GB2597090A

GB2597090A - Mounting of a cartridge on a record player

Info

Publication number: GB2597090A
Application number: GB2010863.5A
Authority: GB
Inventors: Khoubesserian Arthur
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-07-14
Filing date: 2020-07-14
Publication date: 2022-01-19
Also published as: GB202010863D0

Abstract

An adapter 20 is used for correctly positioning and aligning a cartridge relative to a head shell of a pivoted pickup arm of a record player. The adapter comprises a member having at least one formation to mate with a, or a respective, locating formation that forms part of the head shell to locate the adapter plate relative to the head shell 10. The adapter may be shaped to fit in a recess 18 on the underside of the head shell. The adapter also has holes 22 positioned to coincide with elongate holes 16 in the head shell, for receiving the mounting screws of the cartridge so as to permit the cartridge to secured to the head shell in only one position located at a desired predetermined distance from the pivot axis of the pickup arm and is oriented with a predetermined inclination relative to the head shell. A kit comprising a plurality of adaptors may have adaptors with differing positions of the mounting screw receiving holes and locating formations.

Description

MOUNTING OF A CARTRIDGE ON A RECORD PLAYER Field of the invention The present invention relates to an adapter for correctly positioning and aligning a cartridge relative to a head shell of a pivoted pickup arm of a record player.

Background of the invention

There has recently been a resurgence in the sale and usage of vinyl records as the quality of the reproduced sound is deemed to be superior to that produced by digital recordings. To achieve excellence, modern record players use sophisticated, and therefore costly, technology in the design of the components, namely the turntable, the pickup arm, the cartridge, and the stylus. Each of these needs to be designed to high standards to is achieve quality superior to that of digital recordings.

Despite the excellence of the construction of all these individual components, sound reproduction using a turntable having a pivoted pickup arm inevitably requires a degree of compromise. This is because, when records are produced, a recording stylus is moved along a linear radial path relative to a rotating master disc. To reproduce the recorded sound faithfully would require the stylus to follow a similar path. However, this is not possible when using a record player having a pickup arm that pivots, because the stylus follows an arcuate path instead of a linear path. Nevertheless, by designing the pickup arm to be of an appropriate length and pivoted at the correct position relative to the turntable, it is possible to optimize the sound quality by ensuring that the stylus is correctly position relative to the sound track when the pickup arm is at the centre of its sweep, with minimum misalignment at the start and end of the record.

For these reasons, when mounting a cartridge on a pickup arm, the distance of the stylus from the pivot axis of the pickup arm is critical as is the orientation of the cartridge relative to the pickup arm If a pickup arm were to be designed to receive only one dedicated cartridge, one could ensure that the cartridge can only be assembled at the correct position and with the correct orientation. However, in practice, this is not the case and it is possible to mix pickup arms and cartridges from different manufacturers. As there is no standardisation in the dimensions of cartridges, pickup arms designed to accept different cartridges use -2 -elongate mounting slots to receive the cartridge mounting screws As a result, when fitting a cartridge to a pickup arm, great care is required in locating and orienting the cartridge because it can be mounted at a variety of distances from the pivot axis of the pickup arm and with a variety of orientations, and any mis-alignment can result in increased distortion For this reason, cartridge replacement can be time consuming and therefore costly. There is furthermore a risk of damage to the delicate stylus assembly during a protracted alignment process Object of the invention The present invention therefore seeks to simplify the mounting of a cartridge on a pickup arm of a record player, while ensuring correct positioning and orientation of the cartridge.

Summary of the invention

According to the present invention, there is provided an adapter for correctly positioning and aligning a cartridge relative to a head shell of a pivoted pickup arm of a record player, the head shell having elongate holes for receiving mounting screws of the cartridge, wherein the adapter comprises a member having at least one formation to mate with a, or a respective, locating formation that forms part of the head shell to locate the adapter plate relative to the head shell, and holes, positioned to coincide with the elongate holes in the head shell, for receiving the mounting screws of the cartridge so as to permit the cartridge to secured to the head shell in only one position in which the cartridge is located at a desired predetermined distance from the pivot axis of the pickup arm and is oriented with a predetermined inclination relative to the head shell The term 'head shell" is used herein to refer to the free end of a pickup arm designed to receive a cartridge. It may in some cases be formed integrally with the arm and in others it may be removable from the arm to assist in mounting the cartridge.

