US2532376A - Beam trammel - Google Patents

Description

Dec. 5, 1950 R. SMITH 2,532,376

BEAM TBAMMEL Filed Jan. 9, 1947 Inventor Robert Smith By 9mm WWW Patented Dec. 5, 1950 UNITED STATES PATENT OFFICE 9 Claims.

The present invention relates to new and useful improvements in trammels and more particularly to a trammel head embodying means to facilitate the adjustment of the needle on the trammel bar.

An important object of the present invention is to provide a trammel head embodying means for locking the head in longitudinally adjusted position on the trammel bar by a rotary movement of the needle.

More specifically, the invention embodies locking means for the trammel head operated by a camming action upon a rotary movement of the needle in the head.

Another object of the invention is to improve the construction of the head to facilitate mounting of the needle and head on the trammel bar.

A still further object is to provide a device of this character of simple and practical construction, which is efficient and reliable in operation, relatively inexpensive to manufacture and otherwise well adapted for the purposes for which the same is intended.

Other objects and advantages reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure 1 is a side elevational view of the trammel with one of the heads shown in section.

Figure 2 is a sectional View taken on a line 2-2 of Figure 1.

Figure 3 is a sectional view taken on a line 33 of Figure 2.

Figure 4 is a transverse sectional view through the head taken on a line 44 of Figure 1.

Figure 5 is a side elevational View of one of the heads with the manipulating knob for the needle shown in section.

Figure 6 is a perspective view of a modified head construction, and

Figure '7 is a similar view of a further modification thereof.

Referring now to the drawings in detail and first with respect to the form of invention illustrated in Figures 1 to 5 inclusive, the numeral 5 designates a trammel bar on which a pair of trammel heads 6 and 1 are slidably mounted. The bar 5 is of cylindrical shape and is formed with a flat side 8.

Each of the heads 6 and I are of duplicate construction and accordingly a detailed explanation of one will suifice for both. The head comprises a box-like frame open at its front and rear ends and is formed with its top and bottom walls parallel and having aligned openings 9 in which the cylindrical needle 10 is inserted. The sides of the head are also formed with aligned openings II in which the trammel bar 5 is slidably received.

A collar I2 is suitably secured to the lower portion of the needle under the head 6 and the upper end of the needle is provided with a manipulating knob I3.

The lower end of the needle is bevelled as shown at !4 to provide an eccentric point l5 at one side of the needle and a portion of the needle positioned in the head 6 is flattened as shown at l6 for movement into and out of confronting position with respect to the fiat side 8 of the trammel bar 5.

In the operation of the device, the needle I0 may be freely rotated in the head 6 and when the flattened side 8 of the trammel bar 5 and the flattened side "5 of the needle are moved into confronting relation the head 6 is free to slide 1ongitudinally of the bar 5, to adjust the head into a desired position. By rotating the needle I0 the rounded sides thereof will work against the flattened side 8 of the trammel bar in a camming action to bind the needle against the bar and thus lock the head in its adjusted position thereon.

As illustrated in Figure 5 of the drawings, the portion of the needle immediately above and below the trammel bar 5 may be formed with circumferential grooves I! to weaken the needle and thus provide greater resiliency therein at its point of locking engagement to increase the binding action thereof with the trammel bar.

In Figures 6 and 7 of the drawings, I have illustrated modifications in the head construction, the head I8 in Figure 6 being of U-shaped construction positioned horizontally and with aligned openings l9 formed in its upper and lower ends for receiving the needle. The vertical wall of the head at its inner surface is formed with a horizontal raised groove 2 in which the trammel bar is positioned.

In Figure 7, the U-shaped head is shown at 21 which is also formed with the horizontal raised groove 22 on the inner surface of its vertical wall and the vertical Wall is also formed with a vertical slot 23 and which also extends forwardly into the top and bottom edges of the head to form upper and lower slots 24 for receiving the needle. The needle is assembled in the head ill by sliding the needle forwardly through the vertical wall 2| to the front end of the slot 24 and the trammel bar is then positioned in the groove 22 be hind the needle.

ably mounted onthe. her said In view of the foregoing description taken in conjunction with the accompanying drawings it is believed that a clear understanding of the construction, operation and advantages of the device Will be quite apparent to those skilled in this art. A more detailed description is accordingly deemed unnecessary.

