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Publication numberUS2775045 A
Publication typeGrant
Publication dateDec 25, 1956
Filing dateMay 4, 1954
Priority dateMay 4, 1954
Publication numberUS 2775045 A, US 2775045A, US-A-2775045, US2775045 A, US2775045A
InventorsKadlec Ladislav
Original AssigneeAmerican Machine & Metals
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Liquid filled magnetic compass
US 2775045 A
Abstract  available in
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

Dec. 25, 1956 L.. KADLEc LIQUID FILLED MAGNETIC coMPAss Filed May 4, 1954 INVENTOR n0/.smv /wzfc fw/5d@ ATTORNEY;

United States Patent() LIQUID FILLED MAGNETIC COMPAS Ladislav Kadlec, Lansdale, Pa., assignor to American Machine and Metals, Inc., New York, N. Y., a corporation of Delaware Application May 4, 1954, Serial No. 427,636 1 Claim. (Cl. 33-223) that parts must be compact yet access obtainable for y servicing.

One of the objects of the invention is to provide an improved compass arrangement having the desired sensitivity and yet being substantially unaffected by shock or vibration.

Another object of the invention is to provide an improved compass assembly arranged so that access can be obtained with ease to the various parts.

A still further object is to provide an improved means for mounting the front transparent panel or glass.

In one aspect of the invention, the compass has a bowl or chamber for receiving the liquid, the bowl having a yieldable support therein upon which is mounted the floating card holding the magnets and which bears the conventional indicia. An opening is located in the front of the bowl, said opening being closed by a transparent plate or panel through which the card or indicating means can be read. The frame of the compass may have an aperture or slot therein extending under the bowl for receiving an assembly including the compensating mechanism and a masking plate for the front of the compass. The transparent panel or glass closing the front aperture of the bowl may have a resilient metal seal ring which may be soldered at one edge to the glass and soldered at its other edge to the margins of the bowl aperture. The glass thus will be resiliently supported and will not require a sealing ring and pressure to be applied thereto. Furthermore, the glass may be disassembled by merely heating the front of the bowl.

These and other objects, advantages and features of the invention will become apparent from the following description and drawings.

In the drawings:

Fig. 1 is a sectional elevation.

Fig. 2 is a front view reduced in size.

Fig. 3 is a fragmentary front view with a portion of the card broken away.

Fig. 4 is an enlarged fragmentary broken section of the pivot support.

Fig. 5 is a fragmentary top view of the card assembly.

Frame 10 may have a bowl or chamber 11, said chamber 11 having a suitable compass Huid therein. The frame and bowl may be made of aluminum or other suitable non-magnetic material. Aperture 12 is at the front of slot 13 in the frame for receiving sub-assembly 14, said sub-assembly or carrier including a front masking plate 15 and the compensator assembly 16A.

The compensator assembly may be of any suitable type. The one illustrated includes two pairs of shafts located at right angles to each other, 17, 17 being one pair and the other pair being back of adjusting shaft 16. These shafts have transverse pieces of magnetized material. The shafts can be adjusted, and thus the compensation, by turning adjusting screws under indentations 19B and 19C of cover plate 19D. When shaft 16 is turned by engagement ofslot .19, worm 18 will turnmeshed gears 18A and thus rotate shafts 17. Screw 19A holds cover 19D in place.

When it is desired to adjust or replace the compensating mechanism, it is possible to do so in the present invention by removing screws 20 and drawing the carrier subassembly 14 forwardly and out of slot 13 in main frame 10. Masking plate 15 is a part of the assembly.

A lighting arrangement is seen at 21, connection thereto being at 21A, such being described in detail in copending application Serial No. 421,332, filed April 6', 1954. i

Bowl 11 has a front aperture 22 which can be closed by transparent panel 23 in a novel manner, such panel being glass or other suitable material. The panel or glass 23 has a C shaped or equivalently arranged eXible metal ring; 24 which may1be joined by soldering at edge 25 with the` glass.Y Edge 26 can be joined'to the margins of the bowl by soldering so as to form a tluid tight joint therewith. It can be seen that the mounting of the glass plate in the aperture does not require the usual gaskets and sealing mechanisms to hold it in place.

In assembling the parts, it is a simple matter to apply a soldering iron to the front of the frame 10 adjacent the aperture 22 so as to cause sufficient heat to be applied to effect soldering of ring 24 with its glass to the frame and thus close the front aperture of bowl 11.

In removing the glass, it is merely necessary to put the front of the casing on a hot plate.

Filling plug 27 can be provided in the top of the bowl. Cover 28 may be of suitable material held in place as desired by screws or in any other manner. Expansion capsules or bellows 29 communicate by means of passage 30 with the interior of bowl 11, the capsules providing an expansion chamber for the uid in the bowl 11. Passageway 30 is formed and located so that liquid flowing into the bowl from the bellows will be directed upwardly and away from the oat assembly 31. Such will tend to prevent undesirable eddies within the bowl.

