US3651899A - Brake device in tape recorder - Google Patents

Brake device in tape recorder Download PDF

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Publication number
US3651899A
US3651899A US24219A US3651899DA US3651899A US 3651899 A US3651899 A US 3651899A US 24219 A US24219 A US 24219A US 3651899D A US3651899D A US 3651899DA US 3651899 A US3651899 A US 3651899A
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US
United States
Prior art keywords
lever
brake band
brake
spring
brake device
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US24219A
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English (en)
Inventor
Tetsuji Yoshii
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Application granted granted Critical
Publication of US3651899A publication Critical patent/US3651899A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B15/00—Driving, starting or stopping record carriers of filamentary or web form; Driving both such record carriers and heads; Guiding such record carriers or containers therefor; Control thereof; Control of operating function
    • G11B15/18—Driving; Starting; Stopping; Arrangements for control or regulation thereof
    • G11B15/22—Stopping means

Definitions

  • ABSTRACT A brake device in a tape recorder which includes a brake band entrained on a braked drum for movement in the direction of the braked drum, whereby one end portion of the brake band engages stop means in accordance with the direction of rotation of the braked drum to thereby provide a slack end portion of the brake band, while the other end portion of the brake band provides a tight portion to which is imparted a spring force having a predetermined characteristic.
  • This invention relates to a brake device used with the reel bed or the like in a tape recorder.
  • a different braking force (or different directivity of the braking force) is required in accordance with the direction of rotation of the reel bed.
  • the suitable directivity ratio for the braking force is 2 l in accordance counter-clockwise the variation in the amount of the tape wound on the reels, and it is required that a pair 'of such reel beds be arranged symmetrically to each other so as to ensure the smooth rotation thereof without causing the tape to be slack or broken in use.
  • the braking operation has usually been mostly accomplished by the press contact of a friction shoe with the braked drum of the reel bed.
  • FIG. 1 For example of the prior art brake device is shown in FIG. 1.
  • a brake band 15 has one end thereof connected to a spring 17 through a lever 16 and the other end connected to a pivotally mounted shaft 18.
  • the braking torque provided by a such brake device for the counterclockwise rotation of the reel bed 1 is expressed by the following equation:
  • MBN/MBRZBLH T represents the tension in the tight end portion of the brake band during the counter-clockwise rotation of the reel bed
  • T the tension in the slack end portion of the brake band during the clockwise rotation of the reel bed
  • T the tension, in the slack end portion of the brake band during the clockwise rotation of the reel bed
  • the angle of contact of the brake band with the braked drum (FIG. 2 relates to the case where 0 180)
  • the directivity ratio is approximately 2 1, whereas if the friction coefficient is varied to a, 0.5, the braking forces during the respective rotations will be 13 and A and accordingly the directivity ratio between these braking forces will be sharply increased from 2 l to 4.5 I.
  • the friction coefficient thus tends to increase with the use of the device.
  • the braking force provided thereby varies approximately in proportion to a value having the friction coefficient as the exponent thereof and such variation affects the directivity ratio so greatly that the latter increases even up to a ratio two or three times as high as an initially set value. More specifically, if the initially set directivity ratio is 2 1, the ratio will be increased to 4 1 l to 6 l, and
  • It is another object of the present invention to provide a brake device which comprises a brake band entrained on a braked drum, said brake band having their ends connected to a lever at two points therein, and resilient means interconnecting said lever and a fixed portion in such a manner that the end of said resilient means connected to said lever lies at apoint which divides the distance between said two points of said lever, said resilient means being designed so as to exert a component of force on the tight portion of said brake band during the rotation of said braked drum in either direction.
  • the brake band entrained on the braked drum is movable in the direction of rotation of the braked drum, whereby one end portion of the brake band engages stop means to provide a slack portion of the brake band in accordance with the direction of rotation of the braked drum while the otherend portion of the brake band provides a tight portion to which is imparted a spring force having a predetermined characteristic.
  • the friction coefficient can always be limited within a predetermined allowable value so that any inconvenience resulting from too great a variation in the friction coefficient may be completely prevented.
  • an allowable limit and the directivity ratio are determined only be the selection of the resilient forces for two springs, and this leads to the elimination of the need to pay minute attention to the materials forming the brake band and braked drum, the workmanship of such members, the value of coefficient of friction therebetween and other factors.
  • any variation in the friction coefficient during the use of the brake device may be substantially negligible.
  • the brake device according to the present invention is very excellent in working life and stability of performance as well as simple and easy to manufacture, and thus it eliminates the drawbacks peculiar to the prior art brake device.
  • FIG. 1 is a schematic front view showing an example of the brake device according to the prior art
  • FIG. 2 is a graph for illustrating the relation between the friction coefficient and braking forces provided by the device of FIG. 1;
  • FIG. 3 is a schematic front view showing an example of the brake device according to the present invention.
  • FIGS. 4 and 5 are similar front views but showing the device of FIG. 3 in different operative positions;
  • FIG. 6 is a graph for illustrating the relation between the friction coefficient and braking forces provided by the device of FIG. 3;
  • FIGS. 7 to 9 are schematic front views showing another example of the brake device according to the present invention, and illustrating the device in variousoperative positions.
