US2553392A - Recording head feeding device - Google Patents

Description

May 15, 1951 F. VAN EPS 2,553,392

RECORDING HEAD FEEDING DEVICE Filed Jan. 31, 1945 2 Sheets-Sheet l INVENTOR 1W4 Van 0S ORNEY May 15, 1951 F. VAN EPS. 2,553,392

RECORDING HEAD FEEDING DEVICE Filed Jan. 51, 1945 2 Sheets-Sheet 2 I lifii lllllll a I W j ENTOR v I Ikea Van/E 05 19 10 EQ QW TTORNEY Patented May 15, 1951 UNITED STATES PATENT OFFICE RECORDING HEAD FEEDING DEVICE Fred Van Eps, Plainfield, N. J.

Application January 31, 1945, Serial No. 575,398

Claims.

This invention relates to sound recording apparatus and the like of the type having a cutting head moving across the record blank as it is rotated and more particularly to improved means for driving the feed screw for the cutting head.

In the production of disc sound records by the type of apparatus to which the invention applies, the record groove is formed on the disc blank as a succession of convolutions by the cutting head moving across the blank as the latter is rotated by the supporting turn table. The cutting head is mounted in a carriage which is movably supported on a carrier. The carrier is provided with a feed screw which operatively engages the cutting head carriage to move it along its path.

It has been found desirable to have a sound recording machine in which the drive mechanism for the feed screw can quickly and easily be disengaged. It is also desirable to be able to quickly and easily disengage the cutting head from the record blank at any point of its travel to increase its life.

Modern conditions also demand that a sound recording apparatus include means for changing the regular rate of feed of the recording head across the disc record blank. An important, if not the principal, reason is to use the same machine for making records for different purposes, requiring difierent groove characteristics. So, for instance, ordinary commercial phonograph records are recorded at approximately '78 revolutions per minute and with 90 to 100 grooves per inch leaving a substantial wall between adjacent grooves, while records for electrical transcription purposes are usually recorded at 33 /3 revolutions per minute and are made with their sound grooves closer together.

Another object is to provide means for immediate and easy disengagement of the cutting head from the disc blank at any point of its travel across the blank.

It is therefore among the objects of the invention to provide an improved mechanism for driving the feed screw which can easily be adjusted with respect to the rate of speed.

A further object is to provide means for the aforesaid purposes which are simple and inexpensive in constructions and which can easily be attached to any turn table.

Other objects and advantages inherent in the invention will become apparent from the following specification taken in conjunction with the accompanying drawing and which discloses by way of example an embodiment of the inventive idea.

In the drawing:

Figure 1 is a plan view of a recording apparatus according to the invention having a portion cut away.

Figure 2 is a sectional view taken along the line 2--2 of Figure 1.

Figure 3 is a sectional view taken along the line 33 of Figure 1 showing the cutting head and its carriage.

Figure 4 is an end view partially in section showing the drive mechanism.

Figure 5 is a section taken along the line 55 of Figure 1.

Referring in greater detail to the accompanying drawing, the recording apparatus includes a turn table H] which may be driven by any mechanism usual in the art. The cutting head ll, equipped with a recording stylus i2, is supported by the carriage generally indicated at [3, and which is impelled across the record [4 by the feed screw l5 during the operation of the apparatus.

The feed screw [5 is rotatably mounted in the carrier generally indicated at It between the brackets i1 and 18. The bracket IT is spaced above the turntable It) and substantially opposite the center thereof by the arm 20, which is anchored to the base 19 at the side of the turntable so as to permit free rotation of the latter. Similarly, the bracket i8 is mounted to the base I9 by means of the foot 2!.

The carrier It is also provided with a base plate 22 which extends between the brackets IT and I8.

The cutting head carriage l3 comprises a top plate 23 which is slidably and rotatably mounted on the tie rod 24 by means of the sleeve 25. The tie rod 2 3 is in turn mounted in the brackets ll and I8.

The carriage I3 also comprises a face plate 26 to which are pivoted the bars 21. Between the bars 2'! are the spacers 23 and 29. A plate 33 is pivotally connected to the bars 21 between the outer ends thereof and is provided with a pair of grooves to which the cutting head ii is secured by means of screws 3!.

