US2796480A

US2796480A - Disc type electric pickup for strip cutting machines

Info

Publication number: US2796480A
Application number: US511959A
Authority: US
Inventors: Jr Charles H Knorr
Original assignee: Individual
Current assignee: Individual
Priority date: 1955-05-31
Filing date: 1955-05-31
Publication date: 1957-06-18
Anticipated expiration: 1974-06-18

Description

June 18, 1957 c. H. KNORR, JR

msc TYPE nmcmxc PICKUP FOR STRIP cu'rrmc uncumss Filed May s1, 195s 2 Sheets-Sheet 1 FlG.i

CHARLES H; KNORR, 012.

IN V EN TOR.

June 18, 1957 c. H. KNORR, JR 2,796,430

DISC TYPE ELECTRIC PICKUP FOR STRIP CUTTING MACHINES Filed May 31, 1955 2 Sheets-Sheet 2 FIG.4

FIG. 5 O

qg 7 s4 56 5 ss 8 4 \oo "i6 TIH-P f 74- 1oz INVENTOR.

CHRRLES H. KNORR JR.

United States Patent DISC TYPE ELECTRIC PICKUP FOR STRIP CUTTING MACHINES This invention relates generallyto strip cutting machines, and pertains more particularly to a machine of the foregoing character having incorporated therein improved electrical control apparatus for sequentially m1- tiating a severing operation at preferred locations along the strip.

While the present invention may be employed in conjunction with a variety of automatic strip cutting devices, it possesses especial utility in association with automatic machines designed for handling a long strip of narrow paper on which numerous photographic prints have been made. To sever the long strip into individual pictorial prints the strip is advanced in a longitudinal direction, stopped at correct locations for the cutting operation and then moved again, such action being repeated in a cyclic manner. Since the individual prints are to have uniform margins at the top and bottom of the picture, thus denoting quality work, it is necessary to control the stoppages rather precisely. This is done by means of an electrically conductive line or mark placed on one side of the paper strip duplicated at the proper intervals, these spaced marks bridging transversely spaced electric pickup brushes. Closure of the circuit in this way energizes associated actuating apparatus for both braking and cutting the strip.

Since the reliability of a system such as that described above is dependent upon the transmission of an electrical signal or pulse to the control equipment, it is essential that the brushes make good electrical contact with the conductive workings. To do this the pickup brushes in the past have been rather heavily biased against the strip material. This has the attendant disadvantage of increasing the friction between the brushes and the paper. Consequently, the brush wear has been execessive. In one machine currently available the contact members or brushes are embedded in a plastic plate, the upper surface of which is at table level and across which the strip is constantly moved. Just the friction produced by this rubbing is sufiicient to wear rapidly the brush or contact members to such an extent that their contacting surface is below the table top. As already stated, firm electrical contact is essential in this type of operation, and in the machine referred to which is now on the market the brush assembly has to be replaced several times a day, resulting in excessively objectionable down time of the machine.

Having presented the preceding explanation to introduce the reader to the salient problems that have plaqued users of this type of equipment, it may be stated that one important object of the instant invention is to provide a strip cutting machine that will be highly satisfactory in its operation, requiring markedly little maintenance and hence involving practically no down time during shift operations.

While the existence or occurrence of wear has been invention, it is also within the contemplation of the invention to adjust in a facile manner for that wear that does take place over a period of time.

Not only does the invention comprehend a structural arrangement that provides good electrical contact with a minimum of friction, but provision is made for a pickup involving the utilization of multiple or parallel electrical paths, such a realization being possible by the inclusion of a number of contact discs or circular plates in making up the pickup drum and lengthening the conductive lines on the strip to make it coextensive with the length of the stacked drum. It might be pointed out that such a versatile arrangement facilitates any electrical relaying that might be needed for the energization of the solenoids employed in the braking and cutting operations, for the utilization of multiple electrical pickup paths makes available greater magnitudes of pickup current because of less contact resistance.

Other objects will be in part obvious and in part pointed out more in detail hereinafter.

The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereafter set forth and the scope of the application which will be indicated in the appended claims.

In the drawings:

Figure 1 is a side elevational view of a strip cutting machine having installed thereupon electrical pickup apparatus falling within the comprehension of the invention;

Figure 2 is a top plan view of the pickup apparatus, the cooperable roller being removed and the strip being shown in phantom outline so as to picture more clearly the general appearance of said apparatus;

Figure 3 is a side elevational view, partly in section, taken in the direction of line 3-3 of Figure 2 and thus in effect constituting a fragmentary enlargement of the machine depicted in Figure 1;

Figure 4 is a sectional view taken in the direction of line 44 of Figure 3, thereby picturing one end of the pickup apparatus, and

Figure 5 is a sectional view taken in the direction of line 5-5 of Figure 4 to show the stacked construction of the pickup drum.

