DE2029097A1 - Switching mechanism - Google Patents

Description

PATENT ADVOCATE
DIPL-ING. LEO FLEUCHAUS 2029097

8 MDNCHEM 71.

MelchioratraBe 42 My sign:

«1O8B-376

Motorola, Inc

9401 West Grand Avenue

ffranklin Park . Illinois

V.St.A

Switching mechanism

The invention relates to a switching mechanism BUS for reshaping a linear movement into a rotary movement with the aid of a double ratchet mechanism acting on a ratchet wheel a double ratchet disc made of flexible material

For converting a linear movement into a rotary movement Is it known to use a double ratchet mechanism to convert the opposite movement into a rectified rotary movement in a reciprocating linear movement, by pressing a! button on the double ratchet disc during one half of the rotary movement engages the element to be rotated and the other notch of the double ratchet disc during the opposite linear movement to the one to be rotated Element acts

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In Dar Hegel, switching mechanisms with which this reshaping can be carried out are provided with rigid double arms which have branches which engage on opposite sides of a ratchet wheel. The surface of the ratchet wheel is provided with teeth, in which one notch engages in the linear movement in one direction and the other notch in the counter-rotating linear excitation brought the ratchet wheel "the reciprocating linear motion is usually triggered by an electromagnet, which attracts an anchor when energized and when waste is energizing this again releases _β If only perform a purely linear movement during this reshaping the catches must anchor one have relatively großsen stroke ^ namely, since the latch via a hub shifted warden must ,, the one hand the Bev / egungsstrecke Gchaltradoa the other hand, an additional stroke distance includes _s which necessary so that the notch is disengaged again.

It has already been provided that such rigid detents are hinged to the armature of the .Elektromagneten, with a spring preload ensures that the notches on the ratchet wheel are resiliently engaged »although this reduces the armature stroke What at the same time enables a reduction in the power consumption of the electromagnet is this switching mechanism still unsuitable because it requires a large number of individual parts and is therefore relatively expensive in production

There is a reduction in the level for the switching mechanism particularly desirable for cassette tape recorders, for which such a switching mechanism is required to switch to the different tracks of a multi-track tape «, Das Cassette tape recorder has a control disc and a cam

- 2 - plunger

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plunger that engages this control disc and acts on the position setting of the magnetic head. This adjustment of the magnetic head takes place by turning the control disk on which the Hoeken plunger slides and, depending on the position of the control disk, lies in different levels. During the transition from one to the other level saga, the magnet head Fon is moved from the cam pusher into a different track position. In order to respect prevent misalignment of the magnetic head the track position, moreover, locking devices are provided, which hold the control disc in a certain position, after having taken these "These additional locking means bring about a further VergrSsserung the manufacturing cost of the switch mechanism and the tape recorder _o

Because of the relatively high acceleration that acts on the ratchet wheel due to the switching characteristic of an electromagnet, it is possible that the ratchet wheel and thus the control disk attached to it move over a switching path provided rotated out and thus eg executes two or more switching steps instead of one switching step. this however, this is undesirable and must be prevented by appropriate blocking devices. These locking devices are however, with the known switching mechanisms, they are relatively complicated and cannot be simplified without a loss of switching reliability.

The invention is based on the object of a switching mechanism with which a linear movement can be converted into a rotary movement, and with which as few individual parts as possible are required for the switching mechanism In particular, the double pawl disk should be constructed in this way be that it allows the largest possible rotary movement with the shortest possible stroke, using suitable devices it should be ensured that over-turning is avoided »

- 3 - ■. These

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This object is inventively achieved in _s that extend integrally from the frame of the double ratchet disc from two catches and old that are resiliently connected to the latches have projections which abut resiliently against teeth of the ratchet wheel, and da3S at least one Sperrfläch © provided on the frame of the double ratchet disc that rests on the ratchet wheel when the projections of the notches are shifted by a linear displacement in at least one direction in a certain position »

