Maxometers (peak wind speed anemometers)

Claim 2

An instrument for measuring peak wind speeds of the character described comprising in combination: an elongated cylindrical outer casing member; a cylinder disposed in said casing member extending lengthwise thereof and in spaced relation therefrom; a nose cap and an end closure, affixed by retaining means to the forward and rearward ends of said casing, substantially sealing the same from the environment and supporting said cylinder in spaced relation to said casing; a piston reciprocally mounted in said cylinder, having a shaft projecting through an aperture in said nose cap and supporting a pressure disk plate responsive to wind pressure thereon; guided spring biasing means disposed in the cylinder and urging said piston forwardly in resistance to disk plate force; clutch means integral with said aperture and shaft allowing inward movement of said shaft responsive to wind pressure and fixing the same at the point of maximum pressure movement; and indexing means integral with said shaft and cylinder housing denoting a measure of wind pressure in connection with peak wind speeds.

Claim 3

An instrument as in claim 1, wherein said nose cap comprises an annular plug inserted in said casing member provided with a flange on the forward end thereof fitted over the end of said casing, said plug projecting inwardly and having an inner lengthwise bore therein for projection of said shaft and an outer shoulder fitting into said cylinder and yieldably supporting the same in spaced relation from said casing; and wherein said end closure comprises another annular plug circumscribed by and fitted into the rearward end of said casing member having an outer shoulder fitting into said cylinder and supporting the same in spaced relation from said casing.

Claim 4

An instrument as in claim 2, wherein the retaining means for said nose cap and end closure affixing the same to said casing member comprises at least two, oppositely positioned, lengthwise extending stress rods disposed between said cylinder and casing wall and projecting through said cap and closure with clamping means retaining the ends thereof, said rods being so disposed to absorb the compressive stresses of the spring biasing means and lengthwise expansion of the instrument components.

Claim 5

An instrument as in claim 1, wherein said spring biasing means disposed in said cylinder comprises: a substantially rearwardly extending coaxial tubular insert on said piston face providing a forward guide tube having an inner bore to receive compressable therein a coiled low rate linear spring, said forward guide tube having an outer surface to receive compressable thereon a coiled high rate linear spring; a substantially forwardly extending tubular projection fitted to said end closure providing an outer rear guide tube having an inner bore to receive compressable therein a coiled high rate linear spring; an axially extending inner rear guide tube of lesser diameter disposed within said outer rear guide tube affixed to said end closure and disposed to receive within the coils of said high rate spring a coiled linear low rate spring compressable thereon; a spacer collar disposed on said inner rear guide tube; a coiled low rate linear spring of diameter corresponding to and received by the bore of said forward guide tube and the surface of said inner rear guide tube, said spring extending in full flexion lengthwise of said cylinder in compressive contact with the face of said piston and the forward end of said spacer collar; a coiled high rate linear spring of diameter corresponding to and received by said outer rear guide tube affixed at its proximal end thereto, said spring surrounding said low rate spring and extending in full flexion lengthwise of said cylinder such a distance as to allow substantial compression of said low rate spring by the inwardly moving piston befoRe contact of the distal end of the high rate spring with the piston face, and providing thereafter the combined compressive reactive force of both of said springs.

Claim 6

An instrument as in claim 4, wherein associated with said spring biasing means is a zero calibration mechanism comprising: in combination with said spacer collar movably mounted on said rear guide tube, a keyway through the surface of said guide tube; an axially disposed threaded rod extending through said guide tube, journaled in said tube at its forward end and extending with a projection through the end closure supporting an affixed adjusting nut; a correspondingly threaded collar carried on said rod having a pin connecting through said keyway to said spacer collar, such that when said nut is adjustably turned said spacer collar will cause reciprocal movement of the flexed low rate spring allowing the free falling piston and shaft to zero calibrate said indexing means.

Claim 7

An instrument as in claim 1, wherein said clutch means comprises: said nose cap having an aperture providing a lengthwise bore chamber having an inwardly disposed shoulder; an annular cam member positioned in said chamber and affixed against said shoulder having an outwardly converging bore, receiving said piston shaft projecting therethrough, and providing a cam surface; an annular ball cage plug member provided at its forward end with an out-turned flange reciprocally mounted in fitting relation in said bore chamber; said plug member having a bore receiving said piston shaft and a shank portion movable against said shaft within the bore of said cam member; said shank of the ball cage plug member being provided with a plurality of circumferentially disposed bores opposite said cam surface and having reciprocal therein, in contact with said cam surface and shaft, balls responsive to a forward movement of said shank to be cammed inwardly against said shaft preventing forward outward movement thereof, but responsive to inward movement of the shank to release the same; and an annular spring positioned between the flange of said ball cage plug member and face of said cam member constantly urging said ball cage plug member forward.

Claim 8

An instrument as in claim 1, wherein said indexing means comprises: a plurality of graduate marks in spaced relation on said piston shaft corresponding to increments of wind pressure in terms of wind speed; and the forward edge of said nose cap constituting an indicator point in relation to said marks.

Claim 9

An instrument as in claim 1, for use in ambient environments, wherein the rearward end thereof is provided with fins responsive to orient said instrument and disk plate relative to wind direction to receive the maximum forces thereof.

Claim 10

An instrument as in claim 8, wherein the indexing means integral with said moving shaft and cylinder comprises: a transparent cylinder allowing visual observation of an indicator point on said piston face; a divided graduate scale having a lengthwise aperture for observation of the moving indicator point, said scale having marks in spaced relation thereon corresponding to increments of wind pressure in terms of wind speed; and a transparent panel on said casing member corresponding with said scale for observation thereof.