Referring in detail to the drawings and specifically to Figure 1 for the moment, a strip cutting machine exemplifying the invention is shown in suflicient detail to enable the invention to be readily understood. From this view it can be seen that the machine comprises a work table 10 over which is moved a strip 12 of photographic paper having a series of printed pictures thereon. Operatively associated with the table 10 is a solenoid actuated brake mechanism 14 functioning to stop the travel of the strip 12 at desired intervals and a solenoid actuated cutting knife 16 designed to sever the strip when braked. At the discharge end of the table is disposed a receptacle 1-8 into which the cut prints may fall.

The pickup apparatus for controlling the

mechanisms

14 and 16 is designated in its entirety by the reference numeral 20. As can be seen from an inspection of Figures 2-4 this apparatus includes a base plate 22 fitted into a flanged opening 24 in the table 10 and held in place by a plurality of screws 26. Secured to the detachable base plate 22, as by additional screws 28, is an L-shaped member providing an upstanding post 30. This post supports a pin 32 on which is pivotally mounted an arm 34 having journaled at its distal end a roller 36. By reason of a torque spring (not visible) the arm 34 is biased in the angular direction designated by the arrow 38 (Figure 3) so as to cause the roller 36 to bear downwardly against the upperside of the strip 12.

Depending downwardly from the bottom of the base plate 22 is a pair of bolt members or guides 40 with nuts 42 threaded onto their lower ends. these guides 40 is to resiliently support a pickup drum 44 which bears against the underside of the strip 12, access to this underside being by reason. of an opening 46 provided in the base plate 22.

Before continuing with the description of how the drum 44 is resiliently supported, the invention probably will be better comprehended by revealing-the mechanical and electrical construction of the drum. To this end, attention is now directed to Figure 5. In this figure it will be discerned that the drum 44 is composed of two metallic heads 48 and 50, the head 48 having integral therewith av cylindrical portion or sleeve 52 about which is circumposed a series of metallic discs or annular plates. Close study of Figure will disclose that these discs con.- stitute two alternate groups 54' and 56 separated axially by interposed washers 58' of electrically insulating material The annular plates constituting the group 5'4, it will be noted, have a bore or internal diameter 60 larger than the diameter of the sleeve 52, whereas the inner diameter 62 of the other group 56 is the same as the sleeve so that there is provided actual contact therebetween.

Each plate is provided with quadrantly spaced apertures through which extend equal studs or stay bolts 64 (four -in the present instance). The apertures of the plates 54 have been given the reference numeral 66 and it will be observed that they are of the same size as the shank of the stud 64, but the other apertures, that is those in. the plates 56 and designated by the numeral 68, are larger in diameter, thus obviating the contact of these plates with the studs 64. Also, itis to be noticed that the apertures in the head 50 are countersunk (see the one in Figure 5) so that the enlarged end 70 of the stud is in direct contact with the said head 50, while in contrast to this arrangement the aperture in the head 48 accommodating the enlarged end 72 of the stud 64 is of sufii'cient dimensions so that there is ample clearance and hence no contact or engagement. By virtue of this construction and arrangement of parts it will be recognized that the group 5.4 of plates is electrically connected to the head 50', and the group 56 to'the head 48, the two heads being electrically'insulated from each other by reason of the disposition made of the washers 58.

Flanking each end of the drum 44 is a pair of thrust washers 74 through which project oppositely issuing

stub shafts

76 and 78, these stub shafts being. press fitted into The role played by i recesses bored, respectively in the two heads. The. outer ends of. the shafts 76' and 78 are journaledin a pair of sleeve bearings 80 and 82.

A frame. or yoke indicated generally by the ntuneral 84. acts as the supporting agency for the bearings 80 and '82, this yoke comprising

end plates

86 and 88 having secured thereto by means of screw S90 a first side plate 92 and a second side plate 94. As will presently be better understood hereinafter, the heads 48 and are to remain electrically isolated from each other and withthis aim in mind it will be observed that theside plate 94 is of insulating material. Provision is made for the conduction of electric current from the head 50 via the stub shaft 78 by means of a terminal strip 96having sufficient resiliency so as to bear against the projecting end of said shaft 78. A screw 98 serves to clamp the bared end of a conductor 100 to the terminal strip 96. Shownonly schematically is a ground connection 102 leading to the other stub shaft 76. More will besaidpresently concerning the circuitry of which the conductor 100 and ground 102 are components.

