US2847051A

US2847051A - Edger means for bending the edge of a can blank

Info

Publication number: US2847051A
Application number: US647144A
Authority: US
Inventors: Roland E Renard
Original assignee: National Can Corp
Current assignee: National Can Corp
Priority date: 1954-05-03
Filing date: 1957-03-19
Publication date: 1958-08-12
Anticipated expiration: 1975-08-12

Description

Aug. 12, 1958 R. E. RENARD 2,847,051 EDGER MEANS FOR BENDING THE EDGE OF A CAN BLANK Original Filed Ray 3 1954 2 Sheets-Sheet 1 INVENTOR. ROLAND E- REWARD l4 3 I J ByWLwQL ATTORNEY Aug. 12, 1958 R. s. RENAR D EDGER MEANS FOR BENDING THE EDGE OF A CAN BLANK Original Filed May 3, 1954 2 Sheets-Sheet 2 Whv INVENTOR.

1 ROLAND E.

REWARD ATTORNEY United States Patent EDGER MEANS FOR BENDING THE EDGE OF A CNN BLANK Roland E. Renard, Los Gatos, Calif., assignor to National Can Corporation, Chicago, 111., a corporation of Delaware 7 Claims. (Cl. 153-16) This invention relates to a new and improved can body maker and more particularly to the edger station thereof. Reference is made to my copending application Serial No. 427,244, filed May 3, 1954, for Can Machine and Method, of which the present application is a division.

A modern can bodymaker is a machine having a series of longitudinally spaced work and idle stations and feed mechanism to advance body blanks from station to station. Body blanks are fed into a laterally offset hopper at the front of the machine, withdrawn from the hopper one at a time, and advanced transversely to the center of the machine. Upon reaching the center of the machine, the blanks are then fed longitudinally from station to station. The principal stations of the machine comprise the following:

Cross feed station 1 at which the blanks are fed from the hopper transversely to the center of the machine.

Idle station 2 to provide room for the adjacent work stations.

Notching station 3 at which the corners of one longitudinal edge of the blank are notched to eliminate unnecessary overlapping when the blank is formed in a cylinder and the other longitudinal edge is slit adjacent the corners to facilitate subsequent bending of the edges.

Idle station 4 similar to station 2.

Edging station 5 at which the longitudinal edges of the blank are bent backwardly in hooks. In the instant machine the edging operation is performed at a single station, whereas in other bodymakers the edging is many times performed at two stations.

Idle station 6 is similar to stations 2 and 4.

Forming station 7 where the blank is formed into a cylinder, the hooked longitudinal edges being interlocked and the seam secured by hammering.

The advance of the can-body blank from station to station longitudinally of the machine is accomplished by a pair of feed bars which reciprocate longitudinally on opposite sides of the center. The feed bars carry opposed feed fingers, corresponding to the number of stations, which, on the feed stroke of the machine, engage the body blank and move it forwardly one station.

A further feature of the invention resides in the construction of the parts of the edger station. In many conventional bodymakers, edging of the blank is accomplished at two different stations. In such bodymakers the first edging operation involves a vertical movement of an edging steel which bends the marginal edge of the blank at approximately a right angle to the blank. At the second edging station of such prior constructed bodymakers, the edge of the blank is bent backward so that it assumes an acute angle with respect to the blank. The employment of a two-stage edger increases the number and complexity of the working parts and, more importantly, increases the necessary length and weight of the feed bars, a principal limitation on the maximum speed of the machine.

In some prior constructed bodymakers, edging is performed at a single station by means of a complex mechanical movement which moves an edging steel first vertically and then inwardly relative to the blank. Such single station edging mechanisms have required use of reciprocating parts and complex, slow-speed movements which have limited the maximum speed of operation of edging and the capacity of the machine. The present invention employs a single edging station, but employs at the single station two edging steels which operate in sequence, one bending the edge of the blank approximately at right angles and the other bending the edge back at an acute angle with respect to the blank. The two steels are driven by eccentrics at a higher rate of speed than if a cam shaft were employed.

Other objects of the present invention will become apparent upon reading the following specification and referring to the accompanying drawings in which similar characters of reference represent corresponding parts in each ofthe several views.

