US3585895A - Player piano tracking system - Google Patents

Abstract

A tracking system for a player piano including a pair of pressure-sensitive switches provided at opposite ends of the tracker bar and connected by an electrical circuit to a reversible drive motor which realigns the sheet material by laterally adjusting the roll carrier.

Description

United States Patent Richard L. Cannon; 7

[award R. D. Smith, both of Yankton, S. M.

June 13, 1969 June 22, 1971 Dale Electronics, Inc.

Columbus, Nebr.

Inventors Appl. No. Filed Patented Assignee PLAYER PIANO TRACKING SYSTEM 5 Claims, 5 Drawing Flp.

U.S.Cl 84/137, 84/139 Int. Cl (11015/06 Field of Search; 84/122,

123,136,137,140,l4l;226/l0,15, 19

[56] References Cited UNITED STATES PATENTS 789,053 5/1905 O'Connor 84/136 (UX) 1,163,274 12/1915 Southgate 84/ l 38 3,444,770 5/1969 Cannon et al 84/139 Primary ExaminerRichard B. Wilkinson Assistant Examiner-.lohn F. Gonzales AuorneyZarley. McKee & Thomte ABSTRACT: A tracking system for a player piano including a pair of pressure-sensitive switches provided at opposite ends of the tracker bar and connected by an electrical circuit to a reversible drive. motor which realigns the sheet material by laterally adjusting the roll carrier.

PLAYER PIANO-TRACKING SYSTEM The piano rolls commonly used on player pianos have an irregular width and thus the music rolls have a tendency not to roll in alignment even when the carrier and takeup rolls are axially aligned. Moisture in the atmosphere also will cause the paper to expand thereby providing irregularities in the width of the music roll.Another problem is that the spools sometimes are not in complete alignment.

U.S. Pat. No. 3,444,770 discloses a tracking system designed to overcome the problems listed above and was generally satisfactory in operation. However, the system disclosed herein is an improvement over the device described in said patent since the need for a full wave bridge rectifier and tracking relay is eliminated which results in a system which is more economical to manufacture and which is more reliable in operation.

Therefore, it is a principal object of this invention to provide a tracking system for player pianos that will continuously adjust the music roll to compensate for any irregularities in width or lateral movements of the roll as it is being operated.

Another object of this invention is to provide a tracking system for player pianos which will accommodate rolls of varying widths and includes a tracking sensing means positioned at both sides of the music roll.

Yet another object of this invention is to provide a tracking system for player pianos including means to deactivate the tracking gear motor when the tracking ports on opposite sides of the sheet member are both exposed.

A further object of this invention is to provide a tracking system for 'player pianos which is reliable in operation.

A further object of this invention is to provide a tracking system for player. pianos which is economical of manufacture, and durable in use.

These and other objects will be apparent to those skilled in the art.

This invention consists in the construction, arrangements, and combination of the various parts of the device, whereby the objects contemplated are attained as hereinafter more fully set forth, specifically pointed out in the claims, and illustrated in the accompanying drawings in which F IG. 1 is a fragmentary perspective view of the system of this invention;

FIG. 2 is a side elevational view as seen along lines 2-2 of FIG. 1;

FIG. 3 is a schematic view of the wiring diagram of this system;

FIG. 4 is a side elevational view of one form of the means for activating the pressure sensitive switches; and

FIG. 5 is a side elevational view of another form of the means for activating the pressure sensitive switches.

As illustrated in the drawings, the tracking system of this invention is employed on a player piano. The player piano includes a roll carrier or rewind roll having music roll sheet material 12 wound therearound and connected to a takeup roll 14. As seen in FIG. 1, the music roll extends over a tracker bar 16 positioned between the roll carrier 10 and takeup roll 14. It should be noted that only a portion of the tracker bar 16 is shown but it should be understood that the tracker bar means 16 is in communication with a source of vacuum pressure so that the ports 18 therein will sense the perforations in the sheet material. Tracker bar 16 is provided with tracking ports for passageways 20 and 22 adjacent its opposite sides which are positioned adjacent the opposite sides 24 and 26 respectively of the sheet material. Conduits 28 and 30 are in communication with ports 20 and 22 respectively and have bellows elements 32 and 34 connected to their lower ends thereof respectively. The bellows elements are normally com pressed when the player piano is operating to create a vacuum for the tracker bar means and will expand when air enters the port associated therewith. The bellows elements may be substituted by capsule elements such as element 33 of FIG. 5. Capsule element 33 is slidably mounted on the conduit and slidably moves downwardly thereon to the position of FIG. 5 when air enters the port associated therewith. v

