US 3854643 A
Apparatus including a tape drive capstan and a cooperating movable pressure roller where a slight movement of the pressure roller due to a splice passing between the capstan and pressure roller produces a signal which causes retraction of the pressure roller from an operative position.
Description (OCR text may contain errors)
United States Patent 1191 Weaver Dec. 117, 1974 SPLICE FINDER  References Cited  Inventor: Preston R. Weaver, Rocky Hill, UNITED STATES PATENTS Con". 3,561,700 2/1971 Adams et al 226/35 3,643,846 2/l972 Kato ct al. 226/l55  Ass'gnee' UMC Electmmcs Company North 3,718,269 2/1973 Glaettli 226/35 Haven, Conn.
l Filed? 1973 Primary Examiner-Allen N. Knowles  1 Appl NU; 415,650 Attorney, Agent, or Firm-DeLio and Montgomery Related U.S. Application Data 57 ABSTRACT  Continuation-impart of Ser. No. 339,704, March 9, 1 v
1973, abandoned. Apparatus including a tape drive capstan and a cooperating movable-pressure roller where a slight move-  U.S. Cl 226/35, 226/45, 226/154, ment of the pressure roller due to a splice passing be- 226/176 tween the capstan and pressure roller produces a sig- [51 Int. Cl B65h 23/16 nal which causes retraction of the pressure roller from  Field of Search 226/176, 177, 45, 35, 90, an operative position.
13 Claims, 11 Drawing Figures SHEET 3 0F 4 PATENTEL EEC 1 7 m4 PAIENIEB 3.854.643
, sum 11 0F SPLICE FINDER This application is a continuation-in-part of copending application Ser. No. 339,704 filed Mar. 9, 1973, now abandoned.
This invention relates to apparatusfor detecting a change in width of strip material passing between two rolling members.
In many applications, material in strip form may be spliced together from various pieces to achieve the overall length desired. In some applications the length of tape may be formed in a continuous roll requiring a splice at the ends thereof. Additionally, lengths of tape which contain audio or video intelligence may be spliced as to content of various sections into a continuous length. Moreover, in some quality control operations it may be necessary to determine when the thickness of material in strip or tape form is over a predetermined amount.
The present invention provides an apparatus in which changes in the thickness of strip material such as a thin tape passing between a'pair of rolling members may be readily and easily determined.
A particular application for the present invention, and the environment in which'it will be disclosed, is for locating splices on audio and video recording tape. A great majority of broadcast studios utilize pre-recorded announcements on tapes. The tapes are generally in a cartridge which are stored for easy retrieval and reused as necessary. These tapes bearing the recorded announcements, in most applications, are spliced and have two ends joined so as to form an endless loop and are arranged on a reel in a cartridge. Prior .to the present invention, to locate the splice on such a tape, a constant frequency signal is generally recorded on the tape and then the tape is played to detect an interruption in the constant frequency signal which signifies the ends of the tape and, hence, the splice. These cartridges are from time to time erased and new program material or announcements recorded thereon. Prior to recording new program material or announcements, it is necessary to locate the splice and commence the recording just subsequent to the splice so that the announcement is not recorded over the splice.
The present practice in recording new material is to erase the recording on the tape through the use of a bulk type eraser, record the constant frequency signal, usually three kilohertz, on the tape, detect the splice electronically, erase the constant frequency signal by means of a bulk eraser and then record the new announcement. It will be readily apparent that this is a rather time-consuming technique.
Accordingly, the present invention provides a new and improved device for locating a splice or other overthickness portion on the tape very quickly.
Briefly stated, the invention in one form thereof comprises cooperating roller members, one of which is driven and drives the tape when both rollers are in contact therewith. One of the rollers is carried on a shaft which is movable between an operative position and a retracted position. When a very slight movement of the movable roller occurs, such movement is sensed and the means holding it in driving contact with the tape is deactivated. The splice or over-thickness area of the tape is then definitely located.
An object of this invention is to provide a new and improved apparatus for locating a splice or other over or under thickness point in a length of strip material or tape.
. Another object of this invention is to provide apparatus for locating a splice or point in a length of tape or strip material and immediately deactivating a drive means for such tape.
Another object of. this invention is to provide a new and improved means for moving a pressure wheel away from a driving capstan when a tape splice passes therebetween.