A lubber line 32 is provided for receiving light through the port 33 in the manner described in said copending application Serial No. 421,332.

The oat or card assembly 31 may comprise cup shaped card 34 which can have figures or indicia pressed therein, said igures being suitably lled with marking paint. By indenting the figures, the card is stilened.

The oat assembly can be carried on the doughnut or tore shaped oat chamber 35, said float chamber being made in two parts 36, 37 as shown. The two parts of the oat can be made of light metal and pressure welded or bonded to withstand lluid pressure. The magnetic supporting element 38 has a formed portion 39 to which the oat assembly 37 with attached card 34 is assembled. Adjustable pivo-t member 40 can have screw threads thereon passing through nut 41, which is adjustable thereon, nut 42 being provided for holding the magnet supporting member 39 and the iloat assembly in adjusted position relative to each other. The height of the assembly relative to support 43 can be adjusted and the oat assembly and card can be rotated relative to the magnet assembly 38 so as to suitably align these parts relative to each other.

Magnets 44 are carried by the magnet carrying member 38. It is to be noted that by the construction involved herein the magnets are relatively low in the bowl and that the center of gravity relative to the support can be adjusted with ease'.

Pivot support 43 is arranged so as to hydraulically damp vibrations which might occur. This may be accomplished by providing a cylinder 45 carrying the pivot Restricted i aperture 49 is l providedx at.y theL upper part. of=

cylinder 4S v sothat fluidl r`canow `in. and .out` offthe cylin-` deras-theparts reciprocate; Thus,l in case-ofivibration1 therewill `be a dampinglmovement -fofthedloat assembly 31 relative to the frame. Conical spring SDfisarranged to urge the cylinder4S'upwardlyrrelative-to'the piston` 47, the spring'and yieldable support being .chosen so that the naturalfrequency ofthe bearing assembly issuch that when subjected -to movements withinl the vfrequency: range of the aircraft contact will' be maintained between the parts.-

It shouldbeapparent vthat variationsmay be made in details f of construction=without departing .from the spirit of the invention except as dened in the appended claim.


Ina Huid compass, the combination including'a. fluid filled bowl, ysaid bowl havinga chamber with concave vertical walls, a magnetic card having a centralhollow doughnut shaped oat in saidbowl supported on apivot therein, a transparent panel in one wall'of'said bowl for reading the card, and an expansion chamber connected to saidbnwl through a passage on one. ofsaidyettical. .911.-

cave faces of said chamberv above said card, the outlet axis of said passage into said bowl being directed upwardly toward the roof of said chamber and away from said card.

References Citedin thele of this patent UNITED STATES 'PATENTS 291,403 Ritchie V K Y Jan. 1, 1884 1,256,442 Creagh-Osborne etal. Feb. 12, 1918 1,679,764 Colvin Aug. 7, 1928 1,925,863 Crocker Sept. 5, 1933 1,993,548 Holmes Mar. 5, 1935 2,202,154 Kollsman. May 28, 1940 2,242,126 Holmes et al. May 13, 1941 2,280,726 Sperry Apr. 21, 1942 2,316,777 Fell Apr. 20,1943 2,402,638 Krasnow et al; June 25, 1946 FOREIGN', PATENTS 679,074 France Jan. 5, 1930 48,475 France Nov. 29, 1937 (1st addition toNo.r 798,520)

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US291403 *Jan 1, 1884 Mariner s compass
US1256442 *Jul 1, 1916Feb 12, 1918Frankn O Creagh-OsborneMagnetic compass.
US1679764 *Oct 11, 1922Aug 7, 1928Morris M TitteringtonMagnetic compass
US1925863 *Sep 16, 1929Sep 5, 1933Gen ElectricCompensating mechanism for compasses
US1993548 *Dec 7, 1929Mar 5, 1935Ruth V HolmesMethod of and apparatus for controlling by sensitive indicators
US2202154 *May 25, 1936May 28, 1940Square D CoAperiodic compass
US2242126 *Jun 25, 1940May 13, 1941Bendix Aviat CorpRemote indicator
US2280726 *Jun 10, 1939Apr 21, 1942Sperry Prod IncMagnetic compass
US2316777 *Aug 1, 1940Apr 20, 1943Fell William BMachinist's precision level
US2402638 *Sep 4, 1941Jun 25, 1946Kaufman Joseph M SMagnetic compass
FR48475E * Title not available
FR679074A * Title not available
FR798520A * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2941307 *Feb 4, 1955Jun 21, 1960Clare L FrisbieMagnetic compass
US3054581 *Jul 2, 1957Sep 18, 1962Globe Ind IncFlight control apparatus
US4601106 *Apr 12, 1985Jul 22, 1986Suunto OyVibration attenuator
U.S. Classification33/364, 33/356
International ClassificationG01C17/00
Cooperative ClassificationG01C17/00
European ClassificationG01C17/00