US2621412A

US2621412A - Beam compass construction

Info

Publication number: US2621412A
Application number: US146322A
Authority: US
Inventors: Jr Harley J Slusher
Original assignee: Individual
Current assignee: Individual
Priority date: 1950-02-25
Filing date: 1950-02-25
Publication date: 1952-12-16
Anticipated expiration: 1969-12-16

Description

IN VEN TOR. Hfl/FLEY J kilususe, r/fl,

( zI/I/Ill H. J. SLUSHER, JR

BEAM COMPASS CONSTRUCTION Filed Feb. 25, 1950 Dec. 16,1952

Y Z AT'roRNEYs.

Patented Dec. 16, 1952 --UNITED STATES PATENT OFFICE f 2,621,412.11. f I BEAM-COMPASS CONSTRUCTION Harley J. Slusher, .112; Glendale, Ohio Application Fcbruary 25,1950, Serial No. 146,322

My invention relates to beamc'ompass or tram- .mel construction. and, parti cularly21 the adjustable socket pieces thereof. H V f r In the art the typical beam compass .consists of a round bar with adjustable socket pieces having heads with openings extending through the heads which slidably fit on the round bar. Thumb nuts are provided for tightening the head on the bar. Slotted couplings having a threaded cap receive the lead or pins necessary foruse of the compass. Such compasses fail for accuracy in that the heads turn on the bar during use leading to inaccuracies in layout work.

It is the object of my invention to provide novel types of socket pieces with which a draftsman can, with a piece of cold rolled steel bar stock from the stock room make himself a beam compass having a desired span. 7

In my socket pieces by my particular combination of elements it is my object to provide a beam compass which, when the socket pieces are adjusted in holding position will be substantially rigid so that the space between the center point and the drawing point will remain substantially exact with no disalignment of preset distances due to rocking of one socket piece or the other.

The foregoing objects and other objects in simplicity of construction and accuracy I accomplish by that certain combination and arrangement of parts of which I have illustrated a bodiment.

Referring to the drawings:

Figure l is a side elevation of a beam compass constructed in accordance with my invention.

Figure 2 is a section along the lines 22 of Figure 1 on a larger scale. v

Figure 3 is a section through, a socket piece along the lines 3-3 of Figure 1, also on a larger scale. '1

Figure 4 is a sectional view of the parts shown in Figure 3 disassembled.

Figure 5 is a perspective view of the socket head piece.

As I have explained, the socket pieces are designed for being mounted on a rectangular piece of cold rolled stock. Thus in Figure 1"I have shown such a piece. The draftsman need only go to the shop and select a piece of desiredllength be it one foot or six feet for example. 'Presumably the socket pieces will be made of such size as to fit standard size of rectangular cold rolled stock such as inches thick and inches wide.

While I contemplate the selection by the draftsman of bar stock of appropriate length, it will, of

course, be entirely feasible to provide a piece of cold rolled bar stock with the socket pieces alpreferred em sired, be of wood or plastic.

The important, elements of the combination lie in the socket pieces which are of identical construction as far as their mounting and adjustment features are concerned.

The socket pieces are formed with heads 2 having slotted point receiving extensions 3 with threaded caps 4 which engage the external threads of the extension and tighten down clamping the slotted sides of the extension together and securing the lead or steel tip indicated at 5 in position. Such tip receiving ends are conventional in compasses.

The heads 2 are tapped out as indicated at 6 and threaded with internal threads as indicated at 1, which engage the thumb screw 8 having matching threads 9. The thumb screw has an annular flange or collar Ill. The under surface of the collar bears against a cap I I having inner cylindrical walls l2 which fit snugly but slidably over the outer walls of the heads.

A slot I3 is cut lengthwise through the head and the dimensions as to width and bottom are such that the piece I of cold rolled bar stock engages the inner walls of the slot fairly snugly but with a sliding fit. When the thumb screw, which passes through a hole H in the center of the cap is tightened down, its end does not engage the top wall of the bar stock. There is always a space as indicated at IS in Figure 3. Instead the annular lower edge l6 of the collar bears against the top surface of the bar stock. This is an important element of the combination. It will be noted that as the cap is forced down to bear ready on it. Also the bar or beam may, i f de-j against the bar-stock it has bearing against the bar on both sides where the bar emerges from the slot in the head. Thus there are spaced frictional bearing areas which prevent the socket pieces from rocking lengthwise of the bar. Further the use of bar stock arranged endways makes a rigid mounting bar or beam.

In the use of beam compasses the distance a part of the tips is made by accurate measurement- Once this distance is deter between the tips. mined, the tips are held rigidly in place. Since the adjustment of the socket pieces on the bar or beam does not gouge into the metal as would any kind of adjustment screw, the socket pieces always slide easily so that there are no working 3 claim as new and desire to secure by Letters Patent is:

In a socket piece for a beam compass having a beam which is rectangular in cross section, an elongated cylindrical body having a tip receiving extension on the bottom end thereof, said cylindrical body being slotted longitudinally thereof to provide a rectangular channel opening upwardly through-the top of said body to snugly but slidably receive a rectangular beam arranged edgewise theiein, said slotted portion having a depth greater than the depth of the rectangular beam, said cylindrical body having a centrally disposed longitudinally extending internally threaded bore at the upper end of said slotted portion, an annui lar cap member fitted snugly but slidably over the head of said body member, saidl cap memberhaving a centrally disposed opening in the top thereof, an adjustment screw passing through the opening" in said cap and having threads engaging said internally threaded bore; said a screw having an integral collar for engagement with thertop of said cap, said cap being of a ,depth greater than the distancebetween the upper sur- 7 face of the beam and the top or said cylindrical body when the beam is fitted in said slotted portion, whereby the lower annular edge of said'cap will bear against the upper surface of the beam on each side of said slotted porton to provide spaced clamping points preventing movement of the rectangular beam relative to the cylindrical body of the socket piece.

HARLEY J. srlUsH aJR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 2&02'0 Austria Jnly 26, 1909