JPS632196B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention has a needle arm extending substantially the length of the pick-up and supporting a stylus tip at one end, the needle arm having at least one coupled to an electro-mechanical converter;
Furthermore, it is held elastically on a needle support, which is adapted to be supported by a clamping device on the casing of the pick-up in order to easily replace the needle, with the clamping device holding the needle in place. The cartridge is brought into the operating position by a guiding movement of the needle, and the guiding movement of the needle is substantially transverse to the longitudinal axis of the pick-up.

If it is advantageous or essential to guide the needle support arm in a direction transverse to the longitudinal axis of the pick-up into a position where it is connected to an electro-mechanical converter, the pick-up needle performs an exchange movement in this direction. is used. This is suitable, for example, in the case of pickups with ceramic transducers.
This is because if you do not do this and push in the longitudinal direction,
This is because the elastic coupling member between the exchanger and the needle arm is subjected to stress in the longitudinal direction of the needle arm. In magnetic systems with air gaps accessible only in the transverse direction,
A transverse needle exchange movement is necessary if it is desired to avoid changing a portion of the pole at any time.

The pick-up needle is not necessarily located in a convenient location for cleaning the record player, and although it should be possible to replace the needle by the user of the device as much as possible, the pick-up needle is a relatively small and precise object. To solve this difficult problem, a large number of devices are known up to now, but none of them presents a satisfactory solution.

A relatively simple solution is, for example, to form the needle support in a U-shape, to insert the U-shaped leg from below into the casing of the pick-up, and to provide the U-shaped leg with a predetermined guide in addition to the holding force. (Federal Republic of Germany Patent Application Publication No. 1112840, Federal Republic of Germany Utility Model Registration No. 1789402). A disadvantage of such an arrangement is that it is difficult to see at a glance where the support is to be attached. This is because the guide section of the housing is formed only by a relatively shallow cutout, and the housing usually consists of a plastic part of a single color, and from an aesthetic point of view black is preferred. In addition, because the guide path for the insertion movement is relatively short, a single push-in does not necessarily immediately result in the desired guide movement in the region of the transducer coupling position (inclined mounting). It is not satisfactory to have the needle held in the correct position after repeated attempts. There is a risk of damage by then.
As far as piezoelectric transducers are concerned, the coupling member may be stressed in at least one of its forward and backward directions. Also, because of the small spring stroke, the needle must be pulled forcefully to overcome the often significant holding force in order to release the needle from the holding force. The sudden decrease in force when removing the needle can cause uncontrollable movement, which would be difficult if the pick-up were to remain in the arm during needle exchange, which would be desirable in itself. In particular, there is a risk of causing damage.

Another known method (DE 1472048) proposes first inserting the rear part of the support obliquely behind the projection of the pick-up casing and then pushing the front part of the support towards the casing. The support is guided by the rocking movement of raising and is locked there. The advantage of this device over the previously described devices is that the support must be mounted clearly towards the abutment.
The position of the support during installation must be clearly defined with respect to the longitudinal direction of the pick-up.
However, although the orientation with respect to the longitudinal axis of the pick-up is simple and visible due to the longitudinal cut-out in the casing, the longitudinal cut-out is necessarily on the underside of the casing, so that at least this cut-out The rear end is not so easy to see.

The disadvantages of both of the above solutions are, inter alia, that during the process of guiding the support into the operating position, it is necessary to support or guide it with both fingers until just before the operating position, which is often difficult. , because of the limited lifting range of the tone arm, the mounting movement must be carried out transversely to the longitudinal direction of the finger.

Cartridges are also known which do not have the above-mentioned disadvantages for different types of pickups than the object of the present invention. In this case, the air gap relates to a magnetic pick-up which is accessible in the longitudinal direction of the pick-up and the needle/mover unit is guided in this direction (DE-A-2159573). However, this type of cartridge cannot be used for the needle or pick-up object of the present invention.

The solution according to the invention is based on a new needle exchange method in which the guiding movement of the needle necessarily takes place in two directions. In this case, the first guiding movement in the longitudinal direction of the pick-up has already been put into practical use in other types of pick-ups different from the object of the present invention, but in the present invention, this guiding movement simply moves the needle to a predetermined position. It is only used to bring it into an intermediate position, in which the needle automatically stops and from there performs its actual insertion movement perpendicular to the longitudinal direction. This movement is accomplished with a single finger push without any optical alignment aids.

Next, embodiments of the present invention will be described in detail using the drawings.

