US2419752A

US2419752A - Beam compass

Info

Publication number: US2419752A
Application number: US547460A
Authority: US
Inventors: Gottfried F Zumbuhl
Original assignee: Individual
Current assignee: Individual
Priority date: 1944-07-31
Filing date: 1944-07-31
Publication date: 1947-04-29
Anticipated expiration: 1964-04-29

Description

G. F. ZUMBUHL 2,419,752

BEAM COMPASS Filed July 31. 1944 My 2 H5 1 mm 2% r D MM my T w 6 April 29, 1947.

Patented Apr. 29, 1947 UNID STATES PATENT OFFICE 1 Claim.

The present invention relates to-improvements in a beam compass, and it consists of the combinations, constructions and arrangements hereinafter described and claimed.

An object of my invention is to provide a beam compass in which the bar is formed of two hinged members thus permitting the bar to be folded into a compact size when not used.

A further object of my invention is to provide a novel center point and an inscribing member for the beam compass, both of these being adjustable along the bar into the desired positions. The bodies of the center point and the inscribing member are preferably made of a transparent material such as plastic and therefore do not hide the scale markings on the bar.

A further object of my invention is to provide a device of the type described in which the center point and the inscribing member have novel clamping means for securing the members to the beam at the desired places.

Other objects and advantages will appear in the following specification, and the novel features of the device will be particularly pointed out in the appended claim.

My invention is illustrated in the accompanying drawing forming a part of this application, in which:

Figure 1 is a side view of the beam showing the center point and inscribing member partially in section;

Figure 2 is a side elevation of a portion of the clamping means; and

Figure 3 is a transverse section taken along the line 3-3 of Figure 1.

While I have shown only the preferred form of my invention, it should be understood that various changes or modifications may be made within the scope of the appended claim without departing from the spirit and scope of the invention.

In carrying out my invention I provide a bar indicated generally at A and this bar may be of any length desired. I have shown it as having a length of twenty four inches with a pivot point I at the twelve inch mark so that the two

arms

2 and 3 of the bar may be swung about the pivot into alignment with each other as shown in Figure 1 or into overlapping relation when the device is not used. The pivoted bar is preferably made of metal and is relatively thin, as shown in Figure 3. I have used a Lufkin rule for the bar and the

arms

2 and 3 of the rule have stops 4 that abut each other when the two 2 arms are opened into the position shown in Figure 1.

On the beam or bar I adjustabl mount a center point, indicated generally at B; and an inscribing member, indicated generally at 0.

Both the devices 3- and C are identical in construction, except-that the center point B carries a pointed steel pin 5 while .the inscribing member carries a pencil or a soapstone 6. I will describe the member B in detail and this will sufiice for both the members B and C except Where the member C differs slightly from the structure of the member 3.

A body 1, preferably transparent and hollow, has slots 8 for slidably receiving the beam A. I have shown the body 1 bullet-shaped, although I do not Wish to be confined to this particular design. The pointed end 9 of the body l carries the pin 5 and the opposite end has a metal sleeve with a threaded [bore 90.. There are two slots 8 in the body and the length of the slots is equivalent to the height of the beam.

A clamping cap I!) or sleeve is slidably mounted on the outer surface of the body 1. The cap is preferably made of transparent material and. carries a centrally disposed screw I! that is designed to be threaded into the bore 9. The head of the screw is embedded in the cap. Figure 2 shows the cap I 0 provided with an enlarged knurled portion I2 and a rounded head I3 at the end of the cap. The cap rim M is designed to engage frictionally with the edge l5 of the rule or beam when the cap is screwed down into place. The cap can be rotated manually by gripping the knurled portion l2. The cap rim binds the body I to the beam.

The body 1 is transparent and a marker l6, such as an arrow is placed on the body and is in line with the point 5 so that when the marker is brought into registry with the desired mark on the scale ii, the operator will know that the point 5 is in line with the mark. The center point B may be adjusted along the arm 2 and then clamped in position. It is obvious that the center point B may be placed on the arm 3 if desired.

The inscribing member is constructed in identically the same manner as the member B except that the body 1 has a bore 18 for receiving the pencil 6 or a piece of soapstone. Any marking member may be placed in the bore 58. The inscribing member will have its similar parts provided with like reference numerals and a further description of it need not be given. The member C may be moved along the arm 3 of the beam A or it may be moved along the arm 2. The inscribing member is clamped in position by rotating the cap It].

From the foregoing description of the various parts of the device, the operation thereof may be readily understood.

If a large circle is to be inscribed, the member B is placed on one arm and the member C placed on the other. The scale H on the beam permits the operator to adjust the distance between the point 5 and the pencil 6 to equal the desired radius. The beam pivot point I will not interfere with the use of the beam because the members B and C can be moved closer to the pivot point I if desired or both members may be placed on either arm. It is also possible to swing the arm 3 into a right angle position with respect members B and C are both placed on the arm 2 and in this way the arm 3 can act as a handle for moving the inscribing instrument about the center point.

It is also possible to use the device as a caliper because when the arms 2 and -3 are swung into an angular position with respect to each other, the point 5 and the point of the pencil 6 may be used to contact the piece being measured and then the distance between the two points 5 and 6 may be determined after the instrument is removed from the measured piece. The device is extremely simple in construction and is durable and eflicient for the purpose intended.

I claim:

In a device of the type described, a transparent hollow cylindrical body having longitudinally extending slots in the cylindrical wall for receiving a bar with a scale thereon, said body having a point at one end and a threaded =bore at the other, a cap slidable on the body and having a screw adapted to enter the threaded bore, whereby a turning of the cap will cause the screw to move the cap rim into clamping engagement with the bar.

GOTTFRIED F. ZUMBUHL.

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

UNITED STATES PATENTS in the