The switching mechanism according to the invention is to be particularly suitable for use in a cassette tape recorder, a further development of the invention being that there is an electromagnet with an armature, that a double ratchet disk is connected to the armature, which is made of a resilient material, and on which two detents are arranged in one piece at a distance from each other _e which cooperate via projections with teeth of a ratchet wheel so that the ratchet wheel resiliently rests on the teeth due to a linear displacement in a first direction on the ratchet wheel due to the electromagnet excited in the end-of-track position and this around rotate a certain part of the desired range of rotation, the linear displacement being limited by the interaction of locking surfaces with the ratchet wheel, and that when the excitation of the electromagnet drops, the double ratchet disc executes a linear movement in the opposite direction, w obei by the action of the notches on the ratchet wheel, the desired rotary movement of the control disc is completed.

Further features and advantages of the invention emerge from the following Description of an exemplary embodiment in conjunction with the claims and the drawing shown in the figures:

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Fig. 1 is a plan view of a push-pull double ratchet mechanism according to the invention for use in a tape recorder .;

FIG. 2 shows a side view of the lifting mechanism according to FIG. 1;

Figures 3, 4 and 5 each show a view of the lifting mechanism in one other operating position;

6 shows a perspective view of a control disk, as it is used in the tape recorder according to FIGS.

In the drawing, the same files are in the individual figures provided with the same reference numerals, the reference numeral 10 denoting a part of a cassette tape recorder is, in which a tape with a multiple track is used ο The tape device 10 comprises a magnetic head 12 that is attached to a bracket 14 is attached. To the magnet head in vertical To be able to adjust the direction with respect to FIG. 2 to the individual tracks of the tape, the holder 14 is with With the aid of a Fantograph, it is attached to the chassis 15 so as to be displaceable, Two pivot pins 17 and 18 of the pantograph are shown recognizable in the drawing.

On the bracket 14, a cam follower 19 is provided which due to the spring tension of one attacking the Fantograph Spring rests on a control disc 20 This control disc 20 has four different cam surfaces, each of which is assigned to a track of a four-track magnetic tape. The control disk 20 is on a shaft attached, which is rotatably mounted in the chassis 15 · As a result the rotation of the control disk at the end of the track of the magnetic tape, the bracket 14 with the magnetic head 12 is against the bias shifted the pen of the Fantograph in such a way that

■ - 5 - ■ the

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M1O8P-376 the magnetic head is moved to a different track position »

A housing 25 is also attached to the chassis 15, in which the capstan 23 of the tape device is mounted. To drive the This capstan 23 is connected to a flywheel 30, which is connected to a rotor 27 via a drive belt 28 stands. The rotating capstan 23 transports the magnetic tape past the magnetic head 12 from one end position to the other. In the tape device, the mechanism is generally constructed so that when reaching the end of the track of one Electromagnet a linkage is actuated, which rotates the control disk 20 and the magnetic head 12 in the desired new track position shifts. In the case of the one shown in FIGS Embodiment this is done by the actuation of the electromagnet 29 causes that briefly excited at the end of a track and an armature 31 attracts against the action of a spring 32 and releases it again. The anchor leads a and outgoing linear motion. When the excitation of the electromagnet 29 drops, the spring 32 acts on the armature 31 such that it falls into the position shown in FIGS Position is shifted back.

A double ratchet 33 eats with the front end of the Armature 31 connected and v / irkt on a four-pawl ratchet wheel 35, which is fostly connected to the control disk 20. The double pawl 33 is made of a thin resilient metal or plastic material made and has substantially Rectangular shape. In the center of the double ratchet 33 is a Opening provided in which formed integrally with the disc Notches 36 and 37 protrude. Runs through the opening the four-pawl ratchet wheel 35g with the one against the ratchet wheel engages spring biased at detents 36 and 37. the Spring preload of the notches is brought about by appropriately designed webs 39 and 40 which connect the notches to the double pawl disc in one piece.

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The whole double ratchet disc including the notches 36 and 37 and the webs 39 and 40 is made of a single resilient _t preferably Eunststoffmaterial manufactured and can be manufactured by spraying or stamping · Preferably there is in the Figure * 3 "4". And 5 shown construction ¥ This material used for the double pawl disc should be relatively rigid in the cured state and have good shrinkage properties, with a certain sufficient elasticity being present so that the detents 36 and 37 rest against the four-pawl ratchet wheel 35.

