US1848057A - Tachometer - Google Patents

Tachometer Download PDF

Info

Publication number
US1848057A
US1848057A US292792A US29279228A US1848057A US 1848057 A US1848057 A US 1848057A US 292792 A US292792 A US 292792A US 29279228 A US29279228 A US 29279228A US 1848057 A US1848057 A US 1848057A
Authority
US
United States
Prior art keywords
rotor
magnet
frame
shaft
magnets
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US292792A
Other languages
English (en)
Inventor
Davey Clarence George
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Delco Electronics LLC
Original Assignee
AC Spark Plug Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to FR676122D priority Critical patent/FR676122A/fr
Application filed by AC Spark Plug Co filed Critical AC Spark Plug Co
Priority to US292792A priority patent/US1848057A/en
Priority to US340633A priority patent/US1862997A/en
Application granted granted Critical
Publication of US1848057A publication Critical patent/US1848057A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
    • G01P3/00—Measuring linear or angular speed; Measuring differences of linear or angular speeds
    • G01P3/42—Devices characterised by the use of electric or magnetic means
    • G01P3/44—Devices characterised by the use of electric or magnetic means for measuring angular speed
    • G01P3/49—Devices characterised by the use of electric or magnetic means for measuring angular speed using eddy currents
    • G01P3/495—Devices characterised by the use of electric or magnetic means for measuring angular speed using eddy currents where the indicating means responds to forces produced by the eddy currents and the generating magnetic field

Definitions

  • This invention relates to tachometersused to give visible indication of the speed of rotating members with which they are associated.
  • the object of this invention is to increase the magnetic field of such an instrument and thereby to make it more sensitive and its readings at low speed more accurate.
  • Other objects, such as simplicity in arrangement and economy in manufacture, will appear from the following description.
  • Figure 1 is a sectional view diametrically thru the improved tachometer.
  • Figure 2 is a fragmentary sectional view substantially on line 22 of Figure 1.
  • numeral 12 is a cup-shaped frame having an apertured stem 11 for the passage of a rotor shaft 10.
  • the rotor shaft is apertured to receive a driving connection with a' suitable shaft, preferably. a flexible shaft, which latter is to be connected to the rotatable member, the rate of rotation of which is to be measured.
  • the rotor shaft may have an annular groove 3 to receive a key 5 carried by the stem 11 to prevent axial movement of said shaft 10.
  • the stem 11 may be provided with a recess 21 containing a suitable wick 23 held in position by a cup 25. The purpose of the wick is to carry lubricant for lubricating the engaging surfaces of the stemll and shaft 10.
  • An outer casing 27 houses the frame 12 and its sleeve 29 is sufficiently extended to retain both the key 5 and the cup 25, as shown in Figure 1.
  • This casing 27 is secured to the frame by a plurality of'bolts 31 and nuts 33.
  • the bolts pass thru lugs or projections 35 and 37 formed on the frame 12, as shown in Figure 2.
  • An annular shoulder 45 in the frame supports a U-shaped magnet 13, the magnet hav- 1929. Serial No. 292,792.
  • a temperature compensat ing plate of known characteristics isplaced over the magnet poles.
  • a clip 46 is formed with an aperture by which it is dropped over bolt 31 and upon the extension 35.
  • the washer 49 and nut51 clamp the clip in position, its inner end -firm-. ly engaging the compensator plate 46.
  • Similar clips 46 on bolts 31 carried by lug 37'a'nd by the diagonally opposite lug, not shown, are used. These last-named clipsengage the flattened ends 53 of a bridge member 55, which is split as shown in Figure 2.
  • a rotor 9 is secured in any convenientway to the upper end of shaft 10. As illustrated,
  • the end of shaft 10 is reduced to receive on the shoulder so formed the opening within the rotor member 9 and thereafter the extreme end of the rotor shaft is 'crimped to hold the rotor in position.
  • the rotor is formed with a plurality of radial arms 57 as shown. WVithin the open end of the rotor shaft is a carrier 59 having in its lower end an end thrust bearing 61 and near its upper; end, a hole jewel 63. Secured by threads in the intermediate part of the bridge is a second bearing carrier having a passage therethrough and a hole jewel 65; The-open ings in the hole jewels 65 and 63 are in alignment and together with end bearingol provide the necessary bearing support for a spindle 67.
  • a metallic disc 14 designed to serve as a drag member and to be rotated by'the eddy currents against the tension of a spring 71 secured to said spindle and to a rotatable adjustment.
  • the'degree of rotation of drag disc 14 depends upon the rate at which the rotor 9 travels, cutting as it travels the magneticlines of force between the magnet poles.
  • a clip 7 3 rests on the bridge 55 and is apertured' to rotate about the extended end 1 of the carrier 65.
  • the clip extends across the bridge and on one side is bent down, as at 75, and secured to the lower end of the bent down portion 7 5 is the outer end of spring 71.
  • the other end of the clip is given a double bend and resiliently engages by its extended end (forked as at 77) the under side of the bridge. Rotation of the clip serves to Vary the tension of spring 71.
  • a part 7 9 carrying an indicating needle 16 balanced by an opposite end part 81.
  • the needle moves over a dial plate 19, the peripheral portion of which engages the marginal flanges of the casing 27.
  • a glass cover and a fastening bezel which parts are conventional and not illustrated.
  • a second magnet 18 is secured to the base of the frame by fastening means 83.
  • This second magnet thus lies under the rotor 9 and the disc let, while magnet 13 lies above these parts.
  • the use of this second magnet increases the intensity of the magnetic field and it is found to aid in giving accurate readings at low rotor speeds.
  • the invention is obviously simple and easy to construct and is quite inexpensive.
  • the magnets, the rotor and the drag disc are all in parallelism wherby an exceedingly compact arrangement results.
  • cup-shaped frame having spaced parallel surfaces, C-shaped magnets mounted in parallel spaced relation on said surfaces, said magnets having their corresponding poles in axial alignment, a rotor shaft extending through the base of said cupshaped frame, a rotor terminally carried by said rotor shaft and positioned in the space between the said magnets, a drag disc also positioned between said magnets, a spindle carrying said drag disc and journaled coaxially with said rotor shaft, said spindle ex tending axially beyond the region of the magnets, and an indicating member carried bysaid spindle.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Dynamo-Electric Clutches, Dynamo-Electric Brakes (AREA)
US292792A 1928-07-14 1928-07-14 Tachometer Expired - Lifetime US1848057A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
FR676122D FR676122A (es) 1928-07-14
US292792A US1848057A (en) 1928-07-14 1928-07-14 Tachometer
US340633A US1862997A (en) 1928-07-14 1929-02-16 Tachometer jewel frame and drive shaft retainer