The adapter of the invention is specific to the cartridge and to the head shell. All head shells have at least one feature or formation that is specific to the head shell. The feature may be the shape of a recess, one of more holes in the head shell or possibly the outer perimeter of the head shell. For each head shell it is therefore possible to design an adapter to fit between the cartridge and the head shell that can only adopt a single position -3 -and orientation relative to the head shell. Once correctly positioned, the adapter can dictate the position of the screw holes for the specific cartridge for which it is provided.

It is envisaged in practice that adapters would be sold in kits, either for a specific cartridge or for a specific pickup arm. In the former case, the formations to mate with the pickup arm will vary between adapters of the kit, whereas in the latter case the mating formations will be the same and only the positioning of the holes for receiving mounting screws will vary between adapters in the kit.

Hitherto, it has been proposed to make mounting jigs that fit around a head shell and a cartridge to locate a cartridge as it is being screwed in position. While the cost of such a jig may be acceptable to a professional, it would not be practicable to sell a range of such jigs to an end user with a single cartridge nor with a single pickup arm. Unlike such a jig that it is intended to be reusable, the adapter of the present invention is an inexpensive component that is intended to the mounted permanently between a cartridge and a pickup arm.

Brief description of the drawings

The invention will now be described further, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a plan view from above of a head shell and an adapter of the invention, Figure 2 is a plan view from below of the head shell and adapter of Figure 1, and Figure 3 is a perspective view from below of the adapter fitted to the head shell

Detailed description of the drawings

The three figures show a head shell 10 to be fitted to the end of a pickup arm and secured thereto in a fixed position by a screw passing through a hole 12. A recess 13 on the underside of the head shell 10, seen in Figures 2 and 3, receives the end of the pickup arm (not shown). A finger 14 projects from the head shell 10 to enable the pickup arm and the stylus to be lowered manually onto the surface of a record and raised from it. Elongate holes 16 are provided to receive mounting screws of cartridge having a stylus, the holes being elongate in order to allow the cartridges of different manufacturers to be mounted on the head shell 10. -4 -

The head shell 10 as described above is entirely conventional and the provision of elongate holes is common on most head shells. A cartridge (not shown) to be mounted on the underside of the head shell typically comprises a body having generally rectangular sides with two captive nuts to receive two mounting screws inserted into the elongate holes 16 of the head shell 10. Each cartridge has projecting from its underside a stylus for engaging the tracks in the surface of the record. The position of the stylus relative to the captive nuts is not standard and therefore, to ensure the correct distance of the stylus tip from the axis of rotation of the pickup arm, different cartridges need to be secured to the head shell 10 with their mounting screws occupying different positions in the elongate slot la 16. Because of the elongation of the holes 16, it is also possible to mount a cartridge with an incorrect orientation, if its mounting screws do not lie on a line perpendicular to the length of the holes 16.

To avoid such incorrect mounting and to ensure that the cartridge is correctly is positioned and oriented relative to the head shell 10, the illustrated embodiment of the invention provides an adapter 20 shaped to fit accurately in a recess 18 in the underside of the head shell 10, as shown in Figures 2 and 3, and having two round holes 22 that line up with the elongate holes 16 to restricts the location at which the mounting screws of the cartridge should be inserted, thereby ensuring that the cartridge can be secured with only one position and orientation.

The adapter 20 is specific to the head shell 10 by virtue of being shaped to fit in the recess 18 but it may have a different shape depending on the head shell to which the cartridge is to be fitted. All that is required is that the head shell 10 and the adapter 20 should have mating formations that ensure their correct and precise alignment The adapter 20 is also intended for a specific cartridge and one intended for a different cartridge may have holes 22 in a different position relative to the formations designed to mate with the head shell. -5 -

Claims

CLAIMS1 An adapter for correctly positioning and aligning a cartridge relative to a head shell of a pivoted pickup arm of a record player, the head shell having elongate holes for receiving mounting screws of the cartridge, wherein the adapter comprises a member having at least one formation to mate with a, or a respective, locating formation that forms part of the head shell to locate the adapter plate relative to the head shell, and holes, positioned to coincide with the elongate holes in the head shell, for receiving the mounting screws of the cartridge so as to permit the cartridge to secured to the head shell in only one position in which the cartridge is located at a desired predetermined distance from the pivot axis of the pickup arm and is oriented with a predetermined inclination relative to the head shell.
2. A mounting kit for mounting on different cartridges on a head shell comprising a plurality of adapters as claimed in claim 1, wherein the adapters in the kit have the same mating formations as one another but differ from one another in the relative positions of the mounting screw receiving holes and the formations.
3 A mounting kit for mounting a cartridge on different head shells comprising a plurality of adapters as claimed in claim 1, wherein the adapters in the kit have formations that differ from one another to mate with different formations on the head shells