GB2205987A

GB2205987A - Automatic reversing tape recorder

Info

Publication number: GB2205987A
Application number: GB08811786A
Authority: GB
Inventors: Toshio Yoshimura
Original assignee: Tanashin Denki Co Ltd
Current assignee: Tanashin Denki Co Ltd
Priority date: 1987-05-20
Filing date: 1988-05-18
Publication date: 1988-12-21
Anticipated expiration: 2008-05-18
Also published as: GB8811786D0; GB2205987B

Abstract

On reversal a pinch roller changeover mechanism, coupled by arm 39 through resilient pins 61a, 61b, drives a slider 36 which through gears 33, 32, rotates the head 14 mounted in the cylindrical rotary member 15. The arm 39 overdrives to leave spring pressure to hold the head firmly in its limit positions. In place of flexible fingers 61a, 61b, spring pressure at the limit positions may come from an over-dead-centre spring (44) between the slider and the gear 33. Head rotation is limited by tab 16 engaging stops 26a, 26b , which are bifurcations at the ends of a wave-shaped spring plate 23, the adjacent limbs of the bifurcations being flexibly secured by adjusting screws. The head is rotated while still in contact with the tape. Changeover is governed by a trip gear (56) rotating in 180 degree steps. <IMAGE>

Description

AUTOMATIC REVERSING TAPE RECORDER BACKGROUND OF THE INVENTION 1) Field of the Invention This invention relates to an automatic reversing tape recorder of the type wherein a 2-track head is turned over each time the feeding direction of a tape is reversed.

2) DescrA#tAon of the Prick Art A head of a tape recorder is normally made of permalloy, ferrite or a like material and is one of considerably expensive components in a tape recorder mechanism. Particularly, a 4-track head which is conventionally employed in automatic reversing tape recorders is far more expensive than a 2-track head.

Some of recent automatic reversing tape recorders, therefore, employ a less expensive 2-track head in order to contemplate reduction in cost thereof. The head is turned over an angle of 180 degrees around an axis perpendicular to a tape contacting face thereof each time the feeding direction of a magnetic tape is reversed.

An exemplary one of such automatic reversing tape recorders is illustrated in FIG. 7.

Referring to FIG. 7, the tape recorder shown includes a 2-track head 1 which will be hereinafter referred to only as head. The head 1 is securely mounted at a forward end of a rotary member 2 which is in turn supported on a head base 3 for rotation around an axis perpendicular to a tape contacting face of the head 1 for contacting with a magnetic tape. The rotary member 2 is turned over an angle of 180 degrees in an alternate direction around the axis by a head driving mechanism not shown.

An abutting member 4 like a blade or wing is securely mounted on and extends radially outwardly from an outer periphery of the rotary member 2. A pair of azimuth adjusting screws 5a and 5b are screwed in the head base 3 such that lower ends thereof may extend into a range of turning movement of the abutting member 4 of the rotary member 2. As the rotary member 2 rotates around the axis thereof, the abutting member 2 will be engaged with the end of one of the azimuth adjusting screws 5a and 5b and thus stopped from further rotation by the latter. The range of rotation of the rotary member 2 is thus controlled to 180 degrees by the azimuth adjusting screws 5a and 5b.A pair of compression coil springs 6a and 6b are interposed between the head base 3 and the heads of the azimuth adjusting screws 5a and 5b in order to prevent unintended eventual loosening of the azimuth adjusting screws 5a and 5b with upward biasing forces of the compression coil springs 6a and 6b, respectively.

Though not shown, a pair of capstans and a pair of corresponding pinch rollers are mounted at locations on a chassis of the automatic reversing tape recorder on the left and right sides of the head base 3.

With the automatic reversing tape recorder having such a construction as described above, when it is in a reproducing or recording mode, one of the pinch rollers on the tape winding wide is held in contact with the corresponding capstan while the other pinch roller is held out of contact with the corresponding capstan. In this instance, the abutting member 4 is held in contact with the lower end of the azimuth adjusting screw Sa, for example, at a location A of FIG. 7.