The mode of operation of the mechanism is particularly clear from FIGS. 3 to 5. When the solenoid 29 is energized and the anchor 31 attracts "d" h "with respect to FIGS. 3 to 5 shifts to the left, the projection 41 engages the catch 36 on a first tooth of the ratchet wheel 35.

The four-pawl ratchet wheel 35 is provided with four teeth 43, which essentially run radially outward with a curved surface, this curved surface with the projections 4-1 and 49 of notches 36 and 37 engages and due to the displacement of the double ratchet disk, a rotation of the ratchet wheel 35 is caused and 49 are at an angle from the notches 36 and 37 »so that they engage behind the projections 41 and 49 and cooperate with the curved surface 44 of the teeth located there.

When using the structure shown, it is possible to a relatively soft spring preload for the notches to use, since this always with the teeth 43 of the ratchet wheel 35 when actuated in Intervention come. If, on the other hand, the surface 44 of the teeth 43

- 7 - relatively

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verhältnisiaässig rectilinear "is © is ine stronger Federvorspannimg _t needed to prevent the projections 41 and 4-9 slide on the teeth 43 of the ratchet wheel during the displacement of the detents 36 and 37" The curved surface 44 dor teeth 43 provides a positive engagement without increasing the spring tension exerted by the webs 39 raid 40, as a result of which a more powerful electromagnet 29 would possibly be required.

When the projection 41 of the detent 36 comes into engagement with the first left tooth 43, the four-pawl ratchet wheel 35 and the control disc 20 are rotated by about 45 ° counterclockwise into the position shown in Fig The position of the armature 31, shown in FIG. 4 and drawn into the electromagnet 29, engages a locking surface 46 provided on the double ratchet disk on the rear side of a further tooth 50 of the four-jointed peeling wheel 35 in order to prevent the switching wheel from moving by more than half a tooth spacing, _e h, 45 ° _{t is} rotated as a result of the moment acting on the four-pawl ratchet wheel and the control disc 20 by the excitation of the electromagnet 29 »At the same time, the rear surface 48 of the double ratchet disc 35 counteracts a clockwise rotation of the ratchet wheel, as this rear surface 48 acts the tip of the next tooth strikes. If, for some reason, the four-pawl ratchet wheel 35 has not been rotated a full half tooth spacing due to the action of the claw 36, the interaction of the rear surface '48 with the tip of the next tooth tends to complete this rotation ",

Once the excitation is switched off from the electromagnet 29 causes the spring _t. 33 a pushing back of the double ratchet disk © 33 into the rest position, which is shown in FIG. As a result of this backward displacement, the projection 49 of the catch 37 acts on the curved surface of a further tooth 43 on the

- 8 - column wheel

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Ratchet wheel 35 "and turns it counterclockwise and thus the control disk 20 by a further range of rotation of approximately 45 °. This completes the desired 90 ° turn

When the notch 36 _{8 is} shifted to the left as shown in FIGS. 3 to 5, the projection 49 of the non-driving notch 37 slides on the rear curved surface 45 of the corresponding tooth 43 until the ratchet wheel 35 is in a position is rotated, in which the projection 49 of the catch 37 falls into the position shown in FIG 29 releases the armature and a reverse movement of the double pawl disk 33 takes place under the action of the spring 32. As a result of this movement, the double pawl disk 33 is displaced in the direction of a position according to FIG. 5 "until the projection 41 slides over the tooth edge when the double pawl disk 33 reaches the position according to FIG. 5",

As soon as the armature 31 has assumed the rest position shown in Fig. 5 after switching off the electromagnet 29, the projections 41 and 49 of the notches 36 and 37 old corresponding teeth 43 of the ratchet wheel come into engagement and block this in the given position to move of the ratchet wheel in Uhrsseigersinn, that is, to prevent a backlash * at the same time, ie _e when the double pawls disk is moved to the right end position 33, as shown in Fig. 5, engages a front blocking surface 50, the double ratchet disc 33 at a Tooth of the saw wheel and prevents further rotation in the counterclockwise direction due to the moment exerted on the ratchet wheel 35 during the return movement of the armature. In the position shown in FIG

