US3002280A

US3002280A - Beam compass

Info

Publication number: US3002280A
Application number: US715240A
Authority: US
Inventors: Jr Albert D Bennett
Original assignee: Individual
Current assignee: Individual
Priority date: 1958-02-14
Filing date: 1958-02-14
Publication date: 1961-10-03
Anticipated expiration: 1978-10-03

Description

Oct. 3, 1961 A. D. BENNETT, JR

BEAM COMPASS 2 Sheets-Sheet 1 Filed Feb. 14, 1958 in .i NW N wm M 0m P Q Wm m T we ::::c m 00. 2 OVI' Wm mm LY @N W AB @V Nw O h m NN vm W0 G Wm Oct. 3, 1961 A. D. BENNETT, JR

BEAM COMPASS Filed Feb. 14, 1958 2 Sheets-Sheet 2 nTfllllmn INVENTOR. ALBE m D Senna-133v. BY

77Zamzq 35W flank/4.071.

ATTOEMEYS 3,002,280 BEAM (IGMPASS Albert D. Bennett, in, 3109 Cornwall Road, Columbia, SC. Filed Feb. 14, 1958, Ser. No. 715,240 3 Claims. (Cl. 33--27) This invention relates to inscribing devices and, more specifically, the present invention pertains to a drafting instrument.

One of the primary objects of this invention is to provide a beam compass which may be quickly set roughly to a desired radius together with fine adjusting means for obtaining the exact radius.

Another object of this invention is to provide in a beam compass a radial beam which comprises a length of wire or a length of a solid bar.

A further object of this invention is to provide in a beam compass a pen holding base in which is incorporated means for finally adjusting the radial beam thereof, together with means for releasably locking the radial beam in its adjusted position.

A still further object of this invention is to provide a stabilized pen holding base for a beam compass of the type generally referred to supra whereby the base, upon release thereof by the draftsman, mechanic, or operator will remain substantially upright.

It is still another object of this invention to provide in a beam compass an inscn'ber housing with means for detachably connecting the same to one end of the radial beam, the housing also being provided with means for its stabilization whereby upon release thereof by the operator the housing will remain substantially upright.

This invention contemplates, as a still further object thereof, the provision of a beam type compass of the type generally referred to above, the compass being non-complex in construction and assembly, inexpensive to manufacture, and durable in use.

Other and further objects and advantages of the present invention will become more evident from a consideration of the following specification when read in conjunction with the annexed drawings, in which:

FIGURE 1 is a top plan view of a beam type compass constructed in accordance with the teachings of this invention;

FIGURE 2 is a longitudinal cross-sectional view taken substantially on the horizontal plane of line 2-2 of FIGURE 1, looking in the direction of the arrows;

FIGURE 3 is a vertical cross-sectional view, partly in elevation, this view being taken on the line 3--3- of FIGURE 2, looking in the direction of the arrows;

FIGURE 4 is a transverse detail cross-sectional view taken substantially on the horizontal plane of line 4-4 of FIGURE 2, looking in the direction of the arrows;

and

FIGURE 5 is a bottom plan view of the beam type compass illustrated in FIGURE 1.

Referring now more specifically to the drawings, reference numeral designates, in general, a beam type compass constructed in accordancewith this invention. The compass 10 is seen to comprise an elongated cylindrical normally upright main body portion 12 having an enlarged cylindrical flange 14 at the lower end thereof. A bore 16 extends inwardly from the lower end of the flange 14 in co-axial alignment with the main body portion 12, and the inner end of the bore 16 is in open communication with an undercut circumferential recess or groove 18 which rotatably receives a cylindrical flange 20integrally connected with the upper end of a depending substantially square rod 21 to the sides of which are secured a plurality of radially spaced downwardly extending and outwardly diverging stabilizing standards 22. As is seen Patented Get. 3, 1961 in the drawings, the upper ends of the standards 22 project through the bore 16. The standards 22 serve to support the main body portion 12 in a normally upright position on a support surface 24.