When the tape then comes to its end, this is detected by a tape end detecting mechanism not shown, and in response to a mechanical tape end detection signal from the tape end detecting mechanism, the one pinch roller is moved away from the capstan and the other pinch roller is moved into contact with the capstan instead. Such change-over of contacting relationship of the pinch rollers with the capstans is effected by a pinch roller changing over mechanism not shown. The head driving mechanism operates in association with the operation of the pinch roller changing over mechanism.Upon operation of the head driving mechanism, the rotary member 2 is rotated an angle of 180 degrees around the axis thereof perpendicular to a tape contacting face of the head 1 until the abutting member 4 of the rotary member 2 is now engaged with and stopped by the end of the other azimuth adjusting screw 5b as at another location B shown in FIG. 7.

With the tape recorder, intended azimuth adjustment can be attained by suitably loosening or tightening the left and/or right azimuth adjusting screws Sa and/or 5b to change the contacting positions of the ends of the azimuth adjusting screws 5a and/or 5b with the abutting member 4 of the rotary member 2.

In such a conventional automatic reversing tape recorder as described above, the head base 3 is retracted once from its operative position to move the head 1 out of a cassette when the feeding direction of the tape is reversed, and then the head 1 is turned over an angle of 180 degrees around its axis whereafter the head base 3 is advanced again to its operative position to move the head 1 into contact with the tape within the cassette.

A mechanism for advancing or retracting the head base 3 each time the feeding direction of a tape is reversed is thus required, and accordingly, there is a problem that the tape recorder requires an increased number of parts for the mechanism. It is another problem that it is necessary to adjust an operation timing of the mechanism relative to operating timings of the head driving mechanism and the pinch roller changing over mechanism and consequently the tape recorder is complicated in construction.

The inventors of the present patent application have proceeded and are proceeding development of an automatic reversing tape recorder of such a construction that the head 1 is turned over within a cassette while the head 1 is held in contact with a face of the tape.

If the head is turned over within a cassette in this manner, this will eliminate the necessity of the mechanism for causing advancing and retracting movement of the head base 3 each time the feeding direction of a tape is reversed as in a conventional tape recorder.

The tape recorder is simplified in construction accordingly.

In order to further simplify the construction, it may be recommended to drive the pinch roller changing over mechanism and the head driving mechanism using a common driving source. Common use of a single driving source, however, involves a following problem. In particular, if the head driving mechanism and the pinch roller driving mechanism are connected directly to each other in order to drive the two mechanisms from the common driving source, the head driving mechanism will have a fixed range of motion because the pinch roller changing over mechanism has a fixed range of motion.

This will disable azimuth adjustment of the head.

SUMMARY OF THE~INVENTION It is an object of the present invention to provide an automatic reversing tape recorder which can be simplified in construction while enabling azimuth adjustment.

In order to attain the object, according to the present invention, there is provided an automatic reversing tape recorder which includes a pinch roller changing over mechanism for reversing the feeding direction of a tape, a head driving mechanism including a head driving member which moves in one or the other direction between a pair of opposite end positions in response to operation of the pinch roller changing over mechanism, and an azimuth adjusting mechanism for making azimuth adjustment of a 2-track head, and wherein, each time a tape is fed to an end thereof, the head driving mechanism is moved forwardly or reversely to turn over the 2-track head an angle of 180 degrees around an axis thereof perpendicular to a ta#pe contacting face thereof without moving the 2-track head away from the tape, characterized in that one of operating parts of the pinch roller changing over mechanism is provided for engagement with the head driving member while a resilient member is provided for holding the head driving member at an alternative one of the end positions thereof, whereby, when the pinch roller changing over mechanism reverses the feeding direction of the tape, the head driving member is moved from one to the other of the end positions or alternatively from the other to the one end position in response to the movement of the pinch roller changing over mechanism, whereafter the head driving member is held at the other or the one end position under the biasing force of the resilient member.

With the automatic reversing tape recorder, the driving source for the pinch roller changing over mechanism can be used also as a driving source for the head driving mechanism. Besides, azimuth adjustment of the head is enabled because the excessive amount of movement of the one operating part of the pinch roller changing over mechanism is absorbed by the resilient member.

According to the present invention, therefore, an automatic reversing tape recorder can be provided which is simplified in construction and reduced in size while enabling azimuth adjustment of a magnetic head.

