Gravity-measuring apparatus

Claim 1

Apparatus for measuring the acceleration by gravity comprising: substantially a spherical body; a first switch means including engaging means for holding and thereafter releasing said body, said first switch means being closed only after the release of said body by said bodyengaging means; a second switch means including receiving means for said body positioned a known distance below said body-engaging means, said second switch means being opened only when said body is received by said engaging means, said second switch means comprising first and second plates of nonconductive material, said plates being positioned in the same plane with an edge of one plate opposite a corresponding edge of the other plate, said edges being provided with corresponding semicircular cutout portions, at least a portion of the remainder of said edges having an electric contact means, a hemiconical surface member fixed to each plate in the region of the cutout portions; and biasing means for biasing said plates to move toward each other so that when said body is not supported by said hemiconical surface members said electric contact means are in contact and said second switch means is closed, and when said body is supported by said hemiconical surface members said electric contact means are separated and said second switch means is open, said biasing means comprising a frame member and springs connected thereto under compression for supporting said first and second states; an electric timer means, and a source of electric current, said first and second switch means, said electric timer means and said source of electric current being serially connected so that said timer means only operates when both of said switch means are closed.