US2418796A - Drafting pen - Google Patents

Description

April 1947- I A. SZERENYI 2,418,796

DRAFTING PEN Filed Nov. 8, 1944 Patented Apr. 8, 1947 H 1 UNITED STATES PATENT OFFICE DRAFTING PEN Andrew Sz erenyi, Toronto, Ontario, Canada Application November 8, 1944, Serial No. 562,413

4 Claims.

. 1 This invention relates to drafting pens.

- In order to facilitate the clean ng of drafting pens, it has been proposed to hinge one of the blades of the pen in order that it maybe swung back from the other to permit ready access to the inside surface of both blades. In one known type of construction the blade is hinged but normally held in position by the adjusting screw and it is necessary to remove the adjusting screw in order to swing back the blade. In another known h nged structure, somewhat more practical, a spring member is provided along the outside of the stationary blade and so directed to engage a portion of the swingable blade normally to press it towards the other blade and adjustment is therefore effected by hearing contact of the adjusting screw on the opposite blade, operating against the spring pressure, while the blade can be forcibly swung open against this spring pressure when it is desired to clean the blades.

The second structure has advantages over the first as it does not require the removal of the thumb screw to swing the blades apart for cleaning purposes. However, it has other disadvantages in that the spring structure disposed on the outside of the stationary blade is cumbersome in use and is costly.

The advantages of this type of pen can be provided while avoiding the disadvantages, and it is a main obect of the present invention to provide a drafting pen having a swingable blade spring pressed to normal position by means of a simple spring structure that is held within the confines of the shank portion of the pen.

A further object of the invention is to provide a pen of this character wherein the springis socketed within the handle of the pen and may be removed or replaced readily in the ordinary manner of dismantling a pen.

A still further object of the invention is to pro-.

vide a pen of this character employing a very simple spring structure.

A still further object of the invention is to provide a pen which can provide these advantages and which can be manufactured at a comparatively low cost. -With these and other objects in view, the invention generally comprises a pen having opposed relatively adjustable blades, one of which is pivotally mountable and swingable to displace it toia substantial degree from the other blade, said swingable blade being normally spring pressed into engagement with or in close proximity to the other blade including a simple spring member housed within the shank of the pen and normally pressing an end of the swingable blade beyond the pivot point, ..Preferably, the spring 2 is a simple leaf spring housed within the shank portion and socketed in the end of the handle.

The invention will be clearly understood by reference to the following detailed specification taken in conjunction with the accompanying drawings.

In the drawings,

Figure 1 is a side elevation of a drafting pen with the handle portion shown fragmentarily.

Figure 2 is an enlarged sectional fragmentary view of a part of a drafting pen illustrating the general relation of the cooperating parts according to the present invention.

Figure 3 is a similar view to Figure 2, the section being taken at degrees to that of Figure 2.

Figure 4 is a section taken on the line 4-4 of Figure 2.

Figure 5 is a fragmentary side elevation of a pen according to the present invention taken at 90 degrees to the showing in Figure 1 and illustrating the use of a slot in the shank portion of the pen. Figure 6 is a perspective detail of a preferred structure including a mounting member therefor.

Referring to the drawings, A indicates a drafting pen which may be a ruling pen or the pen portion of a compass, a ruling pen being described and illustrated in the present application. The pen includes a shank portion ll! carrying the pen unit H and handle I2. The pen unit l! is comprised by the blades l3 and Hi, the latter blade being pivotally mounted as at l5 and conse uently is swingable from the blade 13 to a substantial degree where it is desired to separate the blades for cleaning purposes. The blade I4 is spring urged towards the blade I3 and normal adjustment is effected by the adjusting screw it, screw threaded in the blade l4, and in bearing contact with the blade l3.

According to the present invention the pen unit l l is slotted as at i! to permit the inner end is of the blade M to swing as the blade pivots about its pivotal points and the penunit is formed with the screw-threaded connector portion provided'by the arms iii and 2t extending-parallel to one another and separated by the slot ll, the outer surfaces of the arms is and 28 being SCIEW-t threaded as indicated at 2i. These are designed to fit in threaded engagement with a screwthreaded portion 22 of the bore 23 of the shank member If). The slot l'i preferably extends up wards from a bore lla in the pen unit. This bore reduces any binding tendencies between the corners of the inner end it of blade Hi and the slot as the blade is pivoted and facilitates the milling of the slot. The butt of end l8: of blade M has a'fiat surface designed to abut the spring 28 when the blade is in an open position. The opposite end of the bore 23 is partially screwthreaded as at 24 to engage with the screwthreaded nipple portion 25 of the handle 12, the said nipple portion, according to the preferred form of this invention, being formed with a socket 26,