  • FIG. 10 is a schematic front view showing the brake device of FIGS. 7 to 9 as applied to the reel device in a tape recorder.
  • FIG. 3 which shows an example of the brake device according to the present invention
  • a reel bed 101 and a brake band 102 entrained on a braked drum provided by the reel bed 101 One end 103 of the brake band 102 is secured to an arm 107 at one end thereof.
  • the arm 107 has a spring 105 connected thereto and is pivotally mounted by means of a shaft 106.
  • the arm 107 is normally urged by the spring 105 so as to engage stop means 108.
  • the other end 104 of the brake band 102 is connected to a spring 109 by means of a lever 110 mounted for pivotal movement about a shaft 112.
  • the resilient force of the spring 109 is selected to be at a lower level than that of the spring 105 so that the brake band 102 is normally urged by the spring 105 so as to maintain the lever 110 slightly disengaged with stop means 111.
  • the slight disengagement between the lever 110 and stop means 111 allows the brake band 102 to move in the direction in which the braked drum is rotated.
  • This arrangement is such that either the arm 107 or the lever 110 is automatically and selectively engaged with the stop means 108 or 111 in accordance with the direction of rotation of the braked drum.
  • An electromagnet 113 is provided to release the brake during the operation, and this electromagnet is provided with a plunger having a pin 1 14 studded at the lower end thereof.
  • FIG. 3 shows the brake device in a braking position. If the brake releasing electromagnet 113 is energized with the brake device in this position, the plunger is raised by the electromagnet so that the pin 114 studded in the plunger engages the lever 110 to rotate the lever counter-clockwise and thereby release the brake as shown in FIG. 4.
  • a braking force in the counterclockwise direction as indicated by an arrow b is imparted to rotate the brake band 102 together with the braked drum in the direction b so as to engage the lever 110 with the stop means 111.
  • the spring 109 has its resilient force nullified while the other spring 105 alone is at work, whereby there is established the relation as expressed by the aforementioned equation (4), which vmeans the same characteristic as that shown by a curve a" in FIG. 6. If a braking force is imparted to the reel bed 101 when it is rotating in the clockwise direction as indicated by an arrow a in FIG. 3, the arm 107 then engages the stop means 108 to nullify the resilient force of the spring 105 and leave the spring 109 alone at work. Thus, there is established the relation of the equation (4) as in the abovedescribed case of the counter-clockwise rotation, to thereby provide the same characteristic as that shown by the curve a.
  • the brake device of the present invention has the directivity ratio expressed as follows:
  • FIG. 7 there is shown another embodiment of the present invention.
  • This alternative example includes a braked drum 201 rotatably mounted on a shaft 202.
  • a brake band 203 is entrained peripherally of the braked drum 201 and has the ends thereof secured to a lever 204 at 205 and 206.
  • Resilient means 207 is provided between the lever 204 and a fixed portion 209 to interconnect them.
  • One end of the resilient means 207 is secured to the lever 204 at a point 208 which divides the distance between thepoints 205 and 206 into a desired ratio a b and the other end of the resilient means a la secured to a b portion 209.
  • Stop pins 210 and 21 1 are provided to restrict the movement of the lever 204.
  • T represents the tension produced in the slack end portion of the brake band 203 during the rotation of the braked drum 201 in the direction A, e the base of natural logarithm, p. the coefficient of friction between the braked drum 201 and the brake band 203, and 0 the angle of contact of the brake band 203 with the braked drum 201.
  • T represents the tension produced in the slack portion of the brake band 203 during the rotation of the braked drum 201 in the direction B.
  • FIG. shows the braking device of the present invention as applied to the reel mechanism of a tape recorder.
  • Numeral 212 denotes a plunger type electromagnet having a braking rod movable integrally therewith. Movement of the braking rod 213 controls the release of the brake band 203.
  • the brake device of the present invention comprises a brake band entrained on a braked drum and having their ends connected to a lever at two points thereof, and resilient means interconnecting the lever and the fixed portion of a tape recorder.
  • the end of the resilient means connected to the lever is located at a point which divides the distance between the aforesaid two points of the lever into any desired ratio, so that a component of force is exerted on the brake band during the rotation of the braked drum in either direction.
  • the directivity of the braking force is not affected at all by the friction coefficient, but is always maintained at a predetermined ratio.
  • the present invention provides an ideal brake device which is free from any trouble such as breakage of the tape and which is simple in construction as shown in the foregoing embodiments.
  • a brake device comprising:
  • a first spring means having one end connected to said one end of said arm and having the other end fixed stationary;
  • a second spring means having one end connected to said one end of said lever and having the other end fixed to a stationary member
  • first and second spring means are arranged such that when the brake device is shifted into a braking position said brake band is pressed against the braked drum due to the tension of both said spring means;
  • a second stop means fixed near said lever and said second spring, said second stop means being spaced at a predetermined distance from said lever, whereby one end portion of said brake band is hindered from further movement when at least one of said arm and said lever engages one of said corresponding stop means in accordance with the direction of rotation of said braked drum to provide a slack portion of said brake at said one end which is free from any spring force while the other end portion of said brake band provides a tight portion to which is imparted a predetermined spring force.
  • a brake device comprising:
  • first and second stop means respectively fixed to stationary means near said ends of said lever and spaced at predetermined distances from said ends
  • said resilient means exert a component of force on the tight portion of said brake band during the rotation of said braked drum in eigher dirsctign.

