US2581538A

US2581538A - Extension beam drafting instrument

Info

Publication number: US2581538A
Application number: US736825A
Authority: US
Inventors: Joseph F Joy
Original assignee: Joy Manufacturing Co
Current assignee: Joy Manufacturing Co
Priority date: 1947-03-24
Filing date: 1947-03-24
Publication date: 1952-01-08
Anticipated expiration: 1969-01-08

Description

Jan; 8, 1952 J. F. JOY

EXTENSION BEAM DRAFTLNG INSTRUMENT Filed March 24, 1947 WIN Patented Jan. 8, 1952 EXTENSION BEAM DRAFTIN G INSTRUMENT Joseph F. Joy, Pittsburgh, Pa., assigner to Joy Manufacturing Company, Pittsburgh, Pa., a corporation of Pennsylvania Application March 24, 1947, Serial No. 736,825

4c Claims. (Cl. 33--158) This invention relates to drawing instruments and more particularly to an improved extension beam compass of a relatively simple construction having a wide range of adjustment, thereby increasing the usefulness of the instrument.

In the extension beam Compasses of known designs, there are usually provided telescopically arranged, relatively slidable beam sections, one section having a point holder carried at its outer extremity and the other section having slidable` thereon and adjustable relative thereto a holder for a drawing element or divider needle. By sliding the holder of the drawing element or divider needle along itsv beam section, it may be brought relatively close to the point holder, and by fully extending the beam sections and sliding the drawing element or divider needle holder to the outer extremity of its beam section, the holders may be widely spaced. ln one known construction, the telescopically arranged beam sections are separable, and when it is desired to obtain a wide adjustment of the pointers or drawing elements, it is necessary to remove one beam section, turn it end for end, and reinsert it in its reversed position on the other beam section. The present invention contemplates an improvement over known types of beam compasses in that the -te-lescopically arranged, relatively slidable beam sections have permanently secured to their opposite extremities holders for the point and drawing element or divider needle so that independent slidable adjustment of one holder along its beam section together with the special adjusting and setting means therefor, are avoided and adjustment of the pointers between zero and maximum positions areeffecte'd simply by relatively extending the beam sections. Accordingly, the

structure of the present invention is simplified,

and special sliding holders and their adjusting and setting means and the necessity of taking the beam sections apart are completely elimihated.

It is an object of the present invention to provide an improved drawing instrument having an increased range of usefulness. Another object is to provide an improved extension beam compass having improved. structural features whereby simplicity and ease of adjustment are' attained. A further object is to provide an improved. extension. beam compass having telescopically arranged, relatively slidable beam sections, each section having a holder permanently secured thereto at its outer end and so arranged and constructed that the holders may be brought close ingentes or moved wide apart simply by adjusting the beam sections. Yet anotherbbject is to provide an improved extension beam compass having improved telescopic beam sections whereby the ends of the beam sections, which are most remote when the beam sections are fully extended, may be brought relatively close together When the beam sections are in their eX- treme opposite adjusted position. A still further object is to provide an improved extension beam compass comprising telescopically arranged, relatively slidable beam sections of an improved design whereby the ends of the beam sections, which are most remote when the beam sections are in maximum extended position, carry holders for the point and drawing or divider needle elements, and so arranged and constructed that the remote ends, upon telescoping of the sections, may be located so that the holders are brought together in abutting relation with the point and drawing or divider needle elements at zero position. Yet another object is to provide an improved extension beam compass which, by a simple sliding movement, may be readily adjusted from zero position to its maximum extended position. Other objects and advantages of the invention will, however, hereinafter more fully appear.

In the accompanying drawing there is shown for purposes of illustration one form which the invention may assume in practice.

In this dra-Wing:

Fig. 1 is -a top plan View of a beam compass constructed in accordance with an illustrative embodiment of the invention, with the beam sections fully extended to locate the holders wide apart.

Fig. 2 is a side elevational view of the beam compass shown in Fig. l.

Figs. 3 and 4 are, respectively, top plan and side elevational views of the compass shown in Figs. 1 and 2, with the beam sections in their extreme opposite telescoped position to locate the holders close together.

Fig. 5 is an enlarged longitudinal vertical sectional view taken on line 5-5 of Fig. l.

Figs. 6 and '7 are cross-sectional views taken on lines 6--6 and 1--1 of Fig. 5.

Fig. 8 is a vertical sectional View taken on line 8-8 of Fig. 2.

Fig. 9 is an enlarged cross-sectional Viewv taken on line 9-9 of Fig. 4.