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US292792A US1848057A (en) 1928-07-14 1928-07-14 Tachometer

Publications (1)

Publication Number Publication Date
US1848057A true US1848057A (en) 1932-03-01

Family

ID=23126216

Family Applications (1)

Application Number Title Priority Date Filing Date
US292792A Expired - Lifetime US1848057A (en) 1928-07-14 1928-07-14 Tachometer

Country Status (2)

Country Link
US (1) US1848057A (es)
FR (1) FR676122A (es)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3152485A (en) * 1961-06-09 1964-10-13 Northrop Corp Magnetic accelerometer
US3768315A (en) * 1971-02-10 1973-10-30 Stewart Warner Corp Speedometer and odometer assembly

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1085323A (fr) * 1952-11-12 1955-01-31 Daimler Benz Ag Instrument indicateur fonctionnant sans bruit, en particulier compteur de vitesse pour véhicules

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3152485A (en) * 1961-06-09 1964-10-13 Northrop Corp Magnetic accelerometer
US3768315A (en) * 1971-02-10 1973-10-30 Stewart Warner Corp Speedometer and odometer assembly

Also Published As

Publication number Publication date
FR676122A (es) 1930-02-19

Similar Documents

Publication Publication Date Title
US1848057A (en) Tachometer
US2795955A (en) Liquid level gauge
US2367950A (en) Electrical measuring instrument
US2073153A (en) Speedometer
US1760857A (en) Hair-spring-securing means for instruments
US2046163A (en) Speedometer
US1922610A (en) Tachometer
GB942655A (en) Improvements in or relating to bearings
US2073152A (en) Speedometer
US3240072A (en) Speedometer
US1708900A (en) Adjustable device for instruments
US1472198A (en) House electric
US2710377A (en) pfeffer
US2141445A (en) Magnetic speedometer
US2493376A (en) Magnetically biased indicating instrument
US2364724A (en) Electrical meter
US1597327A (en) Meteb
US2720603A (en) Speedometer temperature compensation
US1760844A (en) Speedometer
US1924816A (en) Directional gyroscope for borehole testers and other uses
US2336172A (en) Tachometer
US1999347A (en) Electric tachometer
US2720604A (en) Low-temperature compensating alloy for magnetic instruments
US2949552A (en) Magnetic drives notably those of tachometers
US1697580A (en) Speedometer