# US 4,395,920 A · Digital stylus force gauge > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,395,920 A - Document ID: US4395920A - Status: Granted - Kind: A - Application number: 06/224,804 - Filed: 1981-01-13 - Granted: 1983-08-02 - Earliest claimed: 1981-01-13 - Assignees: Audio Dynamics Corporation - Inventors: Stephen L. Kurtin; Donald R. Chivens - Web page: https://patentgrep.com/patent/US4395920A ## CPC - G01L 1/005: {by electrical means and not provided for in G01L1/06 - G01L1/22} - G11B 3/10: Arranging, supporting, or driving of heads or of transducers relatively to record carriers {(guiding record carriers G11B17/00, driving record carriers G11B19/00)} - G01L: MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE (weighing G01G) - G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R) ## Abstract A device for measuring small units of force or weight, such as the tracking force of a phonograph cartridge, includes an elastic flexure member having an electric contact for engagement with an encoder. As the flexure member is deflected by an amount proportional to the force being measured, contacts on the encoder are sequentially activated to provide an electric signal used to drive on analog, digital or numeric visual display or readout of the measured force. The device of the invention may also include a mechanism for providing a second point of support for the flexure member and a second visual scale to provide a greater range of measurement. ## Claims ### Claim 1 A gauge for measuring a force comprising: a plurality of spaced electrical contacts; a leaf spring to which said force is applied, said leaf spring being fixedly mounted at one end to a fixed mounting means that provides a first point of support for said leaf spring; an electrically conductive wiper attached to said leaf spring so that when said leaf spring is deflected by said force said wiper engages said electrical contacts sequentially; means for providing a second point of support for said leaf spring to thereby provide first and second scale factors on said spring; bistable magnetic latch means for selectively locking said second point of support; a plurality of spaced indicators; and circuit means for energizing said indicators and for coupling each one of said indicators to a different one of said contacts so that as said leaf spring is deflected said indicators will be energized sequentially. ### Claim 2 (depends on 1) The gauge as claimed in claim 1, wherein said plurality of indicators are sequentially arranged, the spacing of said indicators being directly proportional to the spacing of said electrical contacts. ### Claim 3 (depends on 1) The gauge as claimed in claim 1 wherein said means for providing a second point of support includes a deflection edge displaceable from a first position out of engagement with said leaf spring to a second position in engagement with said leaf spring, whereby said leaf spring is selectively deflectable along said edge or about said first point of support. ### Claim 4 (depends on 1) The gauge as claimed in claim 1, wherein said wiper engages at least one of said spaced contacts, but not more than two of said contacts at any position. ### Claim 5 A displacement indicator which comprises: a plurality of spaced contacts; a wiper; a cantilever leaf spring having opposed ends, one end of which being fixedly mounted, said wiper being mounted to the other end of said leaf spring; means for adjusting the contact friction between said wiper and said spaced contacts, means for displacing said wiper and causing said wiper to engage said contacts sequentially; a plurality of indicators spaced from one another in accordance with the spacing between said contacts; and circuit means operatively connected to said indicators and contacts for energizing said indicators and for coupling said indicators to different ones of said contacts, whereby as said wiper is displaced said indicators are energized sequentially, the position of any one of said energized indicators being a function of the displacement of said wiper from a reference point. ### Claim 6 (depends on 5) The displacement indicator as claimed in claim 5, wherein said contacts are spaced by a substantially uniform distance. ### Claim 7 (depends on 5) The displacement indicator as claimed in claim 5, wherein the spacing of said contacts is directly proportional to the spacing of said indicators. ### Claim 8 (depends on 5) The displacement indicator as claimed in claim 5, further including a substrate, said contacts and said indicators being mounted on said substrate. ### Claim 9 (depends on 5) The displacement indicator as claimed in claim 5, wherein said wiper is constructed and arranged so that it engages at least one but not more than two of said contacts at any position thereof. ### Claim 10 A force gauge which comprises: a plurality of spaced contacts; a cantilever leaf spring fixedly mounted at one end to form a first point of support; a wiper attached to the other end of said leaf spring such that as said spring is deflected said wiper brushes said contacts sequentially; means for adjusting the contact friction between said wiper and said spaced contacts; means for applying force to said leaf spring; a plurality of spaced indicators, the spacing of said indicators being a function of the spacing of said contacts; and circuit means for energizing said indicators and for coupling each one of said indicators to a different one of said contacts whereby as said leaf spring is deflected said indicators will be energized sequentially. ### Claim 11 (depends on 10) The force gauge as claimed in claim 10, wherein said gauge includes means for providing a second point of support for said leaf spring to thereby provide first and second scale factors on said spring. ### Claim 12 (depends on 11) The force gauge as claimed in claim 11, wherein said gauge includes bistable magnetic latch means for locking said first and second point of support. ### Claim 13 (depends on 10) The force gauge as claimed in claim 10, wherein said contact friction adjustment means comprise means for displacing said wiper along a line perpendicular to the plane of said contacts. ### Claim 14 (depends on 10) The force gauge as claimed in claim 10, wherein said wiper and said contacts comprise dissimilar metals. ### Claim 15 (depends on 10) The force gauge as claimed in claim 10, wherein said wiper comprises a refractory metal and said contacts comprise a noble metal. ### Claim 16 A force gauge which comprises: a plurality of spaced contacts; a cantilever leaf spring fixedly mounted at one end; a wiper attached to said leaf spring such that as said leaf spring is deflected said wiper brushes said contacts sequentially; said wiper and said contacts comprising dissimilar metals; means for applying force to said leaf spring; a plurality of indicators; circuit means for energizing said indicators and for coupling each one of said indicators to a different one of said contacts whereby as said leaf spring is deflected said indicators will be energized sequentially; and means for labeling each of said indicators with a numeral, the numeral associated with each indicators being a function of the force required to be applied to said leaf spring in order to energize said indicator. ### Claim 17 A force gauge which comprises: a plurality of spaced contacts; a cantilever leaf spring fixedly mounted at one end; a wiper attached to said leaf spring such that as said leaf spring is deflected said wiper brushes said contacts sequentially; said wiper comprises a refractory hard metal and said contacts comprise a noble metal; means for applying force to said leaf spring; and decoding and display means coupled to said wiper and said contacts whereby a digital representation of force applied to said spring will be displayed.