US2081217A - Center punch - Google Patents

Description

May 25, 1937 P. B. BOTTING. SR

CENTER PUNCH Filed Nov. 23, 1935 2 Sheets-Sheet l g ltomeys May 25, 1937. P. B. BOTTING. SR

CENTER PUNCH Filed. Nov. 23, 1935 2 Sheets-Sheet 2 Inventor Patented May 25, 1937 uN T osTA'rss PATENT OFFlE CENTER PUNCH Percy B. Betting, Sr., 'rmup, Tex.

Application 4 Claims.

My invention relates generally to means for positively guiding a hacksaw or the like in cutting rods and tubing, and particularly to a device of this character which includes means for marking and indicating the axial center of rods of different diameters either before or after cutting, and an important object of the invention is to provide an arrangement of this kind which is simple, rugged and eflicient and can be constructed in a well finished form at a relatively low cost. l

Another important object of the invention is to provide an arrangement of the character indicated which enables quickly and easily holding a rod, being one of several different sizes ofrods, and punch marking one end thereof at its axial center, the arrangement being easily and quickly adjustable for center punching the difierent sizes of rods.

Other important objects of my invention will be apparent from a reading of the following description in connection with the drawings, wherein for purposes of illustration I have shown a preferred embodiment of the invention.

In the drawings:-

Figure 1 is a general top plan view of the embodiment.

Figure 2 is a side elevational view taken'from the right of Figure 1 and showing the same applied to a rod.

Figure 3 is a transverse vertical sectional view taken through Figure 1 approximately on the line 3-3 and looking toward the left'in the direction of the arrows.

Figure 4 is a horizontal sectional view taken through Figure 1 approximately on the line 4-4 and looking downwardly in the direction of the arrows.

Figure 5 is a top plan view of the embodiment showing the center punch arm in an adjusted position and applied to one end of a rod.

Figure 6 is a horizontal sectional View taken through Figure 5 approximately on the line 6-6 and looking downwardly.

Figure '7 is a top or edge view of the center punch arm.

Referring in detail to the drawings, the numeral 5 generally designates the body of the device in an embodiment chosen' for illustrative purposes, and the said body is composed of two identical circular plates 6 and l which have disposed between the lower part thereof the segmental separator 8. The plates 6 and 1 are to be of properly tempered metal to resist cutting by the hacksaw, Whereas the separator 8 need be only November 23, 1935, Serial No. 51,338

of structurally adequate material. Double ended rivets 9 and Ill arranged in circumferentially spaced radial pairs traverse the lower parts of the plates 6 and I and the separator 8, the heads of the rivets being conveniently countersunk as shown.

Inverted heart-shaped registering openings l l and I2 are provided in the respective plates 6 and l, the three-quarter circular portion of these openings conveniently having the radius of curvature thereof at the approximate center of the said plates.

Both of the plates and the separator 8 are traversed by a screw bore I3 which is axially aligned with the junction M of the acutely angulated sides l5'and l6 of the upper portion of the respective openings in the plates 6 and L the said sides l5 and l6 being isosceles; and a rod or tube tightening screw ll is threaded in the said bore and has a reduced plain head l8 engageable with the rod or tube and an operating knurled knob IE3 at its opposite end and of sufficient size to enable strongly clamping the screw manually and without the use of tools. The manner of clamping a rod is illustrated in the drawings wherein the numeral 20 generally designates a rod.

The left hand side of the top plate 6 is provided at opposite sides of the opening H with pairs of punch arm lug receiving holes 2|, while the opposite side is provided with similarly arranged pairs of lug receiving openings 22. The left hand series of openings 2! are positioned with the first pair of holes on'the horizontal di'-.

ameter of the opening II, with each succeeding pair of holes spaced thereabove at increasingly less distant points, and the same arrangement obtains in the case of the lug receiving openings 22. The left hand lug receiving openings 2| are spaced at odd distances while the lug receiving openings 22 on the right side of the plate are spaced at even distances of some suitable linear measurement unit or units, such as centimeters or inches, the left hand openings being arranged to come between the adjacent pairs of openings 22 in the scale of measurement chosen in the manner indicated.