By reason of apertures 104 in the end plates 86- and 88 of the yoke 84, the pickup assemblage, of which. the drum 44 is a part, is constrained for vertical movement in the direction of the strip 12. Biasing a'ctionv for this constrained movement is: furnished by a pairof coil springs 196 compressed slightly between the. nuts 42and the lower edgesof the endplates 86', 88 (Figure 3). It

is important, however, that upward movement of the drum 44' be limited so that the upper face of the base plate 22 is substantially tangent to the drums periphery, and to this end a pair of sleeves 108 is employed, these sleeves encircling the upper portions of the guides 40. Since over a period of time some wear of the drum 44 is to be expected, it will be appreciated that these sleeves 108 may be shortened to compensate for such wear, the shortened sleeves permitting. the axis of rotation to be raised.

As already brought out, the subject matter of this invention will find utility in machines for cutting pictures from paper strips of indeterminate length. Cooperating in the realization of this desideratum is a plurality of electrically conductive lines or marks, such as the penciled or graphite line 110 appearing in Figure 2. These lines 110 are applied prior to the feeding of the strip across the table 10 and are spaced so that the individual prints will have uniform ma-rginsthereon when severed from the strip".

Owing to the employment of a number of discs or annularplates 54, 56', any adjacent pair of which will complete a circuit tothe appurtenant braking and cutting apparatus, it will be appreciated that these pairs combine in action toredtrcethe contact resistance between a particular line 110 and the diso's 54, 56, thus enabling the pickup to function with only-the passage of a small quantity of current between pairs of discs. Stated somewhat difierently, the" invention envisages a plurality of parallel electrical paths, permitting the use of a relatively low voltage applied to the conductive lines 110,- yet assuring'th'e' supply of adequate current tothe control system by minimizing any potential drop viathe successive conductive" lines 1 10. It" will of course be understood that the length -of the'conductive lines 110maybe' made commensurate with the overall length of the stacked drum 44 as determinedby the number of discs used in the drums construction. i

The operation of the cutting machine exemplified in Figure 1 is very simple: The pre marked strip 12 is fed in the direction indicated" byt-he .arrow 112 of Figure 2. When the mark 110' reachesthe drum 44, the mark or line 110, through the medium of its electrically conductivecharacteristics, bridges at least one pair of

discs

54, 56; Inasmuch asthese-various discs orannular plates aremaintainedwat a preferred potential difference by a suitable powersource in" circuit with the conductors and 102 and the control system for the solenoid actuated brake 14 and cutter1'6, the-feeding of the strip 12' is'momentarily arrested while the cutter blade descends against the. strip to sever off the leading'print. It might be explainedin more detail that the control current in coursingthrough the drum 44 passes through the terminal strip 96, the stub shaft 78 th'e head 50, the studs 64 to the various discs 54. Bri'dgedby a line or mark the current continues-its flow via the discs 56, the sleeve 52 and head 48, thestub shaft 76 to ground at 102.

After a cutting operation the circuit is opened (as by opening normally closed'contacts by a projection carried by the cutting tool apparatus) with the result that the-brake releases its' pressure'upon the strip 12 so that 'it is permitted to proceed once again until another line 110 comes intooperative juxtaposition with the drum 44, thereby repeating the foregoing action in a cyclic fashion.

As many changes could be made in the above construction and many apparently widely different embodiments ofthe." invention could be made without departing from: the scope thereof, it isintended that all matter contained in thelabovedescription or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also; to be understood that the language used in the followin'g'c'l-aimss is intended to cover all of the generic and. specific features of the invention herein" described and all statements of the scope of the invention which, as a matter of Language, might me said to fall therebetween.

What is claimed:

1. In a strip cutting machine, a rotatable drum including a pair of metallic drum heads, one of which has an integral sleeve thereon, a first group of closely spaced annular metallic plates circumscribed about said sleeve, a second group of annular metallic plates spacedly circumscribed about said sleeve in alternate fashion with respect to the plates of said first group, insulating washers interposed between adjacent plates of said alternate first and second groups, both of said groups having aligned eccentrically located apertures, stud means extending through said aligned apertures, the apertures of said first group of plates being substantially commensurate in size with said stud means to provide contact therebetween, and the apertures of said second plate group being larger than said stud means, said one head having aperture means accommodating one end of said stud means with sufficient clearance to provide electrical insulation therebetween and the other head having aperture means of such size as to engage the other end of said stud means, whereby said first group of plates is electrically connected to said one head and said second group is electrically connected to said second head.

