Accelerometer

• US 4,807,475 A
• Filed: 09/02/1987
• Issued: 02/28/1989
• Est. Priority Date: 09/02/1987
• Status: Expired due to Fees

• Current Assignee: Tentel Corporation
• Original Assignee: Tentel Corporation
• Inventors: Graham, Wayne B.
• Primary Examiner(s): Chapman, John
• Application Number:
  US07/092,065
• Time in Patent Office: 545 Days
• Field of Search: 73/492, 73/514, 73/515, 73/516 R, 73/517 R, 33/401
• US Class Current: 73/492
• CPC Class Codes: G01P 15/04 for indicating maximum value

Abstract

An accelerometer has a single pendulum-type acceleration sensitive element, the movement of the pendulum moving a pointer through a gear arrangement such that scale graduations on a face of the instrument may be linear or of other character. Auxiliary pointers are provided so as to indicate the maximum positive and negative values of acceleration experienced by the instrument, maintaining always the highest magnitude reading attained. The recording auxiliary pointers are manually resettable from outside the instrument.

Claims

1. An apparatus for measuring acceleration comprising:

a first shaft;

a pendulum fixed to said first shaft such that movement of said pendulum causes rotation of said first shaft;

a first gear member attached to said first shaft, said first gear member having a portion with gear teeth on an internal arc;

a second shaft parallel to and spaced apart from said first shaft;

a second gear member attached to said second shaft, said second gear member being an external gear and engaging said first gear member such that said second shaft rotates in the same rotary direction as said first shaft;

a first pointer attached to said second shaft for indicating the rotation of said second shaft;

a dial face adjacent to said first pointer, said dial face having a scale to indicate the amplitude of movement of said first pointer;

a second pointer rotating about the same center as said first pointer, said second pointer operable by said first pointer in one rotary direction, said second pointer for indicating the maximum movement of said first pointer in said one rotary direction;

a frame for supporting said first and second shafts, said pointers and said dial face; and

,

mounting means connected to said frame for mounting said apparatus to another body.

2. An apparatus as in claim 1 further comprising a third pointer rotating about the same center as said first and second pointers, said third pointer operable by said first pointer in an other rotary direction from said second pointer, said third pointer for indicating the maximum movement of said first pointer in said other rotary direction.

3. An apparatus as in claim 1 further comprising a damping means for preventing undesired movement of said pendulum of said apparatus.

4. An apparatus as in claim 3 wherein said damping means comprises a chamber enclosing said pendulum, with a portion of said pendulum being immersed in a viscous fluid contained in said chamber.

5. An apparatus as in claim 1 wherein said second pointer has a portion accesible with said apparatus mounted in a test position, such that said second pointer may be independently moved relative to said dial face.

6. An apparatus as in claim 2 wherein said third pointer has a portion accessible with said apparatus mounted in a test position, such that said third pointer may be independently moved relative to said dial face.

7. An apparatus for measuring acceleration comprising:

pendulum means for sensing said acceleration, said pendulum means constrained to swing in a vertical plane, vertical being defined by the local direction of gravity;

first gear means moving with said pendulum means such that said first gear means rotates about its center of rotation in the same direction as said pendulum means as said pendulum means swings;

second gear means pivoted separately from, and coupled to, said first gear means such that said second gear means rotates in the same angular direction as said first gear means; and

pointer means attached to and pivoted together with said second gear means for indicating the angular displacement of said second gear means;

said pointer means extending in the opposite direction from said pendulum means, such that an acceleration of the apparatus perpendicular to the vertical in a first direction that is parallel to the vertical plane of the pendulum causes said pointer to pivot toward the first direction, and an acceleration of the apparatus in a second direction that is opposite the first direction causes said said pointer to pivot toward said second direction.