A specific embodiment of the present invention will now be described in detail by way of example with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWTNGS FIG. 1 is a partial plan view of an automatic reversing tape recorder showing a preferred embodiment of the present invention; FIG. 2 is a fragmentary perspective view of a head mounting structure of the tape recorder of FIG. 1; FIG. 3 is a vertical sectional view showing an azimuth adjusting mechanism of the tape recorder of FIG. 1; FIG.- 4 is a perspective view showing a head driving mechanism of the tape recorder of FIG. 1; FIG. 5 is a perspective view of a head driving mechanism of another automatic reversing tape recorder showing a second preferred embodiment of the present invention; FIG. 6 is an enlarged vertical sectional view showing engaging portions of a head driving member and a pivotal changing over plate of the head driving mechanism of FIG. 5; and FIG. 7 is a partial front elevational view of an azimuth adjusting mechanism of a conventional automatic reversing tape recorder.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT Referring first to FIGS. 1 to 4, there is shown an automatic reversing tape recorder of a preferred embodiment of the present invention. The automatic reversing tape recorder shown includes a head driving mechanism 11, an azimuth adjusting mechanism 12, a pinch roller changing over mechanism 13, and a 2-track magnetic head 14. The head 14 has a sufficiently small size to allow the same to rotate within a tape cassette not shown and is secured to a forward end of a rotary member 15 as seen in FIG. 2. An abutting member 16 like a blade or wing is securely mounted on and extends outwardly in a radial direction from an outer periphery of the rotary member 15. The rotary member 15 has a reduced diameter portion 17 adjacent a rear end thereof remote from the head 14.The rotary member 15 is mounted on a head base 18 made of a synthetic resin for rotation around an axis C perpendicular to a tape contacting face of the head 14 at which the head 14 is to contact with a magnetic tape not shown of the tape cassette. The head base 18 is secured to an upper face of a head mounting plate 19 by means of screws not shown. The head mounting plate 19 is formed from a metal plate and is mounted for back and forth movement on a chassis not shown of the. tape recorder. The head base 18 has a generally box-like configuration and has an accommodating section 20 in which the rotary member 15 is accommodated. The accommodating section 20 of the head base 18 includes a front wall in which a large diameter hole 21 is perforated, and a rear wall in which a small diameter hole 22 is perforated.In assembling the rotary member 15 to the head base 18, the rotary member 15 is inserted from the small diameter portion 17 side thereof into the large diameter hole 21 in the front wall of the accommodating section 20 of the head base 18 with the abutting member 16 thereof directed in a horizontal direction, and then the small diameter portion 17 is fitted into the small diameter hole 22 in the rear wall of the accommodating section 20 until it is projected outwardly from the rear wall. The head driving mechanism 11 is connected to the projected portion of the small diameter portion 17 of the rotary member 15.

The azimuth adjusting mechanism 12 is provided in the accommodating section 20 of the head base 18. The azimuth adjusting mechanism 12 includes a stopper member 23 made of a single spring plate having a Substantially U-shape in front elevation and disposed in the accommodating section 20 as shown in FIGS. 2 and 3. The stopper member 23 is branched or bifurcated at the opposite end portions of the U-shape thereof defining a pair of azimuth adjusting portions 25a and 25b and a pair of stopper portions 26a and 26b. A pair of screw insertion holes 24a and 24b are perforated in the azimuth adjusting portions 25a and 25b, respectively, of the stopper member 23. The left and right stopper portions 26a and 26b of the stopper member 23 are positioned within a range of rotation of the abutting member 16 of the rotary member 15 so that, when the rotary member 15 is rotated in a direction, the abutting member 16 may be contacted with and stopped by either one of the stoppers 26a and 26b in order to define the range of rotation of the rotary member 15.