The numeral 36 generally designates a switch means positioned below the bellows element 32 and including contacts 38 and 40. A switch means 42 is positioned below the bellows element 34 and includes contacts 44 and 46. The expansion of the bellows elements closes the switch means associated therewith as will be explained hereinafter. A lead 48 connects contact 44 with a terminal 50 of a reversible drive gear motor 52 having a rotatable power shaft 54' extending therefrom. Contact 46 of switch means 42 is connected to a suitable source of power 56 by a lead 58 and power source 56 is connected to terminal 60 of motor 52 by a lead 62. Contact 38 of switch means 36 is connected to terminal 64 of motor 52 by a lead 66. Contact 40 of switch means 36 is connected to lead 58 by a lead 68. Terminals 64 and 50 of motor 52 are connected to opposite ends of the coils within the motor 52 while terminal 60 is electrically connected to both of the coils as illustrated in the drawings.

A support frame (not shown) on the player piano is provided and slidably receives a longitudinal shaft 70 extending from the roll carrier 10. A cam wheel 72 is mounted on the shaft 70 and is yieldably urged outwardly from the roll carrier 10 by a spring means 74.A rewind motor (not shown) is provided and has a shaft (not shown) which is telescopically connected to the outer end of the shaft 70. A cam arm is' secured to the outer end of power shaft 54 and includes arm portions 82 and 84 through which shaft 70 extends. The rotation of the power shaft 54 in one direction causes the arm portions 82 and 84 to rotate into engagement with the cam wheel 72 to urge the shaft 70 to the left as viewed in the drawings. The rotation of the shaft 54 in an opposite direction causes the arm portions 82 and 84 to rotate away from the cam wheel 72 to permit the spring means 74 to urge the shaft 70 to the right as viewed in FIG. 1. In operation, it is seen that as the music roll 12 is fed across the tracker bar 16, the roll carrier shaft 74 is being normally urged to the right as viewed in FIG. 1; The arm portions 82 and 84 of'the cam arm 80 limits the movement of the shaft 70 to the right. When the sheet material covers both of the ports 20 and 22 during the playing operation, switches 42 and 36 will be open which results in the motor 52 being deactivated. When port 20 is exposed to the atmosphere, as would happen when the right edge of the sheet material moves to the left as viewed in FIG. 1, the bellows element 32 on the conduit 28 would expand to close the switch means 36 which would cause the motor 52 to be activated to rotate the power shaft 54 so that the arm portions 82 and 84 would move out of engagement with the cam wheel 72 to permit the spring means 74 to urge the shaft 70 to the right as viewed in FIG. 1 until the port 20 was again covered by the sheet material. As soon as the port 20 is covered by the sheet material, the bellows element 32 will contract to open the switch means 36 and deactivate the motor 52. The switch means 42 will function in the same manner as the switch means 36 upon port 22 being exposed to the atmosphere. When switch means 42 is closed by the bellows element 34, power shaft 54 will be rotated so that the arm portions 82 and 84 of cam arm 80 will engage cam wheel 72 and move the shaft 70 to the left as viewed in FIG. 1.

If both of the ports 20 and 22 are exposed to the atmosphere at the same time, motor saturation will occur and the shaft 54 will not be rotated until either of the ports become covered so as to allow the opposite port to either release the motor from saturation or dictate its movement in the proper direction. While the switches 36 and 42 have been primarily described as being opened and closed by a bellows element, it should be noted that the switches could be opened and closed by any suitable pressure sensitive means which would close the switches upon atmosphere being drawn into either of the ports 20 or 22 such as the capsules '33. The motor 52 permits the constant tracking of the music roll and such tracking is permitted by the switches 32 and 34 positioned below the sensing ports 20 and 22 respectively. It can be appreciated that the tracking system described herein is extremely efitcient in operation and ,will be economical of manufacture. The tracking system accurately senses irregularities in the width of the sheet material and laterally adjusts or realigns the roll carrier shaft to compensate for the variations in sheet width to permit the player piano to properly sense the perforations in the sheet material so that the proper notes are played in the correct manner. Thus it can be seen that the system accomplishes at least all of its stated objectives.

Some changes may be made in the construction and arrangement of our PLAYER PIANO TRACKING SYSTEM without departing from the real spirit and purpose of our invention, and it is our intention to cover by our claims, any modified forms of structure or use of mechanical equivalents which may be reasonably included within their scope.