The casing 1 of the magnetic pickup according to FIGS. 1 to 3 consists of a plastic part 2, in which a shield 3 is housed, in which the pole pieces 4, 5 of the magnetic circuit of two transducer systems for stereo recording and playback are housed. sticking out from This pole piece is for guiding the magnetic movers 7, 8 and is accessible from below through an opening 6 in the bottom of the shield 3. Affiliated needle/movable unit (second
FIG. 1) consists of a support 9 and a needle arm which is fixed to the support by an elastic bearing 11. The needle arm 10 has each magnetic armature 7 of both transducer systems,
8 is fixed. The support 9 is in the form of a square tube, from which four spring arms 12-14
is protruding upward. The internal cross-section of the support 9 is adapted to the external shape of the shield 3, except for its height.
When the support 9 is fitted onto the shield 3, the upper wall 16 of the support abuts the upper surface 17 of the shield. At this time, the spring arms 12 to 14 of the support 9 slide along the lower surface 18 of the protrusion 19 of the casing, so that the support 9 cannot move at all except in the direction of the longitudinal axis of the pick-up. The movers 7 and 8 are designed not to collide with anything. The spring arm 12 is the abutment part 2 of the casing.
At the end position of the guiding movement of the needle in the longitudinal direction of the pick-up, which is determined by the contact with zero, the spring arms 12-14 engage in the recesses 21, 22 of the casing 1 of the pick-up. This cutout pushes up the spring arms 12-14, and thus the entire needle/mover unit, from below and guides it in a direction perpendicular to the longitudinal direction of the pick-up.
Both armatures 7, 8 then reach the operating position without any risk of damage, in which the spring arm 12
It is held by a spring force of ~14.

In the ceramic pick-up shown in FIGS. 4 and 5, a coupling member 23 for coupling the needle arm 24 to the transducer element conventionally projects from the underside of the pick-up casing. On the side of the pick-up casing 25, the U of the needle arm 24 is
Guide edges 28, 29 provided on the letter-shaped support 30
There are two longitudinal grooves 26, 27 for receiving. When the support 30 is inserted into the pick-up casing 25, these guide edges 28, 29 abut against the guide channels 31, 32 on the underside of the longitudinal groove 26 of the pick-up casing. Since the length of the spring arms 33-35 corresponds approximately to the width of the longitudinal grooves 26, 27 of the pick-up casing 25, only a longitudinal movement is possible, which allows the needle arm 24
can be matched with the coupling portion 23 without any hindrance. Even in this configuration, the vertical guiding movement is started only after the longitudinal insertion is completed, and the spring arms 33 to 35 are connected to the guiding notches 37 of the pick-up casing.
It engages with 38. The needle arm 24 is then engaged with the coupling member 23 by simply pushing it from below without tensioning the coupling member 23 forward or backward.

[Brief explanation of the drawing]

Figure 1 is a schematic perspective view of the magnetic pick-up with the replaceable needle/mover unit removed;
The figure shows the needle/mover unit of the pick-up shown in Fig. 1, and Fig. 3 shows the pick-up shown in Fig. 1.
4 is a schematic perspective view of the ceramic pick-up with the needle removed, and FIG. 5 shows the needle of the ceramic pick-up of FIG. 4. 1,25……Pickup casing, 9,3
0... Needle support body, 12-14, 33-35... Spring arm.

Claims (1)

[Scope of Claims] 1 Extending substantially in the longitudinal direction of the pick-up,
a needle arm supporting a stylus tip at one end, the needle arm being coupled to at least one electro-mechanical transducer and resiliently retained to the needle support; , the support is adapted to be supported on the casing of the pick-up by means of a clamping device in order to facilitate the exchange of the needle, the clamping device being brought into the working position by a guiding movement of the needle, and In cartridges in which the guiding movement of the needle is substantially transverse to the longitudinal axis of the pick-up, the needle impinges parallel to the longitudinal axis of the pick-up on the casing 1, 25 of the pick-up and on the support 9, 30 of the needle. longitudinal guides 3, 19, 9; 26, which determine the guiding movement up to the abutment 20;
28, transverse guides 21, 22; 33, 3 transverse to the longitudinal axis of the pick-up for guiding the needle into the operating position in the abutment position.
7, characterized in that the end position of the lateral guide is the functional position. 2 Longitudinal guide part 3, 19 on the casing side
9; 26, 28 are prismatic guide members, which guide the pick-up casings 1, 28 so as to accurately guide the supports 9, 30 in the longitudinal direction;
25. The cartridge of claim 1, wherein the cartridge extends over most of the length of 25. 3. The clamping device clamps the supports 9, 3 facing each other in the transverse direction as seen from the longitudinal direction of the pick-up.
Spring arms 12-14 provided at 0; 33-3
5, and the pick-up casing has a notch 2 for guiding the spring arms 12 to 14; 33 to 35 in the longitudinal axis direction of the spring arms.
1, 23; 37, 38 are provided, which recesses allow the spring arms 12-14;
Claim 1, in which the axis line coincides with 3 to 35.
Cartridge as described in section.