2. Electrical pick up apparatus comprising: a generally cylindrical drum rotatable about its longitudinal axis; a pair of electrically conductive stub shafts, one projecting concentrically from each end of said drum and together constituting a rotational support therefor; means electrically insulating the stub shafts from each other; two series of closely spaced electrically conductive annular plates carried on said drum, the plates of one series being respectively positioned between respective adjacent plates of the other series, and the peripheral edges of all plates in both series together constituting the peripheral surface of the drum; means electrically insulating the plates of one series from the plates of the other series; means electrically connecting all the plates of one series to one of said stub shafts; and means electrically connecting all the plates of the other series to the other of said stub shafts, whereby an electrical bridging between a plate of one series and a plate of the other series electrically connects said shafts.

3. The apparatus described in claim 2 and separate electrical connections to said shafts for maintaining them at different electrical potentials.

4. The apparatus described in claim 2 and a frame for supporting the drum for rotation on said shafts.

5. Electrical pick up apparatus comprising: a generally spool shaped drum including a pair of electrically conductive enlarged diameter ends one of which is electrically separated from the other; a pair of electrically conductive stub shafts, one projecting concentrically from each enlarged diameter drum end, each shaft being in electrical contact with one drum end, the two shafts together constituting an axis of rotation for the drum; a number one and a number two series of electrically conductive closely spaced annular plates carried on said drum between said heads, the plate of the number one series being respectively positioned between the plates of the number two series, and the peripheral edges of all said plates together constituting the peripheral surface of the drum; means electrically insulating the plates of one series from the plates of the other series; means electrically connecting all the plates of the number one series with one enlarged diameter drum end and consequently with its shaft; means electrically connecting all plates of the number two series with the other one of the enlargeddrum ends and its shaft; and separate electrical connections to the shafts for maintaining them and their respective series of plates at different electrical potentials.

6. Electrical pick up apparatus comprising: a generally spool shaped drum of electrically conductive material, one enlarged diameter head of which is electrically insulated from the cylindrical portion and the other enlarged diameter head thereof; a pair of electrically conductive stub shafts, one projecting concentrically outward from and in electrical contact with each head, and together constituting a rotational axis for said drum; a number one and a number two series of closely spaced electrically conductive annular plates on the cylindrical portion of said drum, the plates of one series being in electrical contact with the cylindrical portion of the drum and being respectively positioned between the plates of the other series; electrical insulation between adjacent plates; and means electrically connecting the plates of said other series to said one enlarged diameter head of the drum, whereby one shaft through its respective head is electrically connected to the plates of only one of the two series of plates, and the other shaft through its head is electrically connected only to the plates of the other of the two series and an electrical bridging of any two adjacent plates electrically connects said shafts.

7. The apparatus described in claim 6 and separate electrical connections to said shafts for maintaining them at different electrical potentials.

8. The apparatus described in claim 6 and a frame supporting said shafts to permit drum rotation.

9. Electrical pick up apparatus comprising: a generally spool shaped drum including an electrically conductive enlarged diameter main head integrally carried on one end of a reduced diameter cylindrical portion, and a like diameter electrically conductive sub-head arranged adjacent but spaced from the other end of said cylindrical portion to prevent direct electrical conduction between the two heads; electrically conductive coaxial shafts, one projecting concentrically outward from each head, and together constituting a rotational axis for the drum; a number one and a number two series of closely spaced electrically conductive annular plates on the reduced diameter cylindrical portion of said drum between said heads, the plates of the number one series being respec tively positioned between the plates of the number two series, the outside diameters of all said plates being identical and at least as great as the diameters of said enlarged heads, said heads and all said plates being concentric with respect to the drum rotational axis; electrical insulating washers between adjacent ones of all said plates, the interior diameters of one series of said plates being such that the plates of said one series fit tightly on and are in direct electrical contact with the said cylindrical portion of the drum and consequently with its integral head and its shaft, the interior diameters of the other series of plates being larger than the exterior diameter of said cylindrical portion, and the other series plates therefore not being in electrical contact with said cylindrical portion; electrically conductive stay bolts extending through all said plates, insulating washers and. the sub-head but in electrical contact only with said other series of plates and said sub-head; whereby one shaft, through its head, is in circuit with one series of said plates and the other shaft, through its head, is in circuit with the other series of said plates, and an electrical bridging of any two adjacent plates electrically connects said shafts.

Germany Aug. 28, 1943