We claim:

1. A tracking system for player pianos, comprising,

a roll carrier,

sheet material wound on said roll carrier,

a sheet material takeup means for receiving said sheet material from said roll carrier, 7

power means for moving said sheet material from said roll carrier to said takeup means, a tracker bar means positioned between said roll carrier and said takeup means, said sheet material passing thereover,

first and second spaced-apart passageways formed in said tracker bar means at opposite ends thereof adjacent the side edges of said sheet material,

first and second pressure sensitive switches connected to said first and second passageways respectively,

tracking adjusting means operatively connected to said first and second switches to control the lateral movement of said sheet material moving between said roll carrier and said takeup means,

said tracking adjusting means including a reversible drive motor operatively connected to said roll carrier to provide lateral movement of said roll carrier in response to actuation of one of said switches,

said switches being activated upon the passageways connected thereto being exposed to the atmosphere,

said switches being deactivated when said sheet material seals said passageways from the atmosphere.

2. The system of claim 1 wherein said roll carrier includes a driven shaft, a cam wheel mounted on said driven shaft, said motor including a power shaft having a cam arm mounted thereon adapted to engage said cam wheel and move said driven shaft in one lateral direction when said motor is rotated in one direction, a resilient means engaging said driven shaft normally urging said driven shaft in a lateral direction opposite to said one lateral direction whereby said driven shaft will be laterally moved in said opposite direction when said motor is rotated in a direction opposite to said one direction.

3. The system of claim 2 wherein said first switch includes first and second contacts, said second switch including first and second contacts, said motor including first, second and third terminals, a first lead connecting said first contact of said first switch to said third terminal, a second lead connecting said first contact of said second switch with said first terminal, a third lead connecting said second contact of said first switch to a power source, a fourth lead connecting said power source to said second terminal, and a fifth lead connecting said second contact of said second switch to said third lead.

4. The system of claim 1 wherein each of said passageways have a conduit extending therefrom, each of said conduits having a bellows mounted thereon, said bellows being adapted to expand and close the switch means associated therewith when its respective passageway is exposed to the atmosphere as said sheet material is passing over said tracker bar means.

5. The system of claim 4 wherein said motor will be deactivated when both of said switches are closed.

Claims (5)

1. A tracking system for player pianos, comprising, a roll carrier, sheet material wound on said roll carrier, a sheet material takeup means for receiving said sheet material from said roll carrier, power means for moving said sheet material from said roll carrier to said takeup means, a tracker bar means positioned between said roll carrier and said takeup means, said sheet material passing thereover, first and second spaced-apart passageways formed in said tracker bar means at opposite ends thereof adjacent the side edges of said sheet material, first and second pressure sensitive switches connected to said first and second passageways respectively, tracking adjusting means operatively connected to said first and second switches to control the lateral movement of said sheet material moving between said roll carrier and said takeup means, said tracking adjusting means including a reversible drive motor operatively connected to said roll carrier to provide lateral movement of said roll carrier in response to actuation of one of said switches, said switches being activated upon the passageways connected thereto being exposed to the atmosphere, said switches being deactivated when said sheet material seals said passageways from the atmosphere.

2. The system of claim 1 wherein said roll carrier includes a driven shaft, a cam wheel mounted on said driven shaft, said motor including a power shaft having a cam arm mounted thereon adapted to engage said cam wheel and move said driven shaft in one lateral direction when said motor is rotated in one direction, a resilient means engaging said driven shaft normally urging said driven shaft in a lateral direction opposite to said one lateral direction whereby said driven shaft will be laterally moved in said opposite direction when said motor is rotated in a direction opposite to said one direction.

3. The system of claim 2 wherein said first switch includes first and second contacts, said second switch iNcluding first and second contacts, said motor including first, second and third terminals, a first lead connecting said first contact of said first switch to said third terminal, a second lead connecting said first contact of said second switch with said first terminal, a third lead connecting said second contact of said first switch to a power source, a fourth lead connecting said power source to said second terminal, and a fifth lead connecting said second contact of said second switch to said third lead.

4. The system of claim 1 wherein each of said passageways have a conduit extending therefrom, each of said conduits having a bellows mounted thereon, said bellows being adapted to expand and close the switch means associated therewith when its respective passageway is exposed to the atmosphere as said sheet material is passing over said tracker bar means.

5. The system of claim 4 wherein said motor will be deactivated when both of said switches are closed.

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