A further object of this invention is to provide new and improved apparatus for locating a tape splice and erasing material on the tape in a minimum of time.
The features of the invention which are believed to be novel are particularly pointed out and distinctly claimed in the concluding portion of this specification. However, the invention both as to its organization and operation, together with further objects and advantages thereof, may best be appreciated by reference to the following detailed description taken in conjunction with the drawing, wherein:
FIG. 1 is a plan view of a device embodying the invention;
FIG. 2 is an enlarged view of the device of FIG. 1 with the top wall partially cut away;
FIG. 3 is a side elevation of the device of FIG. 1 with the sidewall removed;
FIG. 4 is a drawing representative of a tape cartridge utilized in conjunction with the invention;
FIG. 5 is a view of a tape splice showing splicing tape on both sides of a tape joint;
FIG. 6 is a schematic diagram of a control circuit that may be used in conjunction with the invention;
FIG. 7 is a top plan view of a tape drive with the top housing member partially cut away to illustrate the drive system thereof;
FIG. 8 is a view seen in the plane oflines 8.8 of FIG.
FIG. 9 is a view seen in the plane of lines 9-9 of FIG. 7;
FIG. 10 is a top plan view of an alternate embodiment of that shown in FIGS. 7 9; and
FIG. 11 is a view seen in the plane of lines 11-11 of FIG. 10. I 7
An embodiment of the invention adapted to operate on a tape cartridge for pre-recorded broadcast messages is disclosed and reference is first made to the cartridge 10 of FIG. 4. This cartridge comprises a reel 11 having thereon an endless length of tape 12 disposed about guides 13 and l4.An aperture 15 is defined in the bottom of the cartridge to permit entrance of a pressure roller, as hereinafter described. The reel 11 includes a disc 16 which is normally engaged by a brake member 17 carried on a resilient arm 18 anchored at 19. The cartridge is recessed as indicated at 20 to permit the tape 12 to engage drive capstan. The brake is released by the shaft of a pressure wheel engaging portion 21 of the arm 18. Arm l8 and a portion 21 are disposed below the level of the tape 12.
When the cartridge is placed on the splice finder it is moved to a position where the pressure wheel pivots upwardly through aperture 15 and the shaft thereof pushes outwardly on portion 21 to release the brake as the pressure roller engaged one side of the tape and forces and holds the tape into driving engagement with a capstan.
A splice finding device, as shown in FIGS. 1 3, comprises a housing 25 having a top wall or surface 26, and opposed pairs of vertical side walls 27 and 28. Pivotally mounted below surface 26 is a pivotal shaft 29 which carries thereon a shaft 30 about which pressure roller 31 is rotatable.
Also carried by shaft 29 is an arm 32 (FIG. 3). When shaft 29 is rotated approximately 90, arm 32 will engage a sensing device which comprises a magnetic core or armature 33 within a coil 34. Arm 32 when moved to the position in dotted line will also close a switch 35.
Shaft 29 is normally biased to the position shown in FIG. 3 by a spring 36 attached at one end to a bracket 37 on the underside of surface 26 and attached at the other end to a strip 38 which is secured to shaft 29 as by means of a screw 39. The spring 36 comprises a means for moving the pressure roller to a retract position. Strap 38 passes about shaft 29 and is attached to the plunger or armature 40 of a solenoid 41. Solenoid 41 provides a means for holding pressure roller 31 in an operative position. Solenoid 41 will include its own armature biasing spring (not shown) which will tend to extend armature 40 when the solenoid is not energized. Further carried on shaft 29 is an arm providing member 42 connected to a link 43 which is, in turn, connected at its other end to a lever 44 (FIG. 2). Lever 44 is pivotally mounted as indicated at 45 beneath the surface 26. The other end of lever 44 is pivotally mounted to a slide member 46. Slide member 46 is moved to the right as viewed in FIG. 2 when engaged by end surface a of cartridge 10. Such movement will pivot lever 44 about its pivot point 45 and cause pivotal movement of shaft 29. Slide 46 includes a depending end 49 adapted to operate a switch 50 when moved to a dotted line position as shown in FIG. 2. Slide 46 has an upstanding end portion 52 with an adjustable abutment 53 thereon which extends above surface 26 through aperture 54 therein.