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Furthermore, a projection 51 on the blocking surface 50 in the path of movement of the next tooth of the ratchet wheel 35 and causes a further blocking of a counter-rotation in the clockwise direction ₉ because this projection 51 is directly in the path of movement of the next tooth U-? lies. For d®n case that the movement dsr ßaste 37 through a slight rotation of the ratchet wheel 35 causes, 'strikes the projection 51 against the rear of the adjacent salmes 43 and rotates the four pawl-ratchet 35 i in the 3fig. 5 position shown "

Each activation and subsequent deactivation of the excitation of the electromagnet 29 causes one of the preceding descriptions corresponding step switching of the four-pawl ratchet wheel 35 and thus a rotation of the control disk to continue © 90 ° »

In fig. 6 the control disk 20 is shown in perspective »Si © comprises four cam surfaces 5 ^ to 57? which are arranged at different heights, each offset by 90 °. The JJockenflachen 5 ^ to 57 are separated from each other by inclined rising inclined surfaces 58, on which the squat ram 19 slides along at the transition from one of the cam surfaces 54 to 57 to an adjacent cam surface when the control disk 20 ma 90 °, Die Nockeiiflächen 54 bis 37 are located on different vertical levels, which extend with a relatively narrow tolerance in the different level levels. In order to be able to adjust the control disk to the position of the magnetic head 12 during assembly © in an individual tape recorder, an adjusting screw 60 is provided, with the aid of which the shaft 22 can be adjusted in the vertical direction according to FIG. 2 after the tape recorder has been assembled. With the help of this adjusting screw, the control disk 20 and the associated four-pawl ratchet wheel 35 can be adjusted by a small amount

- 10 - more vertical

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adjust the vertical direction ^ so that the magnetic head 20 can be adjusted precisely to the assigned tracks »

The double ratchet disk 33 is relatively thin in comparison -for the axial length of the four-pawl ratchet wheel 35, so that the adjustment of the ratchet wheel 35 in vertical Direction with the aid of the adjusting screw 60 has no influence on the assignment of the notches 36 and 37 to the teeth 43 ' Has. The resilient webs 39 and 40 keep the projections 41 and 49 in engagement with the ratchet 35 regardless of the set level level * · The level level remains the Double pawl disk 33 iia essentially in a right-angled position to the axis of rotation of the four-pawl ratchet wheel 35 and & sr control disk 20.

Since the notches 36 and 37 and the projections 41 and 49 rest against the ratchet wheel 35 with a certain preload through the webs 39 and 40, a slight misalignment of the longitudinal axis of the shaft 22 and thus a corresponding slight i ^? The four-pawl ratchet wheel 35 is tolerated within the opening of the double-pawl disc 33; "The mode of operation of the arrangement is not influenced by such a felling" If the armature and the detents were rigid on the other hand, an exact alignment of the shaft 22 with the armature and the detent arrangement would be absolutely necessary in order to prevent seizure of the detents or Avoid getting caught. .

By providing a 90 ° turn with each actuation of the solenoid 29, only four cam surfaces are necessary to adjust the magnetic head to the four different track positions normally used in conventional eight-track stereo tape recorders no 90 ° rotation would be caused _{y there} would be more than four cam surfaces on the control disk

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20 for the arrangement of the magnetic head in the respective positions of the individual track positions required »what at the same time a much more complicated mechanism with more critical ones Manufacturing tolerances, especially for the larger number the squatting surfaces, would require proper tracking for the magnetic head 12 during vertical displacement su ensure. By providing only one cam surface * for each track position in which the magnetic head 12 can be displaced is, the manufacturing costs for the control disk 20 of a cassette tape recorder can be significantly reduced.