Within the bore 23 the anchoring member 21 of the leaf spring 28 is normally positioned, The anchoring member, at one end, preferably embeds or suitably secures one end of the spring 28 and preferably also has an integral sooketing pin 29 projecting from its other end which is designed to fit within the socket 26 of the nipple 25. When so assembled the spring 28 passes through the slot I! and is disposed in bearing engagement with the inner end Id of the blade [5. Thus, it; urges this blade into contact with the blade l3 from which it may be separated in normal use by the adusting screw It. When, however, it is desired to separate blade M from blade I3 to a substantial extent, such as for cleaning purposes, it is only necessary to pull outwardly upon the blade M which will then pivot against the pressure of the spring 23 until, if desired, the butt of end l8 may be caused to lie parallel to and in. abutting engagement with spring 28. The blade is readily returned to normal position merely by swinging it back that way and the spring will automatically return it when it has been swung to a sufficient extent.

Thus, by simple construction which merely in-- volves four essential parts, viz., the pen unit H, the shank Ill, the spring unit and the handle, a simple operated pen is provided in which the swingable blade is spring pressed from within the confines of the pen structure. Moreover, the pen may be readily dismantled merely by unscrewing the shank from the handle 12 when the spring unit may be removed while the pen unit then may be separated from the shank merely by unscrewing it from the latter.

The leaf spring may be merely a single leaf spring or may be provided with a suitable reinforcing leaf 28 as illustrated. Moreover, it may be bent in any suitable manner efiiciently to co-- operate with the movable blade It. It should be noted that the sleeve-like shank portion ill of the pen may be slotted as at Ili (see Figure which slot is al gned with the slot ll of the pen unit so that in a small or narrow type of pen sufiicient space is provided to permit the spring to move in a practical manner.

The invention is of course subject to variation of construction within the princ ple illustrated and it will be apparent that the simple construction disclosed, while permitting ready adjustment of the swingable blade to the stationary blade,

eliminates protruding spring means for urging the blades together which spr ng means would normally be cumbersome during use.

What I claim as my inventionis:

1. A drafting pen comprising a pen unit having a shank portion slottedat its inner end, a stationary blade integral with said shank portion of said pen un t, and a movable blade pivotally mounted to said shank portion so that a portion of said movable blade above said pivot point is swingable within said slot, said pen unit being normally carried by a handle, means for detachably connecting said unit to the handle, including a sleeve-like shank having internal screw threading to receive said handle at one end, said pen unit having a pair of externally screw- 4 threaded but spaced apart anns projecting therefrom designed to enter the opposite end of said shank, the spacing between said arms forming a continuation of said slot, spring means housed within said shank and extending into said slot, said means engaging a portion of said movable blade and normally urging the latter towards the stationary blade and an adjusting screw carried by oneof said blades movable into bearing engagement with the other of said blades for separating the blades one from the other against the pressure of said spring means.

2. A drafting pen comprising a pen unit having a shank portion slotted at its inner end, a stationary blade integral with said shank portion of said pen unit and a movable blade pivotally mounted to said shank portion so that a portion of said movable blade is disposed within said slot, a handle, a bifurcated screw-threaded shank in connection withsaid unit and a sleeve for detacnably connecting it with said handle said bifurcated portion forming a continuation of said slot, a socket. formed in the end of the handle, spring means anchored in said socket including a shank insertable in said socket having a leaf spring depending therefrom, the latter projecting into the slot of said unit, and into pressure engagement with said portion of the movable blade, said spring means normally urging said movable blade towards the stationary blade and an adusting. screw carried by one of said blades movable into bearing engagement with the other of said blades for separating the blades one from the other against the pressure of said spring means.

3. A drafting pen as claimed in claim 1 in which the end of the handle is formed with a socket communicating with the interior of said sleeve, said spring means including a shank designed detachably to fit within the socket of said handle, said shank extending into said sleeve and designed to connect with said spring means to hold said spring means in operative engagement with said blade of the pen unit.

4. A drafting pen as claimed in claim I in which the end of the handle is formed with a socket communicating with the interior of said sleeve, the hollow interior of the sleeve being or greater diameter than the diameter of said socket, said spring means including a shank formed with an enlarged and a reduced end portion, the latter detachably fitting within the socket of the handle, the enlarged portion of the shank being held within the enlarged interior of said sleeve, a shoulder formed between the enlarged portion of the reduced portion of said shank, said shoulder normally abutting the end of said handle adjacent to said socket, said shank having a leaf spring depending therefrom into the slot of the pen unit to engage said portion of the movable blade.

ANDREW SZERENYI.

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

UNITED STATES PATENTS Number Name Date 684.437 Keufiel Oct. 15, 1901 480,541 Alteneder Aug. 9., 1892 1,333,129 Pease Mar, 9, 1920 1,344,045 Kleuver June 22, 1920. 1,421,455 Green July l, 1922 1,452,576 Thomas Ap.r 2.4.1923

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