It is to be understood, however, that even though there is herein shown and described a preferredlembodiment, of the invention the same is susceptible to certain changes fully comprehended by the spirit of the invention as herein described and the scope of the appended claims.

I claim:

1. A trammel comprising a cylindrical bar having a flattened side, a head slidably mounted on the bar said head being of, open frame, con struction and including at least a pair of parallel walls, a rod rotatably mounted in the parallel walls of the head at right angles to the bar, said rod projecting vertically through the head and having amanipulating handle at its upper end and a pointed lower work contacting end, said rod being cylindrical and haying a: it ned side for confronting arrangement with the flattened side of the car; and said rod earnming, against the bar upon rotation of the rod to move its rounded side into engagement. with the flattened side of the bar.

2. A trammel comprising a bar, a head slidably mounted on the bar said head being of open frame construction and including at least a pair of parallel walls, a rigid pointed rod rotatahiy mounted in the parallel walls of the head at right. angles to. the bar, and a resilient cam car ried by the rod for movement into and out of clamping engagement with the bar to hold the head adjusted position on the bar upon a predetermined rotary movement, of the rod.

3; A, trammel comprising a bar, a head slidably mounted on the bar said head being of open firame: construction and including at least a pair of parallel walls, a rigid pointed rod rotatably inoun-ted in the parallel walls of the head at righit'anglesto the bar, and a. resilient cam meniberintegrat with the rod for iii-ding against the bar to; secure the head in adjustedv position on the bar upona. predetermined rotary nzrovementw of the rod.

4;. A trammel comprising a b a head slid lea ing of open frame construction and including at least a pair of parallel walls, a rigid pointed rod rotatably mounted in the; parallel walls: of the head at right angles to the bar, and a resilient cam built in. the rod intermediate its. ends for binding against the bar to secure the head in adjusted position on the bar upon a predetermined rotary movement of the rod.

5. A trammel comprising a U-shaped head, a (30 pointed rod rotatably mounted in the sides of the head, a grooved seat on the bight portion of the head extending at right angles to the rod, a bar positioned in the seat for slidably supporting the head, and camming means between the rod and bar to bind the rod against the bar upon a predetermined rotary movement of the rod to hold the bar in the seat and to secure the head in adjusted position on the bar.

6. A trammel comprising a U-shaped head having slots in its parallel side portions extending continuously throughout the bight, portion of the head, a grooved seat on the bight portion of the head, a bar positioned in the seat, a rod rotatably mounted in said slots, and a camming formation on the rod engaging the bar to hold the bar in the seat and to secure the head in adjusted position on the bar.

7. A tramnrel comprising a horizontal bar, a head slidable on the bar, a vertical marking pin rotatable in the head and having an eccentric pointed lower end, and a cam on the pin having loclring engagement; with. the bar, said headbeing slidable on thebar into an approximate. adjusted position of the pin, and said pointed end of the pin being. further adjusted and locked by a rotary movement of the pin.

A. trammel comprising a horizontal bar, a head slidable on the bar, a vertical marking pin rotatable in, the head and having an eccentric pointed lower end, and a cam carried by the pin, said; pin having rough and fine adjustments and said can; engaging the bar to lock the head on the bar in the roughly adjusted position of the pin by an initial rotary movement of the pin and said pin being finely adjusted by a subsequent rotation of the pin.

A trammel comprising a horizontal bar, a head slidable on the bar, a vertical marking pin rotatable in the head and having an eccentric pointed lower end, and a cam on the pin engaging theibar, saidcam locking the head on thebar upon an initial, rotation of the pin, and said pointed end of the pin being adjusted upon a subsequent rotation of the pin.

ROBERT SMITH.

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

UNITED STATES PATENTS Number Name Date 307,364 Wells Oct. 28, 1884- 336,868 Pratt Feb. 23, 1386 517,696 Hunter Apr. 3, 1894; 599,765 Chase Mar. 1', 1898 661,560 Stall Nov. 13, 1900 677,339 Comstock July 2 1901 FOREEGN PATENTS Number Country Date 831,503 France June 7, 1938

Images