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  • Braking Arrangements (AREA)
US24219A 1969-10-07 1970-03-31 Brake device in tape recorder Expired - Lifetime US3651899A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP44080056A JPS5028806B1 (ja) 1969-10-07 1969-10-07

Publications (1)

Publication Number Publication Date
US3651899A true US3651899A (en) 1972-03-28

Family

ID=13707563

Family Applications (1)

Application Number Title Priority Date Filing Date
US24219A Expired - Lifetime US3651899A (en) 1969-10-07 1970-03-31 Brake device in tape recorder

Country Status (8)

Country Link
US (1) US3651899A (ja)
JP (1) JPS5028806B1 (ja)
BE (1) BE748363A (ja)
CA (1) CA932675A (ja)
DE (1) DE2015582B2 (ja)
FR (1) FR2048369A5 (ja)
GB (1) GB1309270A (ja)
NL (1) NL146915B (ja)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0091207A1 (en) * 1982-04-02 1983-10-12 Ampex Corporation Loading apparatus for differential band brake
US4875558A (en) * 1989-03-16 1989-10-24 Otis Elevator Company Safety brake for escalators
US4891959A (en) * 1988-07-01 1990-01-09 Whirlpool Corporation Bi-directional pivot band brake for automatic washer
US4947069A (en) * 1989-06-08 1990-08-07 Datatape, Inc. Low power magnetic tape reel motor and brake assembly
US6062148A (en) * 1997-08-01 2000-05-16 Steelcase Development Inc. Height adjustable support for computer equipment and the like