The double ratchet mechanism described above converts a linear movement into a rotary movement by providing a double ratchet disc with locking surfaces that are made in one piece with the disc from a resilient plastic material particularly critical, so that the assembly of the tape device equipped with the mechanism is simplified and less critical due to the relatively large permissible tolerances «. If the double ratchet mechanism is used in a cassette tape recorder, the special arrangement and design of the double ratchet disc hold the control disc for setting the magnetic head in a certain position ₉ as soon as the magnetic head is brought into the position assigned to the track position. In addition, the DoppelkliAemecissaiisiinis © ine height adjustment of the magnetic head can be adjusted with respect to the assigned tracks without the engagement between the Doppelklimkenecfaeitne and the beepklimken-Slialt * wheel being adversely affected «," - "-

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Claims (1)

2029 09 / 12 «June 1970 «ΙοδΡ-376 Claims Switching mechanism for converting a linear movement into a rotary movement with the aid of a ratchet wheel Double ratchet mechanism with a double ratchet disc made of flexible material, characterized in that the double ratchet disc is located away from the frame (33) from two boxes (36, 37) extend in one piece and are resiliently connected to this that the catches Have projections (41, 49) resiliently attached to teeth (4-3) of the ratchet wheel (35), and that at least one locking surface (46, 50) on the frame of the double pawl disc is provided, which rests on the ratchet wheel when the gate jumps of the notches by a linear displacement in at least are shifted in one direction to a certain position, 2 · Switching mechanism according to claim 1, characterized in that the linear displacement of the Double pawl disc in one direction of the projection of a first detent in driving engagement with the ratchet wheel comes, whereas the projection of the other notch slides on the ratchet while rotating the same about the desired one Rotation range is applied, and that a linear displacement of the double pawl disc in the opposite direction Y09816 / -1 347 M108B-376 a driving engagement of the second box causes the ratchet wheel, while the only © detent during the completion the desired rotary movement is in sliding contact with the ratchet wheel 3- Schal taeehanismus according to claim I ₅ , characterized in that the frame of the double ratchet disc (33) essentially surrounds the ratchet wheel (55), and that two locking surfaces are attached to the frame _{s of} which • one (46) with the ratchet wheel the linear displacement in one sighting and the other blocking surface (50) comes into engagement with the ratchet wheel bsi the linear displacement in the opposite sighting and in each case limited the linear displacement 4. Switching mechanism according to one or more of the claims 1 to 3 «characterized in that the Double ratchet washer made from a plastic material and has an opening in its central area, which is penetrated by the ratchet wheel that the resilient connection of the notches resting on the ratchet wheel is in one piece with the double ratchet disc and the notches formed webs (39, 40) takes place, and that the locking surfaces are arranged on opposite sides of the frame of the Boppel pawl disc., Switching mechanism for cassette tape recorders in which a Tape storage with a large number of recording tracks is used, with a control disk which has a large number has different control surfaces, each of which is assigned to a specific track, to which a magnet head can be adjusted by the interaction of a cam follower with the control surfaces, and that means are available to rotate the valve disc in such a way that with the cam follower depending on the BATH ORIGINAL 109816/1347 M1O8P-376 Adjustment of the exchanged track a certain control surface comes into ■ engagement, thereby automatically bringing the magnetic head to the desired track position, thereby geke η η ζ e rejects that an electromagnet (29) with an armature (31) is present that with the Anchor is connected to a double pawl disc (33) _? which can be built from a resilient material _? and on which two hooks in one piece. Are spaced from one another, which projections (41, 49) interact with teeth (43) of a ratchet wheel (35) _t that the resiliently abutting on the teeth (43) Hasten by the excited in the Spurendlage electromagnets as a result of linear displacement in a first direction attack a ratchet wheel and turn it by a certain part of the desired range of rotation, the linear displacement is limited by the interaction of locking surfaces with the ratchet wheel, and that when the excitation of the electromagnet drops, the double disc disk executes a linear movement in the opposite direction, whereby the action the notch on the ratchet wheel completes the desired rotary movement of the control disc » Switching mechanism according to claim 5 »characterized in that that a further locking surface is provided on the double pawl disc, which the Mnearverschaltung the double ratchet disk limited in the opposite direction. 109816/1847 original bathroom