The pressure exerted by the recording stylus l2 upon the record blank i i may be controlled as desired by means of the spring 32 and the set screw 33 on the arm 35 extending from the face plate 26.

The weight of the cutting head also may be counterbalanced by the weight 35 which is connected to the lever arm 3% over the pulley 37.

The recording stylus i2 can easily be brought out of and into contact with the record by means of the cam lever 31 which is mounted on the face plate 26.

The means for actuating the feed screw to move the recording stylus across the record I4, comprise a gear wheel 38 which is operatively connected to the feed screw i5 by means of an over running clutch mechanism generally indicated at 39, and the worm 49 on the shaft 4! which at its other end is provided with a friction wheel 42. This friction wheel 42 functionally engages the friction disc '43 of the sleeve 44 which is mounted over the centering pin 45. The sleeve 44 is also provided with a driving flange 49 which engages the record so as to be rotated thereby. Alternatively, friction wheel 42 may directly engage the top of the record in which case the driving flange 46 and the friction disc 43 carried thereby may be dispensed with.

Describing the aforesaid means in greater detail, the gear wheel 38 together with the disc 41 are rotatably mounted on the stub shaft 48 of the feed screw I5. On this stub shaft 48 is also fixedly mounted the ratchet wheel 49 of the clutch mechanism as for example, by means of the screw '56. The clutch mechanism also includes the pawl 5! which is pivoted to the disc 41 normally urged into engagement with the ratchet wheel 49 by the spring 52. With the described construction it will be clear that as the worm gear 36 is rotated by the worm 49 it acts through the ratchet wheel 49 and pawl 5! to rotate the stub shaft 48 and the feed screw [5 at a fixed speed relative to the rate of rotation of the turntable [9, This relative rate of speed can be varied by moving the friction wheel 42 towards and away from the center of the friction disc 43. For this purpose the friction wheel is adjustably mounted on the shaft 4| by means of the set screws 53.

It will also be seen that by reason of the over running clutch mechanism the friction wheel 42 can easily be raised out of engagement with the friction disc 43 for the purpose of adjustment without the feed screw being rotated.

The shaft 41 is journalled in the bearing blocks 54 of the arm 55 which also is rotatably mounted on the stub shaft 48 together with the gear wheel 38.

The bearing blocks 54 may also serve as weights to hold the friction wheel 42 in engagement with the friction disc 43.

' As the feed screw is rotated it impels the carriage l3 along its path. To this end the car--. riage is provided with a thread engaging plate 56 which is carried by the bracket 57 and which is in turn mounted on the sleeve 25.

The apparatus disclosed also includes means for manually operating the feed screw I5v at a higher rate of speed then is possible with the regular driving means disclosed herein. To this end the shaft 57 of the feed screw is provided with a gear 58 which meshes with a larger gear 59. This latter gear 59 is mounted in the bearing block 66 on the bracket l8 and may be rotated by the crank 6|.

By virtue of the over running clutch mechanism previously described, it will be seen that by manual operation of the crank 6|, the feed screw 15 can be rotated at a speed greater than that normally imparted to it by the turn table drive so that the recording head can be moved across the record blank at a much higher than normal speed to provide a high pitch cross over groove from one recorded zone to the start of another or from a recorded zone to a terminal circle or the like.

The apparatus according to the invention also includes means for disengaging the thread plate 56 from the feed screw l5 at any point of its path. To this end a rectangular bar 62 is provided which is pivoted excentrically between the brackets l1 and I8. In other words, this bar constitutes a toggle mechanism for lowering and raising the carriage I 3. For this purpose, the carriage is provided with an adjustable set screw 63 having a head which normally engages the bar 62. When the stylus is in recording position on the disc blank the bar will be in the position shown in full lines in Figure 3. On the other hand, when the plate 56 is disengaged from the feed screw l5, the carriage will be in the position shown in dotted lines.

The bar 62 may be turned by the handle 65 against the'pressure of the spring urged plunger 66 which is mounted in the base plate 22.