The pressure roller 31, when pivoted to the position shown in broken line in FIG. 3 is adapted to produce pressure on tape 12 passing therebetween and a capstan 60. Capstan 60 is rotatably supported in a bracket member 61 depending from surface 26 and carries thereon a pulley 62 driven by a belt 63 from a motor 64 mounted to the underside of surface 26.
The operation of the device thus far described is now explained.
When it is desired to locate the splice on a tape 12 of a cartridge 10, the cartridge is moved into position as shown in FIG. 1, surface 20a thereof engages abut ment 53 on slide 46 pushing the slide 46 to the right as viewed in FIGS. 2 and 3 and at the same time rotating shaft 29 towards the position shown in broken line in FIG. 3. When portion 49 of slide 46 operates switch 50, solenoid 41 will be energized to hold shaft 29 and pressure roller 31 in the position shown in broken line in FIG. 3. The solenoid will be energized when the pressure roller is about one eighth inch or less from the capstan. As arm 32 is rotated to the broken line position of FIG. 3, it will move the armature 33 inwardly of coil 34 of the sensing device, and close a switch 35 which will initiate a time delay for reasons hereinafter ex plained.
Also included in the device supported beneath surface 26 is a bulk erase coil 65. A pressure switch 71 which extends upwardly through surface 26 senses the existence of a cartridge 10 on surface 26, applies power to motor 64 to condition the unit for operation.
Reference is now made to FIG. 6 which shows a schematic diagram of the controls. The energization of the erase coil 65 is controlled by a switch 66 located on surface 26 which may be briefly depressed to energize coil 65.
The control includes a power transformer 75, a full wave rectifier 76. A predetermined voltage is applied to coil 34 of the sensor from a pair of zener diodes 77 and the other side of the coilis connected to an amplifier 78. Any slight movement of the armature 33 within coil 34 will create a voltage pulse which is applied to amplifier 78 and hence, to a threshold detecting amplifier 79. When the pulse applied to amplifier 79 reaches a predetermined value as determined by potentiometer 80, amplifier 79 will turn on a transistor 81 to apply a gating signal over line 82 to a controlled rectifier (CR) 83. Upon firing of CR 83 a relay 84 is energized when a contact 85a of a relay 85 is closed. When energized, relay 84 will open a normally closed contact 84a which is in series with solenoid 41 and switch 50.
When the cartridge is inserted and pivots pressure roller 31 toward the position'shown in broken line in FIG. 3, switch 50 is closed and solenoid 41 is energized over line 86 through switch 50, contact 84a and line 87 to hold pressure roller 31 in an operative position.
When arm 32 actuates switch 35, it removes the ground from a timing capacitor 88 and capacitor 88 will charge over line 89 and through resistance 90. After a predetermined time delay as determined by resistance 90 and capacitance 88,the voltage buildup on capacitor 88 will turn on a uni-junction transistor 91 which will gate a controlled rectifier 92. When this occurs, relay 85 is energized and closes its contacts 85a, 85b and 85c. Capacitor 88 will discharge through contact 85c, contact 85a in closing completes a circuit to CR 83 through relay 84. Relay 85 is latched in through contact 85b and switch 35 while the anode of CR 91 is grounded and extinguished. The purpose of the time delay is to compensate for any transients in the circuit at start-up so that no undesired triggering action of the controlled rectifiers might occur.
At this time the pressure roller 31 engages capstan 60 and the tape 12 will be driven. When a spliced point in the tape indicated at S (FIG. 5) with splicing material S1 and/or S2 passes between pressure roller 31 and capstan 60, there will be a very slight movement of pressure roller 31 and shaft 29. This movement imparts a slight movement to shaft 29 and, hence, arm 32.
When arm 32 moves, armature 33 moves with respect to coil 34 and a voltage pulse is induced therein. The pulse is applied to amplifier 78 and the amplified pulse is then applied to peak detecting amplifier 79. Transistor 81 turns on and gates CR 83, and relay 84 is energized. When relay 84 is energized contact 84a is dropped out opening the circuit to solenoid 41, spring 36 immediately retracts pressure roller 31 as brake 17 engages disc 16 on reel 11 and the tape is stopped at the splice.