In the drawings:

Fig. l is a fragmentary top plan of a can bodymaker in which the present invention is employed;

Fig. 2 is a fragmentary side elevation of the structure of Fig. 1; and

Figs. 3, 4 and 5 are transverse vertical sectional views taken substantially along the lines 33, 44 and 5--5, respectively, of Fig. 2 and showing the mechanism in different positions of its cycle of operations.

The machine incorporating the present invention is exceedingly complex and consists of various sub-assemblies, many of which are conventional in the can-making art. Accordingly many of the parts of the machine have been eliminated or described only very briefly.

As will be understood by one skilled in the can-making art, in the can bodymaker metal blanks are fed into the machine one at a time and at one stage of operation of the machine notches and slits are cut on opposite side edges of the body blank at a notching station. Thereafter blank 20 is moved by feed fingers 72 to the edger station and the blank is clamped against feed table 39 on side table 23 by a longitudinally extending clamp bar 156 on each side of the machine.

On each side of the machine longitudinally extending side table 23 supports a longitudinal, horizontal side shaft 27. Side tables 23 have vertical side rails 28 which extend rearwardly behind the notching station to the forming station and are located inwardly and above shaft 27.

zontally reciprocating feed bar 56, driven by means not shown in timed relation to rotation of side shaft 27 The outer edges of feed bars 56 fit into longitudinally, horizontally extending ways 68 formed as grooves in the inner vertical faces of rails 28 of side tables 23 and are held therein by retaining plates 69 which are connected to the rails by screws 71.

Pressure bar spine 30 has a plurality of laterally projecting ears 81 which are connected to longitudinally extendiug skid supports 82. Below supports 82 are short, horizontal, longitudinal presser bar skids 83, each presser bar skid being a short longitudinal, horizontal foot having vertical pins 84 biased downward by springs 86 from supports 82 so as to create a drag restraining any tendency of the moving blank 20 to slide by inertia beyond its proper station.

The outer edge of the clamp bar is formed in a wedge with its upper edge 157 directed inwardly in an acute angle to co-act with the second operation edger steel to bend the edge of the blank at the same angle in a manner hereinafter set forth. Clamp bars 156 are actuated in a short arcuate travel by yoke 158 which is pivotally mounted on pivot shaft 159 journalled in bosses 161 on side table 23. A vertically movable adjustment screw 162 On either side of the machine is a longitudinally horithreaded into longitudinal connecting portion 163 of yoke 158 contacts the upper end of cam rod 164, the lower end of which is provided with a cam follower roller 166 which engages cam 167 on side shaft 27. Cam rod 164 has an enlarged guide 168 which is received within a bore in bracket 169 which is attached to side table 23. Spring 171 is interposed between guide 168 and a cap 172 threaded into bracket 169 to keep follower 166 in contact with cam 167. Timing of cam 167 is such that during the cycle when the blank is feeding from station to station, clamp bar 156 is raised in the position shown in Fig. 3 of the accompanying drawings. When the blank has come to rest, cam rod 164 is lifted, which causes yoke 158 to rock about pivot shaft 159 until the clamp assumes the position shown in Figs. 4 and 5, whereupon it clamps the blank between clamp bar 156 and feed table 39.

At the edger station are first operation and second operation edger steels 173 and 174, respectively, extending longitudinally. There is a set of steels on each side of the machine. The first operation steel 173 is held in a rocker arm 176 which is pivoted on pivot shaft 159 and the end of the rocker arm opposite first steel 173 is provided with a boss 177 through which fits wrist pin 178 which also passes through the bifurcated end 179 of a fitting 181 on the upper end of connecting rod 182. The lower end of connecting rod 182 is formed with an eccentric strap 183 and cap 184 which engage the eccentric 186 on side shaft 27. As side shaft 27 revolves, rocker arm 176 rocks around pivot shaft 159 causing a cycle of movement of the first operation steel, as hereinafter described.

Second operation steel 174 is likewise engaged by second rocker arm 187 which is pivotally mounted on pivot shaft 159, the opposite end of which is formed with a boss 188 through which fits wrist pin 189 which also passes through the bifurcated upper end 191 of second connecting rod 192, the lower end of which is provided with an eccentric strap 193 and cap 194 which pass around second eccentric 196 on side shaft 27. As side shaft 27 revolves, second steel 174 is rocked through a cycle of operations hereinafter described in detail.