Fig. 10 is a side elevational view showing the beam compass irlyfolded position, with the holderpoint and thedawine or divider needle element Eskiued in the art.

pencil, divider needle and trammel points, other readily drawn by but a simple adjustment 'ofi parts. It will be evident that features of the invention may be embodied in instruments of other types, such as a trammel for'measuring distances in machine shop work.

The improved extension beam compass is generally designated I and comprises a pair of telescopically arranged, relatively slidable, inner and outer

tubular beam sections

2 and 3 having close sliding fits whereby they may be readily extended Vor adjusted with respect to each other but with sufficient frictional resistance to retain the sectionsin adjusted positions. The beam sections are preferably of sheet metal and formed by stamping, to obtain light weight, although they -may be constructed in various other suitable manners. "While the tubular beam sections are shown of generally ovate cross section, it will be understood that cross sections of other shapes vmay be employed, if desired. Secured in any suitable manner to the remote ends'of the beam sections are

holders

4 and 5, and the holder i ,may carry an adjustable point or needle 6 while the holder 5 may carry an adjustable pen or pencil holder element I or a divider needle. ously, the relative positions of these elements to the sections may be reversed. In a trammeLsuch as is used in machine shop work, these holders are known as trammel heads for carrying trammel points, in a manner well known to those Instead of the point, pen,

known forms of work engaging elements may be employed. The point holder 4 preferably has i a sheet metal body portion 8 suitably permanently secured to the exterior of the outer beam section 3, and a point-carrying element 9 is swiveled at I0 on the bodyportion 8and is provided with a clamp Il which may be tightened by a suitable wing-screw I2. `The holder 5 for the drawing element or divider needle has a body portion l* likewise preferably formed of sheet metalr and suitably permanently secured to the inner beam Asection 2, and has a carrying-element I@ for the pencil, pen or divider needle, swiveled thereon at I5, likewise having a clamp I6 which may be tightened by a wing-screw I1. The wing-screws engage non-rotatable nuts, shown at is in Figs.

" 8 and 11, but, if desired, the nuts may be'winged and rotatable and the screws may be stationary.

`The structures of these holders, including the Yto provide a slot extending longitudinally i. throughout its length, and the body portion I3 of theholder 5 is movable Withinthis slot, as

shown in Figs. 4 and 9, during-certain positions of relative adjustment of the beam sections. The inner beam section 2 is formed with an opentop providing a slot 2| extending throughout'a major portion of'its length and openingfthrough 'one end thereof,4 land this slot is closed atv its Obvi- 4 other end at 22 as by bending the edges of the beam section after assembly of the sections so that they are close together. Secured to the exterior of the outer beam section 3 at its end opposite from its end which has the holder 4 secured thereto, is a sheet metal member 23 having an open bottom at 24 of the same width as the slot 28 (see Figs. 5 and 7). The member 23 has an inwardly bent portion 25 projecting into the upper slot 2| and engageable with the closed end vZero position as shown. v

The inner beam section 2 is provided on its top surface with parallel series of graduations, as indicated at 21 and 28, along its opposite sides, in this instance, graduated into inches and fractions thereof from one to twenty-four inches. Evidently, these graduations may be modined and the beam sections ymay be shorter or of greater lengths. One series of graduations on one side of the beam section are numbered from one to twelve, while the other series of graduations on the other side of the beam section are numbered from thirteen to twenty-four. The member 23 is formed with a sight opening 29 having an indicator such as a pointer'30 therein, the latter adapted to travel along one series of graduations at one side of the inner beam section, and the body portion 8 of the holder 4 has a similar sight opening 3lA having an indicator such as a pointer 32 therein, the latter adapted to travel along the other series of graduations at the other side of the inner beam section. Thus the position of adjustment of the beam compass may be readily determined.

yWhen the beam compass is not in use, the beam sections may be telescoped into their coextensive relation shown in Fig. 10, with the Y point-carrying element 9 and the drawing ele- Y ment or divider needle carrying element I4 swung inwardly on their swivels I0 and I5 against the Vbottom sides of the beam sections and held there by the swivel clamps.

'As a result of this invention, an improved drawing instrument is provided having'not only simplicity in construction but also a wide range of adjustment, greatly lending to the usefulness of the instrument. By telescopically arranging and constructing the beam sections in the manner disclosed, the point and drawing element or divider needle of the compass may be readily adjusted'from a zero position to the maximum extended position by a simple sliding motion and without any rearrangement or reversal of parts. By permanently securing the holders for the point and drawing element or divider needle directly to the beam sections, the necessity of separate relatively complicated slides and adjusting and ksecuring devices therefor clearly apparent to those skilled in the art.