A pair of azimuth adjusting screws 27a and 27b extend through the screw inserting holes 24a and 24b of the stopper member 23 as particularly seen in FIG. 3, and threaded end portions of the screws 27a and 27b are individually screwed in threaded holes 28a and 28b formed in the head mounting plate 19. The azimuth adjusting screws 27a and 27b are thus normally biased upwardly by the azimuth adjusting portions 25a and#25b, respectively, of the stopper member 23 so that unintended eventual loosening thereof is prevented by the resilient biasing force of the stopper member 23.A positioning square hole 29 is perforated in a central bottom portion of the stopper member 23, and a projection 30 in the form of a square post provided on an upper face of the head base 18 is fitted in the angular hole 29 in order to position the stopper member 23 relative to the head base 18 and prevent pivotal motion of the stopper member 23 relative to the head base 18. In order to thus make azimuth adjustment of the head 14, the left and/or right azimuth adjusting screws 27a and/or 27b are suitably loosened or tightened to displace the stopper portions 26a and 26b of the stopper member 23 in a vertical direction. Particularly in the case of the tape recorder of the present embodiment, accurate azimuth adjustment can be attained readily.This is because the amount of displacement of the azimuth adjusting portions 25a and 25b of the stopper member 23 is smaller than the amount of displacement of the stopper portions 26a and 26b due to the fact that the stopper portions 26a and 26b are located at inner positions with respect to the threaded holes 28a and 28b of the head mounting plate 19 in which the azimuth adjusting screws 27a and 27b are screwed for adjustment.

The head driving mechanism 11 includes a gear 32 securely mounted at the rearwardly projected end of the small diameter portion 17 of the rotary member 15. A compression coil spring 31 is interposed between the gear 32 and the rear wall of the accommodating section 20 of the head base 18 as seen in FIG. 2. The head driving mechanism 11 further includes a multiple gear member 33 having a sector gear 34 for selectively engaging with the gear 32 and a pinion 35 provided for coaxial and integral rotation with the sector gear 34.

The pinion 35 is held in normal meshing engagement with a rack 37 of a head driving member 36 which is also one of components of the head driving mechanism 11. The head driving member 36 has, formed at a longitudinal end thereof, a bent inverted T-shaped engaging piece 38 which extends substantially in parallel to the axis of rotation of the rotary member 15 as seen in FIG. 4.

A pivotal changing over plate 39 which is one of components of the pinch roller changing over mechanism 13 is associated with the head driving member 36. The pivotal changing over plate 39 is mounted for pivotal motion in a coaxial relationship with a right-hand side capstan 40a as seen in FIG. 1. The pivotal changing over plate 39 has a pair of laterally bent lugs 41a and 41b formed at an end portion of an arm thereof, and the engaging piece 38-of the head driving member 36 is located between the laterally bent lugs 41a of the pivotal changing over plate 39.The laterally bent lugs 41a and 41b are spaced from each other by a sufficiently greater distance than the thickness of material of the engaging piece 38 of the head driving member 38 so that when the pivotal changing over plate 39 is pivoted, one of the bent pieces 41a and 41b thereon may selectively press against the engaging piece 38 to move the head driving member 36 in a direction perpendicular to the forward and rearward direction of the head mounting plate 19 without a trouble. Upon such movement of the head driving member 36, the multiple gear member 33 is rotated by the rack 37 of the head driving member 36, and the gear 32 is rotated by the multiple gear member 33 so that the rotary member 15 is turned over an angle of 180 degrees.

A turn-over spring 44 in the form of a torsion spring is mounted at an intermediate portion thereof on the head base 18 and extends between a guide member 42 secured to the head base 18 and a spring receiving pin 43 secured to an eccentric location of the multiple gear member 33. The turn-over spring 44 thus serves as a resilient member for biasing the head driving member 36 and the multiple gear member 33 to move away from each other. As the multiple gear member 33 is biased by the turn-over spring 44, the rotary member 15 is biased by way of the gear 32 such that when the abutting member 16 thereof contacts with the left stopper portion 26a of the stopper member 23, it is resiliently pressed against the latter, but when it contacts with the right stopper portion 26b, it is resiliently pressed against the right stopper portion 26b.Accordingly, the head 14 is held with certainty at an alternative one of a pair of fixed positions whether the abutting member 16 of the rotary member 15 is held in contact with the stopper portion 26a or 26b of the stopper member 23 under the biasing force of the turn-over spring 44.