The various lug receiving openings 2| and 22 traverse the plate 6 to receive the pairs of lugs 23 on the punch arm which is generally designated 24 and which includes the elongated plate 25 intermediate the ends of which is the finger knob 26 and at the end opposite the lugs 23 the center punch 21. The lugs 23 are riveted as indicated by the numeral 28 in openings in the plate while the center punch 21 has its point and its head 29 riveted on opposite sides of the plate 25 as clearly shown in Figures 6 and 7.

A latch generally designated 30 is of relatively spring material and has a portion 3| pivoted as indicated at 32 to the upper face of the plate 6 and has a raised portion 33 which includes an operating knob 34 which is designed to frictionally engage Over the head 29 of the center punch while the punch arm is in the inoperative position illustrated in Figure 1. In this position of the punch arm the lugs 23 thereof are engaged in two of the holes 22 in adjacent outer end pairs thereof. Simply by operating the latch 3| so as to disengage the raised portion 33 thereof from the head 29 of the center punch on the arm 24, the arm 24 may be lifted away from the plate 6 so as to disengage the lugs 23 thereof from the openings 22. The punch arm 24 may then be selectively disposed in any of the pairs of holes 2| and 22, as indicated generally in Figure 5, so that in the transverse position thus assumed, chordal with respect to the plate 6, the punch equipped end of the arm 24 extends into the openings II and I2 in position to engage the axial center of the properly disposed end of a rod such as the rod 20, which corresponds in diameter to the indicia disposed opposite the holes in which the punch arm lugs 23 are disposed.

When using the device of the invention solely for square cutting rods or tubing, the openings I l and I2 may receive rods or tubes up to the diameter thereof and the screw I! applied so as to lock the device in position on the rod or tube, whereat the hacksaw or the like may be applied between the plates 8 and 1 and the operation of cutting with the hacksaw performed, the blade of the hacksaw being accurately guided for a predetermined cut of the rod or tube by reason of its engagement with the inner facing sides of the plates 6 and 1. The edges of the facing sides of the plates are beveled or rounded as indicated by the numerals 35 so as to facilitate entering the saw between the plates and to prevent binding the operation of the saw blade.

Although I have shown and described herein a preferred embodiment of my invention, it is to be definitely understood that I do not desire to limit the application of the invention thereto, and any change or changes may be made in the materials, and in the structure and arrangement of the parts, within the spirit of the invention and the scope of the subjoined claims.

What is claimed is 1. A device of the character described comprising a body, said body being formed with a rod receiving opening, a center punch arm adjustably mounted on said body, a punch point carried by the arm and arranged to be positioned at the axial center of the end of a rod disposed in said opening by adjustment of said center punch arm to a position on said body determined by the diameter of the rod, and a latch on said body engageable with said punch arm to hold said punch arm in an inoperative position.

2. A device of the character described comprising a body composed of a pair of spaced plates, said plates being formed with rod receiving openings having registering portions, a center punch arm adjustably mounted on one of said plates, a punch point carried by the arm and arranged to be positioned at the axial center of the end of a rod disposed in said openings by adjustment of said center punch arm to a position on said plate determined by the diameter of the rod, and a clamping screw traversing said body and entering said openings between the plates for engaging the rod so as to clamp the rod equally against the edge portions of said openmgs.

3. A device of the character described comprising a body, said body being formed with a rod receiving opening, a center punch arm adjustably mounted on said body, a punch point carried by the arm and arranged to be positioned at the axial center of the end of a rod disposed in said opening by adjustment of said center punch arm to a position on said body determined by the diameter of the rod said body having 7 spaced openings therein and said center punch arm including lug means selectively engageable with said spaced openings on said body.

4. A device of the character described comprising a body composed of a pair of spaced plates, said plates being formed with rod receiving openings having registering portions, a center punch arm adjustably mounted on one of said plates, a punch point carried by the arm and arranged to be positioned at the axial center of the end of a rod disposed in said openings by adjustment of said center punch arm to a position on said plate determined by the diameter of the rod, a separator disposed between and maintaining said plates in fixed separated positions and a clamping screw traversing said body and entering said openings between the plates for engaging the rod to clamp the same equally against the edge portions of said openings.

PERCY B. BOTTING, SR.

Images