The apparatus according to the invention also includes means for automatically disengaging the recording head from the record when the carrier comes to the end of its path. These means comprise an arm 6? which is fixed to the bar 2? at a predetermined angle and the bevelled member 63 mounted on the bracket H. The arm '67 and the member 68 are so relatively adjusted that the arm 6'! will engage the bevelled edge of the member 68 as soon as the carriage has come adjacent the end of its path. Further movement will then cause the recordinghead to rise out of engagement with the recording blank due to the pivotal mounting of the bars 21 and '28. The pivotal movement of the bars 27 and 26 may be limited by the stop 67 abutting against the plate 26.

It will be understood that this description has been given by way of example and not by way of limitation. On the other hand, the invention may lend itself to a variety of expressions within the scope of the appended claims.

What is claimed is:

1. A recording apparatus comprising a turntable for supporting a record during the recording operation, a record grooving device, a feed screw for moving said grooving device radially across the record as the latter is rotated, means for driving said feed screw, said means including a worm gear carried by said feed screw, a disc mounted centrally on said record, a shaft extending perpendicularly to said feed screw, a worm on said shaft meshing with said worm gear and a wheel on said shaft for frictionally engaging said disc, said shaft being rotatable about said feed screw in a vertical plane whereby said wheel may be disengaged from said disc.

2. A recording apparatus comprising a turntable for supporting a record during the recording operation, a record grooving device, a feed screw for moving said grooving device radially across the record as the latter is rotated, means for driving said feed screw, said means including a worm gear rotatably mounted on said feed screw, a clutch mechanism for connecting said worm gear operatively with said feed screw to rotate, with said feed screw in one direction, a shaft extending perpendicularly to said feed screw, a worm on said shaft meshing with said worm gear, a disc centrally mounted on said record, a wheel on said shaft for frictionally engaging said disc, and a lost motion device associated with said clutch mechanism whereby said wheel may be disengaged fromsaid disc.

3. A recording apparatus comprising a turntable for supporting a record during the recording operation, a record grooving device, a feed screw for moving said grooving device radially across the record as the latter is rotated, means for driving said feed screw, said means including a worm gear rotatably mounted on said feed screw, a clutch mechanism for connecting said worm gear operatively with said feed screw to rotate with said feed screw in one direction, a shaft extending perpendicularly to said feed screw, a worm on said shaft meshing with said Worm gear, a disc centrally mounted on said record, a wheel on said shaft for frictionally engaging said disc, a lost motion device assooiated with said clutch mechanism whereby said wheel may be disengaged from said disc, and means for raising said grooving device out of engagement with said record.

4. A recording apparatus comprising a turntable for supporting a record during the recording operation, a record grooving device, a feed screw for moving said grooving device radially across the record as the latter is rotated, said feed screw extending eccentrically of the record, means for driving said feed screw, said means including a worm gear rotatably mounted on said feed screw, a clutch mechanism for connecting said Worm gear operatively with said feed screw, a disc centrally mounted on said record, a shaft extending radially with respect to said record, a worm on said shaft meshing with said worm gear, a wheel on said shaft for frictionally engaging said disc, a st motion device associated with said clutch mechanism whereby said wheel may be dis-engaged from said disc and means for raising said grooving device out of engagement with said record.

5. A recording apparatus comprising a turntable for supporting a record during the recording operation, a record grooving device, a feed screw for moving said grooving device radially across the record as the latter is rotated, said feed screw extending eccentrically of the record, means for driving said feed screw at variable speeds, said means including a worm gear rotatably mounted on said feed screw, a clutch mech anism for connecting said worm gear operatively with said feed screw, a disc centrally mounted on said record, a shaft extending radially with respect to said record, a worm on said shaft meshing with said worm gear, a wheel adjustably mounted on said shaft for frictionally engaging said disc, a lost motion device associated with said clutch mechanism whereby said wheel may be disengaged from said disc.

FRED VAN EPS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,027,350 Mikorey May 21, 1912 1,399,239 Ahearn Dec. 6, 1921 2,340,658 Goldman Feb. 1, 1944 2,350,490 Berliner June 6, 1944 FOREIGN PATENTS Number Country Date 436,157 France Mar. 20, 1912 270,085 Germany Feb. 6, 1914 359,532 Great Britain Oct. 22, 1931 370,418 Great Britain Apr. 4, 1932

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