The cartridge 10 may now be removed and either erased on the bulk eraser comprising coil 65 by momentarily depressing switch 66, or the tape may be stored for later recording. At this time, the splice position is known so that if the tape is to be used again it is positioned for the start of the new recorded announcement or program material without the possibility of recording over the splice. Alternatively, the tape may be stored for later recording.
The splice shown in FIG. 5 utilizes two pieces of splicing tape S1 and S2. However, it will be understood that in most splices only one of the splicing tapes S1 or S2 is utilized. The splicing tape is generally of the same thickness as the recordingtape and while this is only on the order of 0.001 inch such small movement that the increased thickness imparts to the pressure roller is sufficient to create the voltage change in coil 33 and trigger a control circuit as described in FIG. 6.
The splice finding locating device as disclosed operates on a complete cycle merely by the positioning of a cartridge thereon. However, if desired the operation may be made more manual as, for example, permitting manual operation of the switches and manual operation of the motor.
In FIG. 6, the control circuit has been shown in schematic form and conventional practices such as protective resistors, diodes, etc., about the relay coils and controlled rectifiers have not been specifically identified inasmuch as such identification is not necessary to an understanding of the invention.
The invention may also be utilized in apparatus where the strip material to be monitored is on open reels, or not in loop form.
FIGS. 7 9 exemplify the invention as applied to tape on open reels. A housing 93 includes an upper deck member 94. Extending above deck member 94 are spindles 95 and 96 upon which reels 97 and 98 are disposed, respectively. As shown, tape is paid-off from reel 98 and taken up on reel 97. From reel 98, the tape 99 passes partially about a tension roller 100 which includes a pivotal arm 101 biased by a spring 102 to maintain tension in the tape. Thereafter, the tape passes through a first pair of guide rollers 103 to a capstan 104 and pressure wheel 105 to a second pair of guide rollers 106 and, hence, to reel 97. A motor 110 drives the capstan, and also through conventional transmission (not shown) drives the shafts 95 and 96 upon which reels 97 and 98, respectively, are positioned. Motor 110 drives a capstan 104 through a motor pulley 111, a capstan pulley 112 and a belt 113. Capstan 104 is rotatably mounted in a slide member 114. Slide 114 is slidable in guides 115 and 116 carried on the underside of member 94 toward and away from pressure wheel 105 between an operating position and a retract position. Slide 114 is attached to the midportion of a leaf spring 1 17 which has its outer extremities attached to a lever 118. At least one end of spring 117 has a slot therein through which the attaching screw passes to permit flexing of the spring. Lever 118 is pivoted at one end thereof to a member 120 supported from the underside of member 94. The other end of lever 118 is pivotally connected to the plunger 121a of a solenoid 121. Connected between lever 118 and a fixed point 122 on member 94 is a return or retract spring 123. Spring 123 is a means for retracting slide 114. This function may also be served by the provision of a return spring on the plunger 121a of solenoid 121. Pivotally mounted to an extension 124 of slide 114 is a lever 125 whose other end bears on the moving core or armature 126 of a sensor 127. Lever 125 is pivoted intermediate the ends thereof at 128 to a member 129 supported from member 94. This defines lever arms 125a and 125b.
In this embodiment the driving capstan 104 is movable between an operating position and a retract position.
In operation, to drive tape 99 solenoid 121 is energized which pivots lever 118 counterclockwise, as shown in FIG. 7, causing lever 118 through spring 117 to move slide 114 and capstan 104 into driving engagement with tape 99 and pressure roller 105. If a splice or section of predetermined different thickness of the tape passes between pressure roller 105 and capstan 101, a small movement to the right (as viewed in FIG. 7) is imparted to slide 114. Such movement produces a very small pivotal motion of lever 1250 about pivot point 128. Arm 125b of lever 125 amplifies this motion and moves against member 126, and a signal is generated by sensor 127. In response to this generated signal solenoid 121 is de-energized, spring 123 pivots lever 118 clockwise (as viewed in FIG. 7) and withdraws capstan 101 from driving engagement with tape 99.
The circuitry disclosed in FIG. 6 may be used for the control of the mechanism of FIG. 7.
FIG. 10 shows an alternate embodiment of the invention in a top plan view where the motor 110 drives a pulley 129 disposed on the shaft of pressure roller 105.
