US170001A - Improvement in navigators bearing-indicators - Google Patents

Description

J'. D. LEACH. ITA/'IGA'IIORS:BEARIN'C'rrI1\TDI`J.AT0L7{,. No.170,001, Patented Nov.16,1875.

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N. PETERS. PHOTO-UTHOGRAFHER. WASHINGTON, D C,

'UNITED STATES PATENT OFFICE.

JOSEPH D.v LEAOH, OF `PENOBSOOT, MAINE.

IMPROVE'MENT lN NAVIGATORS BEARING-INDICATORS..

Specification forming partot' Letters `Patent No. 170,001, dated November 16, 1875; application filed May 17, m75.

equivalents: A bed-plate constructed and ar-1 ranged to be readily removed or iixed in position upon the part ofthe vessel from which the observation can be most conveniently made, this bed being provided with a iixed point, tel'med the lubber-mark, by which to adjust the revolving card, and a locking-screw for securing the card in position. This card revolves upon the central standard, and is subdivided into points, and marked like the common compass-card. The standard is secured and revolves in the center of the-bed, and at its base is provided with a locking-screwand indicating-point, which moves over the face of the card as the standard is revolved, and is locked in any desired position by the locking- Screw. In the top oi' this standard is pivoted4 (to allow a vertical adjustment) a tube' provided at one end with an eye-piece, and at the other with the usual cross-hairs, or with fine Wires. Upon this tube are holders, in which a telescope maybe laid, in the direction of the tube, and secured for use, when such an instrument may be necessary.

Figure 1 is a vertical section taken in the axial line ot' the tube. Fig. 2 is a top or plan view, with the sighting-tube partly broken away to show the movable indicating-point.

The bearing-indicators heretofore invented and patented by myself were only useful upon vessels in which the wheel was in the forward part, as they could only be used in direct connection with the compass; and hence upon vessels in which the steering-wheel is near the rudder-head, or aft the sails, they could only be used when the object to be observed was broad oft'77 the beam or quarter, as the sails obstructed the view forward, so that the'indicator could but seldom be used. To remedy these defects I have invented my present indicator, which in no case is used in connection with the compass, and which may be used upon any desired part of the vessel, such as the tat't'- rail, the rail upon the quarters, the bows, amidship, the windlass-bitts, or at the mast-head, `by simply providing` the means of .placing it in position, thus giving the navigator its full beneiit, without regard to the position ol' the object relatively to the vessel, and'enabling him to determine the position ot such object with the same accuracy that he determines the course his vessel is pursuing.

In the drawings, a is a section of the vessels rail, or a bed-piece to be secured to the vessel. b b are two pins, which are inserted in bed a, and which receive the ears c c ot' the indicator-bed (l, when it is placed in position for use. The pins b b must be so placed that a line passing through the center ot' each shall be exactly parallel with the midlship or central fore-and-aft line of the vessel. e is'the lubber-mark, a pin or indicator iixed in the raised rim or periphery of bed d, and exactly in the central line ot pins b. fis a set-screw, threaded in bracket g, 'and serving to lock the card 7L in` position. This card is marked with the usual compass-points, as shown in Fig. 2, or in such other equivalent manner as serves tot'acilitate its use. This card, when not locked by screw f, may be freely rotated upon bed d by means of pin i, secured in the card. j is the standard, pivoted and revolving in bed d, to which it is secured by screw-nut k. A set-screw, l, threaded in the base ofthe standard, and acting upon bed d, serves as the means ot locking the standard in position. m is apointer, formed upon or attached to the standard. n is the si ghtin g-tube, pivoted to the standard at 0, and ertically adjustable. This tube must exactly coincide with a line passing through the center of the standard and the end ot' pointer m. p represents the cross-hairs, and r the eye-piece. s is a telescope, which, when used, is laid in the curved bearings t t, secured upon tube n, a strap, u, serving to secure the telescope in place.

The practical use of this indicatorI will illustrate by reference to Fig. 2 in the drawings. Suppose the course to be pursued is due north until the object or land-mark bears northwest,

(when that course will be taken,) and that the vessel .has reached the position where she should haul up on the new course-the navigator, to verify this fact, will so adjust the card that the north point is at the lubber-mark e, as shown, and the card Will be so locked. The indicator is placed in position upon pins b, with the north point toward the head of the vessel, and the sightil1gtube 'it' brought to bear upon the land-niark7 When. itin the night7 it would be looked by screw l, and the indicator' taken to the light, and the pointer m being found upon the northwest point, would show that the Vessel should then be hauled up on the new course; but it in this supposed case the pointerml had been found to the West ot' northwest it would show that the vessel had not arrived at the point for changing its course,

is sailing, and then placing the indicator in position with point e toward the head of the vessel, when, by bringingl the sighting-tube to bear upon the land-mark, the pointer m will always indicate upon the card h thedirection (by compass) of such land-niark from the ves'- sel.

The telescope s may be used in the same manneras tube uri-u connection with the indicator. v

Wherever upon the vessel a pair of pins, b, are fixed parallel with the central line of the ves-sel, there the indicator may be used with the certainty oi' correct results.

I do'' not claim an indicator to be used in connection With the ships compass, as described in my said patents; but

' What l do cla-iin as my invention islna bearing-indicator, the combination ot' bed d, lulober-mark e, locking-screw f, ears c c,

rotating' standard j, locking-screw l, pointer m,

pivoted sighting-tube n, and cord h, substantially as described and shown. n

JOSEPH D. LEAOH. Witnesses:

CALVIN DAVIS, SEWALL LEAcH.

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