A pair of pinch levers 45a and 45b are mounted for pivotal motion around a pair of shafts 46a and 46b, respectively, mounted on the chassis of the tape recorder. A pair of pinch rollers 47a and 47b for alternately contacting with the left and right capstans 40a and 40b, respectively, are supported for rotation at pivoting end portions of the pinch levers 45a and 45b, respectively. When the tape recorder is in the reproducing or recording mode, either one of the pinch rollers 47a and 47b is pressed against the corresponding capstan 40a or 40b, and when the pinch roller changing over mechanism 13 is rendered operative, the left and right pinch rollers 47a and 47b are alternately contacted with and spaced away from the corresponding capstans 40a and 40b, respectively.

The pinch roller changing over mechanism 13 includes, in addition to the pivotal changing over plate 39, a slide plate 49 mounted for leftward and rightward sliding movement on the tape recorder chassis. The slide plate 49 has an elongated hole 50 formed therein through which a pin 48 secured to the pivotal changing over plate 39 extends. The slide plate 49 further has a cam hole 51 formed therein in which a cam pin 53 is fitted. The cam pin 53 is secured to a pinch roller changing over plate 52 which is mounted for pivotal motion around a shaft 54 on the head mounting plate 19.

A wire spring 55 is mounted at a location on the pinch roller changing over plate 52 near a central portion of pivotal motion of the latter and extends in the leftward and rightward directions from the location. The opposite end portions of the wire spring 55 normally engage with the pivoting ends of the pinch levers 45a and 4dub. When the pinch roller changing over plate 52 is pivoted, one of the pinch rollers 47a and 47b is brought into contact with the capstan 40a or 40b. The pinch roller changing over mechanism 13 further includes a change-over gear 56 having a pin 57 securely provided on an upper face thereof. The pin 57 is fitted in an elongated hole 58 formed in the pivotal changing over plate 39.The change-over gear 56 has a pair of no tooth portions 56a and 56b at diametrically symmetrical locations thereof and is positioned for selective meshing engagement with a constantly rotating drive gear 59 of a smaller diameter. The change-over lever 56 is normally biased to rotate in the counterclockwise direction in FIG. 1 by the resilient force of the wire spring 55 which is transmitted thereto via the pinch roller changing over plate 52, slide plate 49 and pivotal changing over plate 39.

Though not shown, a trigger mechanism is provided for arresting the drive gear 56 to prevent the changeover gear 56 from being meshed with the drive gear 59 during feeding of a tape. When the tape comes to its end, the trigger mechanism operates in response to a tape end detection signal and cancels the arrested condition of the change-over gear 56 to allow the change-over gear 56 to be meshed with the drive gear 59 by the biasing force of the wire spring 55. Then, when the change-over lever 56 is rotated an angle of 180 degrees by the drive gear 59 to a position in which the other no tooth portion 56a or 56b opposes the drive gear 59, rotation of the change-over gear 56 is inhibited again by the trigger mechanism. During such rotation of the change-over gear 56, the pivotal changing over plate 39 is pivoted by the change-over gear 56.Upon such pivotal motion of the pivotal changing over plate 39, the slide plate 49 and hence the pinch roller changing over plate 52 are operated by the same, and as the change-over plate 52 thus operates, the left and right pinch rollers 47a and 47b are alternatively contacted with and spaced away from the corresponding pinch rollers 40a and 40b, respectively. At the same time, the head driving member 36, multiple gear member 33 and gear 32 are moved successively by the pivotal changing over plate 39 thereby to turn over the head 14 an angle of 180 degrees around the axis thereof.

Operation of the automatic reversing tape recorder will be described subsequently.

In a condition of the tape recorder wherein the right-hand side pinch roller 47a is held in contact with the corresponding capstan 40a as shown in FIG. 1 so that a magnetic tape not shown is fed in the rightward direction in FIG. 1, the abutting member 16 of the rotary member 15 is held in contact at a location A in FIG. 3 with the stopper portion 26a of the stopper member 23 as indicated in phantom in FIG. 3.

When the tape comes to its end, the trigger mechanism operates in response to such a tape end detection signal so that the change-over gear 56 is brought into meshing engagement with the drive gear 59.