In this embodiment the movable member, or capstan in response to movement of the tape driving member.
It will be apparent that the apparatus may be utilized to determine and locate either a predetermined overthickness or under-thickness of strip material. If the material is under a predetermined thickness, the solenoid will pull further in on the lever attached to the movable roller, and the sensor will generate a pulse.
The sensor may be any type of transducer which will generate the necessary signal in response to a mechanical movement.
It may thus be seen that the objects of the invention set forth as well as those made apparent from the foregoing description are efficiently attained. While preferred embodiments of the invention have been set forth for purposes of disclosure, modification to the disclosed embodiments of the invention as well as other embodiments thereof may occur to those skilled in the art. Accordingly, the appended claims are intended to cover all embodiments of the invention and modifications to the disclosed embodiments which do not depart from the spirit-and scope of the invention.
What is claimed is:
1. Apparatus for detecting a splice in a length of recording tape where two ends of tape are spanned by a splicing tape, comprising a capstan for driving the tape, a pressure wheel adapted to contact the tape on one side thereof and hold said tape against the capstan, said pressure wheel being carried on a movable shaft, means for moving said shaft toward a retract position away from said capstan, means for holding said shaft in an operating position in which the pressure wheel engages the tape, and sensing means responsive to movement of said shaft when a splice on said tape passes between said capstan and said pressure roller for deactivating said holding means whereby said moving means moves said shaft towards a retract position.
2. The apparatus of claim 1 wherein said shaft is pivotally mounted, said means for moving is a spring which is tensioned upon movement of said pressure wheel to engage the tape, and said holding means is a solenoid acting in opposition to said spring when energized, and means responsive to said pressure roller moving to engage the tape for energizing said solenoid.
3. The apparatus of claim 1 further including a member arranged for pivotal motion, said pressure wheel shaft extending from said member.
4. The apparatus of claim 2 further including an arm member extending from said pivotal member, a sensing device positioned to be contacted by said arm member as said pressure wheel is moved into contact with said tape, said holding means acting on said pivotal member, said sensing means being effective to emit a signal indicative of movement of said arm member and means responsive to the signal for deactivating said holding means.
5. The apparatus of claim 1 wherein said holding means is a solenoid, means for energizing said solenoid as the pressure wheel engages the tape, said means responsive to movement of said shaft comprising a transducer adapted to emit a signal upon movement of said shaft, and means responsive to the transducer signal for de-energizing the solenoid.
6. The apparatus of claim 5 wherein said pivotallymounted shaft extends from a pivot providing means, an arm extending from said pivot providing means, said transducer sensing movement of said arm.
7. The apparatus of claim 6 wherein said transducer is a coil receiving a core therein and said arm contacts said core when said pressure roller engages said tape.
8. Apparatus for detecting a splice in a length of recording tape in a cartridge where two ends of tape are spanned by a splicing tape, comprising a capstan for driving the tape, and means for driving the capstan, a
pressure wheel adapted to contact the tape on one side thereof and hold said tape against the capstan, said pressure wheel being carried'on a movable shaft, means for moving said shaft toward a retract position away from said capstan, means for holding said shaft in an operating position in which the pressure wheel engages thetape, means responsive to positioning of the cartridge on said apparatus for engaging tape with said capstan for moving said shaft toward a tape engaging position and means for energizing said holding means as said pressure roller engages the tape, and means responsive to movement of said shaft when a splice on said tape passes between said capstan and said pressure roller for deactivating said holding means whereby said means for moving moves said shaft towards a retract position.
9. Apparatus for detecting a predetermined change in thickness in a length of strip material, comprising first and second rollers defining a path therebetween for the strip material, a movable member carrying said first roller, first means for moving said member toward said second roller to engage the strip between said rollers and hold said first roller into a strip engaging position, second means for moving said member toward a retract position away from said second roller, and sensing means responsive to movement of said shaft in response to a predetermined change in dimension of the strip passing between said rollers for deactivating said first means for moving whereby said second means for 12. The apparatus of claim 9 wherein one of said rollers is a capstan and the other is a pressure roller.
13. The apparatus of claim 9 wherein the strip material is a recording tape and the points of change in thickness sought to be located are splices.