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT357794B (de) * 1978-05-19 1980-07-25 Philips Nv Aufzeichnungs- und/oder wiedergabegeraet
EP0086272B1 (en) * 1982-01-20 1986-04-16 Allied Corporation Rotor for axial field electromagnetic devices and method of construction therefor
GB2167142A (en) * 1984-10-09 1986-05-21 Everaids Ltd Band brake

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE184585C (ja) *
US998976A (en) * 1910-05-20 1911-07-25 William Ford Moody Electric brake.
FR563517A (fr) * 1922-05-30 1923-12-07 Système et dispositif pour le freinage des véhicules avec la même puissance dans les deux sens de marche
FR592187A (fr) * 1924-03-25 1925-07-28 Mors Electricite Système de frein
US2641338A (en) * 1950-01-20 1953-06-09 Eaton Mfg Co Band brake
DE966666C (de) * 1951-06-12 1957-08-29 Westinghouse Bremsen Ges M B H Bandbremse fuer das Hubwerk von Hebezeugen
US3092345A (en) * 1960-11-14 1963-06-04 Rca Corp Braking mechanisms
GB961185A (en) * 1960-12-15 1964-06-17 George Alexander Black Improvements in or relating to braking apparatus

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE184585C (ja) *
US998976A (en) * 1910-05-20 1911-07-25 William Ford Moody Electric brake.
FR563517A (fr) * 1922-05-30 1923-12-07 Système et dispositif pour le freinage des véhicules avec la même puissance dans les deux sens de marche
FR592187A (fr) * 1924-03-25 1925-07-28 Mors Electricite Système de frein
US2641338A (en) * 1950-01-20 1953-06-09 Eaton Mfg Co Band brake
DE966666C (de) * 1951-06-12 1957-08-29 Westinghouse Bremsen Ges M B H Bandbremse fuer das Hubwerk von Hebezeugen
US3092345A (en) * 1960-11-14 1963-06-04 Rca Corp Braking mechanisms
GB961185A (en) * 1960-12-15 1964-06-17 George Alexander Black Improvements in or relating to braking apparatus

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0091207A1 (en) * 1982-04-02 1983-10-12 Ampex Corporation Loading apparatus for differential band brake
JPS58179953A (ja) * 1982-04-02 1983-10-21 アムペックス　コーポレーション 差動引張力負荷装置
US4466512A (en) * 1982-04-02 1984-08-21 Ampex Corporation Loading apparatus for differential band brake
JPH0412533B2 (ja) * 1982-04-02 1992-03-04 Ampex
US4891959A (en) * 1988-07-01 1990-01-09 Whirlpool Corporation Bi-directional pivot band brake for automatic washer
US4875558A (en) * 1989-03-16 1989-10-24 Otis Elevator Company Safety brake for escalators
US4947069A (en) * 1989-06-08 1990-08-07 Datatape, Inc. Low power magnetic tape reel motor and brake assembly
US6062148A (en) * 1997-08-01 2000-05-16 Steelcase Development Inc. Height adjustable support for computer equipment and the like

Also Published As

Publication number Publication date
NL146915B (nl) 1975-08-15
NL7004701A (ja) 1971-04-13
JPS5028806B1 (ja) 1975-09-18
DE2015582A1 (de) 1971-04-22
CA932675A (en) 1973-08-28
GB1309270A (en) 1973-03-07
BE748363A (fr) 1970-09-16
DE2015582B2 (de) 1971-12-16
FR2048369A5 (ja) 1971-03-19

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