The main body portion 12 has a cylindrical bore 26 which extends diametrically therethrough adjacent the flange 14. The bore 26, intermediate its ends and at the upper side thereof communicates with a recess 28. The bore 26 receives for reciprocation therethrough an elongated cylindrical rack gear 30. From the upper side of said rack gear 30 projects a plurality of axially extending, uniformly spaced, and radially projecting gear teeth 32. I am teeth 34, 36 are provided at each respective end of the rack gear 30. A worm gear 38 having a shaft 40 meshes with the gear teeth 32 to effect reciprocation of the rack gear 30. The opposed ends of the shaft 40 are rotatably supported on the main body portion 12 and one end thereof extends exteriorly therebeyond and is enlarged and cut to form the gear 42. The gear 42. meshes with a second gear 44 from one side of which extends a cylindrical integrally formed centrally positioned shaft 46 suitably mounted for rotation in the main body portion 12, the shaft 46 being vertically spaced from the shaft 40 and extending substantially parallel thereto. An enlarged manually manipulative cylindrical knob 48 is integrally connected with the gear 44 and projects laterally from the other side thereof.

Thus, as the knob 48 is rotated in a clockwise or in a counterclockwise direction, the gear rack 30 reciprocates to the left or right (using FIGURE 2 as a referral point).

The upper end of the main body portion 12 is provided with a circumferential groove 50 which rotatably receives an inturned radial flange 52 of a cap 54 which extends across the upper end of the main body portion 12.

As is seen in the drawings, the lower end of the rod 21 terminates above the lower ends of the standards 22 to provide a substantially rectangular passage 56 through which extends the pointed end 58 of a non-rotatable pivot pin 60, the other end of which is fixedly secured, by conventional means, to the lower end of the rod 21.

The rack gear 30 has a centrally positioned axially extending passageway 62 formed therein which is adapted to receive for reciprocation therethrough an elongated length of flexible wire 64 of which that portion 66 thereof which projects beyond the rack gear 30 adjacent the jam tooth 36 will be hereinafter referred to as the beam. As will become more apparent as this specification progresses, a substantially rigid solid rod (not shown) may be substituted for the wire 64. A set screw 68 is threaded through the rack gear 30 to engage the wire 64 in order to fixedly hold the beam portion 66 in its adjusted position.

In FIGURES 1, 2 and 5, it is seen that the outer end of the beam 66 has an enlarged cylindrical head 7 0 which is releasably secured within the hollow boss 72 by means of a set screw 74. The boss 72 is integral with and projects laterally from the upper end of an inverted substantially hollow frusto-conical housing '76 having opposed open ends. From the drawings it is also seen that a plurality of radially spaced stabilizing standards 78 project laterally from the housing 76, the lower ends of the standards engaging the support surface 24 to maintain the housing in a substantially upright position.

An inverted open ended substantially hollow frusto conical member 80 is inserted in and nests against the inner side of the housing 76. The base of the member 80 is formed with a radial flange 82 that abuts against the base end of the housing 76 and the other end of the flange 84. As is seen in FIGURE 2, the liner 80 is formed with a plurality of longitudinally extending, spaced and inwardly projecting ribs 88'. v The liner 80 is adapted to receive a conventional lead pencil '90 with the pointed end 92 thereof adapted for engagement with the support surface 214, the lead pencil'90 being indicated by phantom 1 To utilize the beam type compass described above,

the draftsman places the pen point 58 over the center point of the circle or are 94- (see FIGURE 1) to be drawn. The operator holds the cap 54 with one hand and with the other hand moves the housing 76 away from the rack gear 30 thereby extending the beam 66. This movement is continued until the distance between the point 58 and the pencil point 921 is slightly greater than the desired radius of the circle or arc 94 to be traced or inscribed. Thereafter, the operator tightens the set screw 68 against the wire 64 and then rotates the knob 48 in a clockwise direction to effect movement of the rack gear 30 towards the left (reference now being made to FIGURE 2) to obtain the precise desired radius. The operator then traces the desired curve, are

or circle. In moving the housing 76 and pencil 94- arcuately it will be understood thatthe cap 5'4, flange 20 and stabilizing standards 22 remain stationary while the main body 12 and rack gear 30are free to rotate.

If desired, amechanical pencil could be incorporated withv the housing 76.

Having described and. illustrated one embodiment of this invention in detail, it will be understood that the same has been offered merely by way of example, and that the instant invention is to be limited only by the scope of the appended claims.