The change-over gear 56 is consequently rotated an angle of 180 degrees in the counterclockwise direction in FIG. 1. Upon such rotation of the change-over gear 56, the right-hand side pinch roller 47a is moved away from the corresponding capstan 40a while at the same time the left-hand side pinch roller 47b is pressed against the corresponding capstan 40b. Meanwhile, as the pivotal changing over plate 39 is pivoted, the rotary member 15 is turned over so that the head 14 is turned over an angle of 180 degrees around the axis thereof while remaining in contact with a face of the tape and the abutting member 16 of the rotary member 15 is now brought into contact with and stopped by the other stopper portion 26b of the stopper member 23 as at a location B in FIG. 3.The impact upon the stopper portion 26b of the stopper member 23 when the abutting member 16 is brought into contact with the stopper portion 26b is absorbed by the resilient stopper portion 26b itself of the stopper member 23 and hence will not be imparted to the azimuth adjusting screw 27b. There is no possibility, accordingly, that the azimuth adjusting screw 27b may be loosened by the impact.

It is to be noted that when the pivotal changing over plate 39 is pivoted, the head driving member 36 is moved in the following manners. In particular, at first the head driving member 36 is moved in the leftward or rightward direction in FIG. 1 or 4 to a neutral position of the turn-over spring 44 by the operating force of the pinch roller changing over mechanism 13. Then, after the head driving member 36 moves farther than the neutral position of the turn-over spring 44, it is moved in the same direction now by the biasing force of the turn-over spring 44 which is transmitted thereto via the multiple gear member 33 and the rack 37 on the head driving member 36.In this instance, before the head driving member 36 reaches its end position, the engagement between the pivotal changing over plate 39 of the pinch roller changing over mechanism 13 and the head driving member 36 is rendered ineffective.

With the embodiment described above, the pivotal changing over plate 39 which is one of operating parts of the pinch roller changing over mechanism 13 is directly coupled to the head driving member 36.

Accordingly, there is no necessity of provision of a separate mechanism for operating the head driving member 36, and hence reduction in number of parts and simplification of construction of the tape recorder can be attained. Further, since the head 14 is held with certainty at a fixed position by the turn-over spring 44 as a resilient member, stabilization of the frequency characteristic can also be anticipated.

Subsequently, a second embodiment of the present invention will be described with reference to FIGS. 5 and 6. The automatic reversing tape recorder of the second embodiment has a generally similar construction to that of the first embodiment. Therefore, like parts or elements are denoted by like reference numerals to those of the first embodiment of FIGS. 1 to 4, and overlapping description thereof is omitted herein.

A pivotal changing over plate 39 which is one of operating parts of a pinch roller changing over mechanism 13 has a pair of wire springs 61a and 61b mounted in a spaced relationship at an end portion thereof. The wire springs 61a and 61b serve as resilient members and extend upwardly in parallel to each other. The wire springs 61a and 61b may be formed as a single spring member which is bent substantially in a U-shape as seen in FIG. 6. The spring member is assembled to the pivotal changing over plate 39 with a central bottom portion of the U-shape thereof engaged with an engaging lug 62 provided on the pivotal changing over plate 39 and with the opposite arms thereof fitted in an opening 63 formed in the pivotal changing over plate 39 as shown in FIG. 6.The opposite arms of the spring member, that is, the wire springs 61a and 61b, are thus projected upwardly from the end portion of the pivotal changing over plate 39. An engaging piece 38 of a head driving member 36 is located between the wire springs 61a and 61b on the pivotal changing over plate 39.

If the pivotal changing over plate 39 is pivoted so that the engaging piece 38 of the head driving member 36 is pressed by either one of the wire springs 61a and 61b on the pivotal changing over plate 39, the head driving member 36 is moved so that a rotary member 15 is rotated via a multiple gear member 33 and a gear 32 to turn over a head 14 by an angle of 180 degrees around an axis thereof.

Here, the amount of pivotal motion of the pivotal changing over plate 39 when the feeding direction of a tape is reversed remains constant, and the head driving member 26 reaches an end position of movement thereof while the pivotal changing over plate 39 is still being pivoted. The excessive amount of movement of the pivotal changing over plate 39 after it reaches its end position is absorbed by the wire spring 61a or 61b.

Accordingly, azimuth adjustment of the head is possible independently of the pivotal changing over plate 39, and there is no possibility that the pivotal motion of the pivotal changing over plate 39 may be hindered.