Whilethere is in this application speciiically described one form which the invention'inay'assume in practice, it will be understood that this form of the same is shown for purposes of illustration and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In an extension beam drafting instrument, the combination comprising a pair of cooperating telescopically arranged, relatively axially adjustable, flat beam sections, the outer beam section being tubular and having a slotlike opening extending along a flat side thereof a major portion of its length, said beam sections being relatively axially adjustable between a position wherein their remote ends are spaced apart nearly the full cumulative length of said sections and a position wherein said ends are in close proximity, and work holders for drafting elements secured to said ends respectively of said beam sections between the side edges of said beam sections, said holders when in use disposed at substantially right angles to the planes of the iiat sides of said beam sections at the side of the instrument toward the work, the flat side surfaces of said beam sections being substantially parallel to the surface of the Work during normal use of the instrument, the holder secured to the inner beam section moving in said slotlike opening during a portion of the relative adjustment of said beam sections, and said drafting elements being disposable in zero position when said ends are in close proximity as aforesaid.

2. In an extension beam drafting instrument, the combination comprising a pair of cooperating telescopically arranged, relatively axially adjustable, at beam sections the outer beam section being tubular and having a slotlike opening extending along a flat side thereof a major portion of its length, said beam sections being relatively axially adjustable between a position wherein their remote ends are spaced apart nearly the full cumulative length of said sections and a position wherein said ends are in close proximity, and work holders for drafting elements secured to said ends respectively of said beam sections between the side edges of said beam sections, said holders when in use disposed at substantially right angles to the planes of said fiat sides of said beam sections at the side of the instrument toward the work, the flat side surfaces of said beam sections being substantially parallel to the surface of the Work during normal use of the instrument, the holder secured to the inner beam section moving in said slotlike opening during a portion of the relative adjustment of said beam sections, and said drafting elements being disposable in zero position when said ends are in close proximity as aforesaid, with said work holders in abutting relation.

3. In an extension beam drafting instrument, the combination comprising a pair of cooperating telescopically arranged relatively axially adjustable beam sections, the outer beam section being tubular and having a slotlike opening extending along one side thereof a major portion of its length and the inner beam section also being tubular and having a, slotlike opening extending along a major portion of its length at the opposite side thereof from the slotlike opening of said outer member, said beam sections being relatively axially adjustable between. a position wherein their remote ends are spaced apart nearly the full cumulative length of said sections and a position wherein said ends are in close proximity, a stop element on said outer beam section and projecting into said slotlike opening in said inner beam section for limiting the maximum adjusted positions of said beam sections, and work holders for drafting elements secured to said ends respectively of said beam sections, said holders when in use disposed at substantially right angles to said beam sections at the side of the instrument toward the work, the holder secured to the inner beam section moving in said slotlike opening in said outer beam section during a portion of the relative adjustment of said beam sections, said drafting elements being disposable in zero position when said ends are in close proximity as aforesaid, and said holders being movable into abutting relation to limit the extent of collapse of said beam sections.

4.-. In an extension beam drafting instrument, the combination comprising a pair of cooperating telescopically arranged relatively axially adjustable beam sections, the outer beam section being tubular and having a slotlike opening extending along a major portion of its length, said beam sections being relatively axially adjustable between a position wherein their remote ends are spaced apart nearly the full cumulative length of said sections and a position wherein said ends are in close proximity, and work holders for drafting elements secured to said ends respectively of said beam sections, the holder secured to the inner beam section moving in'said slotlike opening during a portion of the relative adjustment of said beam sections, and said holders having pivoted portions disposable when in use in positions at substantially right angles to said beam sections at the side of the instrument toward the work and foldable along the sides of said beam sections when the instrument is not in use, the ends of said pivoted portions extending into said slotlike opening against the adjacent side of the inner beam section when said holders are in folded relation.

JOSEPH F. JOY.

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

UNITED STATES PATENTS Number Name Date 370,313 Burroughs Sept. 20, 1887 695,661 Theibault Mar. 18, 1902 718,923 Ellsworth Jan. 20, 1903 916,912 Carrier Mar. 30, 1909 1,134,692 Mason Apr. 6, 1915 1,258,536 Conner y Mar. 5, 1918- 1,288,412 Hill Dec. 17, 1918 1,488,482 Eckman Apr. 1, 1924 1,617,662 Ackroyd Feb. 1.5, 1927 1,670,509 Jung May 22, 1928 2,440,973 Podolan May 4. 1948;