# US 4,397,013 A · Cantilever and phonograph pickup cartridge including said cantilever

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- Number: US 4,397,013 A
- Document ID: US4397013A
- Status: Granted
- Kind: A
- Application number: 06/014,750
- Filed: 1979-02-23
- Granted: 1983-08-02
- Earliest claimed: 1978-02-25
- Assignees: Kyoto Ceramic Co., Ltd.; Nagaoka & Co., Ltd.
- Inventors: Tadayoshi Shiomi; Toshihiko Nishioka
- Web page: https://patentgrep.com/patent/US4397013A

## CPC

- H04R 1/18: Holders for styli; Mounting holders on transducers
- H04R: LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS (producing sounds with frequency not determined by supply frequency G10K)

## Abstract

A cantilever for use in supporting a stylus tip of a phonograph pickup is disclosed, which consists of a pipe of a ceramic material composed mainly of aluminum oxide. This cantilever is light weight and has a high Young's modulus. When this cantilever is attached to a phonograph pickup, reproduction loss can be remarkably reduced over all the reproduction frequency range and sounds can be reproduced having good response characteristics.

## Claims

### Claim 1

In a phonograph pickup cartridge having a vibrantly mounted cantilever, a stylus tip fixed to one end portion of the cantilever, and a transducer mechanism for converting mechanical energy to electric energy connected to the other end of said cantilever, the improvment wherein said cantilever consists of a hollow pipe made of a sintered body of ceramic material composed mainly of .alpha.-Al.sub.2 O.sub.3, said pipe having an outer diameter of 0.4 to 0.6 mm and a thickness of 0.05 to 0.15 mm and said ceramic material having a specific gravity of 3.5 to 4.2 and a Young's modulus of at least 2.0.times.10.sup.4 Kg/mm.sup.2.

### Claim 2 (depends on 1)

A phonograph pickup cartridge as set forth in claim 1 wherein said ceramic material is composed of single crystal .alpha.-Al.sub.2 O.sub.3.