Apparatus for segmenting a continuous strip in definite relation to a series of imprints upon the strip which includes: a periodic cutter; a feed having a substantially constant drive adapted to feed the strip to said cutter; a minutely variable drive for said cutter; automatic compensating means responsive to contrasting surface characteristics of a strip, located in definite relation to the cutter, and decreasing or increasing the periodicity of the cutter according as its intersection of the strip occurs before or after a predetermined preferred locus of severance reaches the cutter, said compensating means comprising electric eye apparatus for initiating an electric impulse when a given portion of the design passes into the focus of said electric eye apparatus; and a distributor comprising two independent contacts and a cam rotated with respect thereto by said cutter and shaped to open both of said contactsv when in one predetermined position, to close one contact when on one side to a,retarding relaysystem and an accelerating relay system respectively.

2. Apparatus'for segmenting a continuous strip in definite relation to a series of imprints upon the strip which includes: aperiodic cutter; a feed having a substantially constant drive adapted to feed the strip to said cutter; a minutely variable drive for said cutter; automatic compensating means responsive to contrasting surface characteristics of a strip, located in definite relation to the cutter, and decreasing or increasing the periodicity of the cutter according as its intersection of the strip occurs before or after a predetermined preferred locus of severance reaches the cutter, said compensating means comprising electric eye apparatus for initiating an electric impulse when a given portion of the design passes into the focus of said electric eye apparatus; and a distributor comprising two independent contacts and a cam rotated with respect thereto by said cutter and shaped to open both of said contacts when in one predetermined position, to close one contact when on one side of said position and the other contact when on the opposite side of said position, said contacts being connected to .transmit said electric impulse to a retarding relay system and an accelerating relay system respectively, said systems being arranged to cause the adjustment of said drive in a retarding and accelerating direction respectively.

3. Apparatus for segmenting a continuous strip in definite relation to a series of imprints upon the strip which includes: a periodic cutter; a feed having a substantially constant drive adapted to feed the strip to said cutter; a minutely variable drive for said cutter; automatic compensating means responsive to contrasting surface characteristics of a strip, located in definite relation to the cutter, and decreasing or increasing the periodicity of the cutter according as its intersection of the strip occurs before or after a prodetermined preferred locus of severance reaches the cutter, said compensating means comprising electric eye apparatus for initiating an electric impulse when a given portion of the design passes into the focus of said electric eye apparatus; and a distributor comprising two independent contacts and a cam rotated with respect thereto by said cutter and shaped to open both of said contacts when in one predetermined position, to close one contact when on one side of said position and the other contact when on the opposite side'of said position, said contacts being connected to transmit said electric impulse to a retarding relay system and an accelerating relay system respectively, said systems being arranged to cause the adjustment of said drive in a retarding and accelerating direction respectively by means of an oscillating member having a pair of pawls oppositely disposed thereon and arranged to engage ratchet members alternatively under influence of said relay'systems.

4. Apparatus for segmenting a continuous strip in definite relation to a series of imprints upon the strip which includes: a periodic cutter; a feed having a substantially constant drive adapted to feed the strip continuously to said cutter; a' minutely variable drive for said cutter; adjustment means for said variable drive, automatic compensation control means for operating said adjustment means responsive to contrasting surface characteristics of a strip, located in definite relation to the cutter, anddecreasing or increasing the periodicity of the cutter according as its intersection of the strip occurs before or after a predetermined preferred locus of severance reaches the cutter, said compensation control means comprising electric eye apparatus for initiating an electric impulse when a given portion .of the design passes into the focus of said electric eye apparatus; and a distributor controlled by the cutter for nullifying said impulse if it occurs when said cutter is properly timed, and for transmitting it to a retarding relay system if said cutter is in advance of its proper time and to an accelerating relay system if said cutter unit is lagging behind its proper time, said systems being arranged to cause the operation of said adjustment means in a retarding and accelerating direction respectively by means of an oscillating member driven continuously by one of said drives and having a pair of pawls oppositely disposed thereon and arranged to engage ratchet members alternatively under influence of said relay systems.

5. Apparatus for segmenting a continuous strip in definite relation to a series of imprints upon the strip which includes: a periodic cutter; a feed having a substantially constant drive adapted to feed the strip continuously to' said cutter; a minutely variable drive for said cutter; adjustment means for said variable drive, automatic compensation control means for operating said adjustment means responsive to contrasting surface characteristics of a strip, located in definite relation to the cutter, and decreasing or increasing the periodicity of the cutter according as its intersection of the strip occurs before or after a predetermined preferred locus of severance reaches the cutter, said compensation control means comprising detecting apparatus for initating an electric impulse when a given portion of the design passes into the control of said detecting apparatus; and a distributor controlled by the cutter for nullifying said impulse if it occurs when said cutter is properly timed, and for transmitting it to a retarding relay system if said cutter is in advance of its proper time and to an accelerating relay system if said cutter unit is lagging behind its proper time, said systems being arranged to cause the operation of said adjustment means in a retarding and accelerating direction respectively by means of an oscillating member driven continuously by one of said drives, and a member driven thereby in alternative directions through ratchet-like means operable in either direction alternatively under influence of said relay systems.

6. Apparatus for segmenting a continuous strip in definite relation to a series of imprints upon the strip which includes: a periodic cutter; a feed having a substantially constant drive adapted to feed the strip continuously to said cutter; a minutely variable drive for said cutter; adjustment means for said variable drive; automatic compensation control means for operating said adjustment means responsive to contrasting surface characteristics of a strip, located in definite relation to the cutter, and decreasing or increasing the periodicity of the cutter according as its intersection of the strip occurs before or after a predetermined preferred locus of severance reaches the cutter, said compensation control means comprising detecting apparatus for initiating an electric impulse when a given portion of the design passes into the control of said detecting apparatus; a distributor controlled by the cutter for nullifying said impulse if it occurs when said cutter is properly timed, and for transmitting it to a retarding relay system if said cutter is in advance of its proper time and to an accelerating relay system if said cutter unit is lagging behind its proper time; and driving means arranged to be driven by one of said drives and arranged to drive said adjustment means, and including two alternatively active members, one of which may be made active by the accelerating relay system to cause said driving means to operate said adjusting means in an accelerating direction, and the other being controllable by said retarding relay system to cause said driving means to drive said adjustment means in the retarding direction.

CHARLES P. BARKER.

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