US1191073A - Sextant. - Google Patents

Description

P. H. HAMMOND.

SEXTANT.

APPLICATION FILED JUNE 20, 1913.

Patented July 11, 1916.

3 SHEETSSHEET I.

. P. H. HAMMOND.

SEXTANT.

APPLICATION FILED JUNE 20, 1913.

1,191,073. Patented July 11, 1916.

3 SHEETS-SHEET 2.

P. H. HAMMOND.

SEXTANT.

APPLICATION FILED JUNE 20. 1913.

3 SHEETS-SHEET 3- 270 w i 290 25 f i 35 ZMQSLSPSJ mania":

Patented July 11, 1916.

rmm nus'ron HAMMOND, or 'rnn UNITED'STATES. NAVY.

Specification of Letters Patent.

1 Application med June 20,1913. Serial No. 774,786. 1

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To all whom it may concern I Be it known that I, PmLIr Hos'ron He n- MOND, of the United States ,Navy, a c1t1- zenof the United States, residing at An-z napolis, in the county of Anne Arundel and State of Maryland, have invented, or discovered certain new and useful Improvevisions of the act of March 3, 1883,

ments in Sextants, of which the f ollowin'g is a specification, reference being hadtherein to the accompanying drawings.

This application is made under the pro- Ch. 143: 22 Stat. L.- 625, and it is understood that the invention described herein, if patented, may be used by the Government, or any of its ofiicers or employees in the prosecution of work for the Government, or by any other person in the United States, without the payment tome of any royalty thereon.

This invention relates to sextants and has for its general object to provide means whereby thegraduated limb and vernier may be conveniently illuminated in order to facilitate the taking of nautical and'other observations in the dark. I

The more particular objects of the invention, together'with means whereby the same may be carried into eflect, will best be understood from the following description ofcertain forms or embodiments thereof illustrated in the accompanying drawings. It:

will be understood, however, that the constructions described-and shown have been chosen for illustrative purposes merely and that the invention'may beembodiedgin other forms without departing from the spirit and scope thereof. v v

In said drawingsFigure 1 is a plan view .of a sextant having my improvements applied thereto. Fig. 2 is a front view of the same. Fig. 3 is an enlarged vertical,

sectional view taken on a plane passing through the graduated limb and vernier arm. Fig. 4 is a plan view of a portion of the graduated limb 'and vernier arm showing a modified form of illuminating device. Fig. 5 is a side view, partly in section, of the parts shown in Fig. 4. Fig. 6 is a detail, sectional view taken substantially on the line 33, Fig. 5. Fig. 7 is a detail, perspective view of the contact members associated with the lamp shown in Fig. 5. V v Referring first to Figs. 1 to 3, the sextant proper may be 'of any usual or well known construction comprisingessentially a frame vernier 19.

12-, provided with a handle 13 and carrying a graduated are or limb 14 and a horizon glass 15, a telescope 16 rigidly mounted on frame 12, and a vernier or indicator arm 17 pivoted to the frame and carrying adjacent its pivot the usual index glass 18 and adj acent 1ts outer end the usual indicator or In accordance with the present invention the usual reading glass20 is-carried by a supporting arm 21 pivoted for movement at 22 on an arm 23 which in turn is pivoted for movement on-.the upper or outer end of a post 24 projecting from the vernier arm 17.

v Patented July 11,1916.

Adjacent'the usual vernier opening 25 in the arm 17,' and supported on said arm, as 'bya bracket 26, is a translucent screen 27 of any suitable material, preferably ground glass. Supported-by the arm'21 immediately in the. rear of the screen 27 is an incandescent' electric lamp 28, behind which is arranged a preferably concave mirror or reflector 29 carried by an arm 30 secured to the arm 21. For supplying current to the lamp,

28 there are provided wires or conductors 31 connected with said lamp in any suitable manner, extending rearwardly along the 'vernier arm 17, to'which they are preferably secured as by clips .32, and entering the handle 13, which is formed hollow to constitute a housing for a -dry battery of any usual type with which said conductors 31 are suitablyconnected. For controlling the current to the lamp 28 there is provided a rod or button 33 adapted to cooperate with any suitable -or well known form of switch or contact member within the handle '13, said rod or button being carried by a flat spring 34, secured to the end of said handle and 33 in a position to keep open-"the circuit to u the lamp, said rod or button being capable of being pushed inwardlyagainst the resistance of said spring, for the purpose of closingsaid circuit and causing said lamp to be facilitate reading the result of said observation, the rod or button 33-may be ushed inlifand wardly by the thumb or finger o the grasping the handle 13, whereupon the lamp 28 will be lighted, as above ex lained.. The

light from said lamp, reflecte and concenadapted normally to holdthe rod or button I readily observed in the dark.

I the construction of the sextant may be substantially as shown in Figs. 1 to 3, or otherwise, in accordance with any usual type. As in Figs. 1 to 3, 14 denotes the graduatedlimb Tn the modification shown in Figs.- 4 to v or are, 17 the Vernier or indicator arm, 19

the Vernier, and the Vernier opening in the arm 17 adjacent, Vernier 19 through which the graduations on the limb 14 may be observed. As in the form of the invention first described, a translucent screen 270 is arranged uponthe Vernier 'arm 17 adjacent the Vernier opening 25, and a reading glass' 200 is carried by the outer end of an arm 210 pivoted to an arm 230 which in turn is pivoted to a post 240 projecting from the Vernier arm 17. In this form of the invention, however, the lamp 280 and reflector 290 2 are carried'by a slide 35 mounted on the arm 210 and adapted,

to move longitudinally thereon and to be desired position. Also in this form of the invention the current to the lamp 280 is controlled by means ,of a switch comprising a pin 37 projecting from the lamp socket 38 in the slide and an angular spring contact member 39 secured to said slide, as by means of screws 40 passing through a cap 41 and It.

through openings in one arm of said contact member 39, and entering said slide 35. i The conductors 310 are connected respectively with the. lamp socket 38 and with the contact member 39. When it is desired to light the lamp 280 for the purpose of illuminating and reading the scale and Vernier, the contact member 39 may be pressed inwardly against held frictionally in any its own resilience into contact with the end of pin 37, therebyclosing the circuit to the 45 lamp. When using the instrument in the day time, or when for any other reason the use of the lamp is not desired, the slide 35 may be movedinwardly on the arm 210 and v out of the .way.

Having thus fully .described'my invention, I claim as new and desire to secure by Let ters Patent 1. The combination with' a mathematical instrument provided with a' graduated scale and an indicator arm adjustable relatively to the scale, the said instrumenthaving a handhold portion by held in position for use, of means for illuminating the scale comprising an electric lamp carried by and movable with the indicator arm, a batte arranged within the said handhold portion of, the instrument, circuit wires leading from the battery to the lamp, and'a circuit controlling switch adjacent to the battery.

2. The combination with a mathematical instrument provided with a graduated arc, an indicator arm and a .vernier adjustable relatively to theiar'c', the said instrument having a portion shaped as a handhold tor grasping; and supporting it in position for use, of means for illuminating the are comprising an electric lamp carried by and movable with the indicator arm, light reflecting and diffusing members associated with the lam a battery housed within the said handhol portion of, the instrument and in circuit with. the lamp, and a lamp controlling switch adjacent to the battery.

In testimony whereof I aflix my signature in the presence of two witnesses.

PHILIP HUSTON HAMMOND.

Witnesses:

EDGAR H, MAY, J. F. THORNTON.

which is grasped and

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