With the automatic reversing tape recorder of the second embodiment described above, since the change-over operating plate 39 which is one of operating parts of the pinch roller changing over mechanism 13 is coupled to the head driving member 36 by way of the wire springs 61a and 61b, there is no necessity of provision of a separate mechanism for operating the head driving member 36, and reduction in number of parts can be anticipated and construction can be simplified.

Besides, since the wire springs 61a and 61b are resiliently deformed after the head driving member 36 has reached the end position of movement thereof, the head 14 is held in position with certainty so that stabilization of the frequency characteristic can be anticipated and there is no possibility that operation of the pinch roller changing over mechanism 13 may be prevented.

While the present invention has been described so far in connection with the preferred embodiments thereof, it is to be noted that the present invention is not limited to the specific embodiments described above and various modifications and alterations may be made to the embodiments without departing from a scope and a spirit of the present invention. For example, a leaf spring or a spring of some other type may be employed as a resilient member in place of the wire spring. Or, the resilient member may be provided on the head driving member 36 side. Or else, a resilient member may be located between a pair of rigid abutting members.

Claims

CLAIMS:

1. An automatic reversing tape recorder which includes a pinch roller changing over mechanism for reversing the feeding direction of a tape, a head driving mechanism including a head driving member which moves in one or the other direction between a pair of opposite end positions in response to operation of said pinch roller changing over mechanism, and an azimuth adjusting mechanism for making azimuth adjustment of a 2-track head, and wherein, each time a tape is fed to an end thereof, said head driving mechanism is moved forwardly or reversely to turn over said 2-track head an angle of 180 degrees around an axis thereof perpendicular to a tape contacting face thereof without moving said 2-track head away from the tape, characterized in that one of operating parts of said pinch roller changing over mechanism is provided for engagement with said head driving member while a resilient member is provided for holding said head driving member at an alternative one of the end positions thereof, whereby, when said pinch roller changing over mechanism reverses the feeding direction of the tape, said head driving member is moved from one to the other of the end positions or alternatively from the other to the one end position in response to the movement of said pinch roller changing over mechanism, whereafter said head driving member is held at the other or the one end position under the biasing force of said resilient member.

2. An automatic reversing tape recorder as set forth in claim 1, characterized in that said resilient member is a turn-over spring which acts, after said head driving member is moved in the one or the other direction farther than a neutral position of said turnover spring by the operating force of said pinch roller changing over mechanism, to resiliently move said head driving member in the same direction to the other or the one end position, and before said head driving member reaches the other or the one end position, the engagement between the one operating part of said pinch roller changing over mechanism and said head driving member is rendered ineffective.

3. An automatic reversing tape recorder as set forth in claim 2, characterized in that said pinch roller changing over mechanism includes a rotary member which rotates an angle of 180 degrees alternatively in one or the other direction around an axis in response to a tape end detection signal; a pivotal changing over plate which pivots alternatively in one or the other direction around one of a pair of capstans in response to rotation of said rotary member, a slide plate which moves alternatively in one or the other direction in response to operation of said pivotal changing over plate, and a pinch roller changing over plate responsive to operation of said slide plate for alternatively moving a pair of left and right pinch rollers into or out of engagement with the corresponding capstans, said pivotal changing over plate having thereon a portion located for engagement with said head driving member.

4. An automatic reversing tape recorder as set forth in claim 1, characterized in that said resilient member is interposed between and couples the one operating part of said pinch roller changing over mechanism and said head driving member to each other such that said resilient member moves said head driving member to the one or the other end position while the one operating part is still moving.

5. An automatic reversing tape recorder as set forth in claim 4, characterized in that said pinch roller changing over mechanism includes a rotary member which rotates an angle of 180 degrees alternatively in one or the other direction around an axis in response to a tape end detection signal, a pivotal changing over plate which pivots alternatively in one or the other direction around one of a pair of capstans in response to rotation of said rotary member, a slide plate which moves alternatively in one or the other direction in response to operation of said pivotal changing over plate, and a pinch roller changing over plate responsive to operation of said slide plate for alternatively moving a pair of left and right pinch rollers into or out of engagement with the corresponding capstans, said pivotal changing over plate having thereon a portion located for engagement with said head driving member.

6. An automatic reversing tape recorder as set forth in claim 4 or 5, characterized in that said resilient member is a wire spring.

7. An automatic reversing tape recorder substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.