What is claimed is:

1. A beam compass comprising a relatively stationary base, a pedestal mounted for rotation on the axis of and upstanding from said base, said base having a centering pin for engaging a drawing surface, said pedestal having a radial bore extending therethrough, a rack bar slidably supported through said bore, said rack bar having longitudinally spaced teeth on a side thereof, said pedestal having an internal recess opening to said radial bore, a worm located in said recess and meshed with the rack bar teeth, said worm having a shaft journaled through the pedestal and having thereon a pinion outside of the pedestal, a gear wheel journaled on the pedestal parallel to the worm shaft and meshed with said pinion, a rotating knob secured to said gear wheel, a hand grip cap rotatably mounted on the upper end of the pedestal, said rack bar having an outer end and a longitudinal bore extending to said outer end, a beam having an inner end portion slidably engaged in said longitudinal bore and an outer end portion extending beyond the outer end of the rack bar, means for locking the beam in longitudinally adjusted positions in the rack bar, and drawing surface engaging scriber housing means connected to and depending from the outer end portion of the beam.

2. A beam compass comprising a relatively stationary base, a pedestal mounted for rotation on the axis of and upstanding from said base, said base having a centering pin for engaging a drawing surface, said pedestal having a radial bore extending therethrough, a rack bar slidably supported through said bore, said rack bar having longitudinally spaced teeth on a side thereof, said pedestal having an internal recess opening to said radial bore, a worm located in said recess and meshed with the rack bar teeth, said worm having a shaft journaled through the pedestal and having thereon a pinion outside of the pedestal, a gear wheel journaled on the pedestal parallel to the worm shaft and meshed with said pinion, a rotating knob secured to said gear wheel, a hand grip cap rotatably mounted on the upper end of the pedestal, said rack bar having an outer end and a longitudinal bore extending to said outer end, a beam having an inner end portion slidably engaged in said longitudinal bore and an outer end portion extending beyond the outer end of the rack bar, means for locking the beam in longitudinally adjusted positions in the rack bar, and drawing surface engaging scriber housing means connected to and depending from the outer end portion of the beam, said housing means comprising a vertical tubular housing having open upper and lower ends, lateral feet on said housing and extending below said lower end to engage a drawing surface, a scriber receiving liner secured in the housing.

3. A beam compass comprising a relatively stationary base, a pedestal mounted for rotation on the axis of and upstanding from said base, said base having a centering pin for engaging a drawing surface, said pedestal having a radial bore extending therethrough, a rack bar slidably supported through said bore, said rack bar having longitudinally spaced teeth on a side thereof, said pedestal having an internal recess opening to said radial bore, a worm located in said recess and meshed with the rack bar teeth, said worm having a shaft journaled through the pedestal and having thereon a outside of the pedestal, a gear Wheel journaled on the pedestal parallel parallel to the worm shaft and meshed with said pinion, a rotating knob secured to said gear wheel, a hand grip cap rotatably mounted on the upper end of the pedestal, said rack bar having an outer end and a longitudinal bore extending to said outer end, a beam having an inner end portion slidably engaged in said longitudinal bore and an outer end portion extending beyond the outer end of the rack bar, means for locking the beam in longitudinally adjusted positions in the rack bar, and drawing surface engaging scriber housing means connected to and depending from the outer end portion of the beam, said housing means comprising a vertical tubular housing having open upper and lower ends, lateral feet on said housing and extending below said lower end to engage a drawing surface, a scriber receiving liner secured in the housing, said housing having a lateral boss thereon having a fluid bore in which the outer end of the beam is removably engaged, and means securing the beam in place in said fluid bore.

References Cited in the file of this patent UNITED STATES PATENTS 336,868 Pratt Feb. 23, 1886 601,455 Wildman et a1 Mar. 29, 1898 811,237 Merritt Jan. 30, 1906 992,819 Springer May 23, 1911 1,005,827 Gombarts Oct. 17, 1911 1,304,501 Menin et a1. May 20, 1919 1,948,952. Wallerius Feb. 27, 1934 2,296,279 Hamilton Sept. 22, 1942 2,324,041 Suverkop July 13, 1943 2,523,237 Richardson Sept. 19, 1950 2,556,240 Valentine et al June 12, 1951 2,607,990 Payamps ...1 Aug. 26, 1952 FOREIGN PATENTS 5,809 Great Britain 1898 6,306 Great Britain 1899 116,118 Germany Dec. 28, 1900 589,174 Great Britain June 12, 1947 OTHER REFERENCES Popular Mechanics magazine, July 1945, page 139. (Copy in 33-270.)