First operation steel 173 comprises three parts, an uppermost curved flank 201 which has its center of curvature on the axis of pivot shaft 159, a transverse shoulder 202 and a lower flank 203. During the feed cycle of the machine, the first steel is approximately in the position shown in Fig. 3 whereby upper flank 201 is at the level of feed table 39 so that the outer edge of blank 20 contacts the flank and is thus centered relative to the machine. After clamp bar 156 has clamped the blank against the side table, as shown in Fig. 4, the cycle of the first steel brings shoulder 202 upward so that it engages the bottom surface of the edge of blank 20 and bends it upwardly against the outer edge of clamp bar 156. One feature of the present machine is that the axis of righthand pivot shaft 159, as shown in the accompanying Figs. 3, 4 and 5, is located above feed table 39. Hence pivotal movement of shoulder 202 produces a glancing, upward, inward movement rather than a straight vertical movement and the bending of the blank 20 is less likely to cause rupture than in ordinary edger mechanisms.

After first steel 173 has risen to the position shown in Fig. 4, it begins to retract until it reaches the position shown in Fig. at the bottom of its cycle and is out of the way to permit second operation steel 174 to come into operative position.

The lower edge 204 of second operation steel 174 has a slanted surface which is complementary to the surface 157 of clamp bar 156, the angle being the desired ultimate angle of the bent-back edge of blank 20 relative to the main body of the blank. Second operation steel I74 moves down to the position shown in Fig. 5 and bends the edge of blank 20 back against clamp bar 156 to the position shown.

After the sequence of operation shown in Fig. 5 has been completed, second operation steel 174 moves upward until it eventually reaches the position shown in Fig. 3 and clamp 156 moves upward to the position shown in Fig. 3. Upon release of blank 20 from between the clamp bar and feed table, the blank is free to move longitudinally of the machine.

Steels 173 and 174 shown in Figs. 3-5, inclusive, are on the righthand side of the machine as viewed from the front. On the righthand side, the edge of the blank is bent upwardly and inwardly. On the lefthand side of the machine, however, the edge of the blank is bent downwardly and inwardly. Accordingly, on the lefthand side of the machine (not shown) pivot shaft 159 is below the level of feed table 39; first and second operation steels 173 and 174 are inverted from the position shown in Figs. 3-5 and the edge of feed table 39 is formed wedge-shaped, resembling lower edge 157 of clamp bar 156. The construction of the lefthand side of the edger station will be apparent to one skilled in the can-making art from a consideration of the description and illustration of the righthand side of the machine which has been set forth.

Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it is understood that certain changes and modifications may be practiced within the spirit of the invention and scope of the appended claims.

What is claimed is:

1. Edger means for a can bodymaker for bending the edge of a can blank backwards at an acute angle comprising a first steel, a second steel, means for mounting said first and second steels, for pivotal movement, clamp means for holding a can blank with one edge engaging said first steel, means for separately pivoting said steels in sequence to first move said first steel in one direction against the edge of said blank to bend said edge approximately at about said clamp means, and then to move said second steel in the opposite direction to bend said edge backward at an acute angle about said clamp means.

2. Edger means according to claim 1 in which is provided a pivot shaft for said means for mounting said first and second steels, said pivot shaft being offset from the plane of said bank in the direction in which said edge is bent.

3. Edger means according to claim 1 in which said first steel has a locating flank curved about the center of pivotal movement of said first steel, said flank being adapted to restrict outward sideward movement of the blank prior to clamping of said clamp means.

4. Edger means according to claim 1 in which said first steel has a locating flank curved about the center of pivotal movement of said first steel, said flank being adapted to restrict outward sideward movement of the blank prior to clamping of said clamp means, and a shoulder behind said flank in respect to the direction of working movement of said first steel, said shoulder being adapted to engage the edge to be bent and bend said edge.

5. Edger means according to claim 1 in which said first steel has a locating flank curved about the center of pivotal movement of said first steel, said flank being adapted to restrict outward sideward movement of the blank prior to clamping of said clamp means, and a shoulder behind said flank in respect to the direction of working movement of said first steel, said shoulder being adapted to engage the edge to be bent and bend said edge, said edger means further comprising a pivot shaft for said means for mounting said first steel, the center line of said shaft being offset from the plane of said blank in the direction in which said edge is bent so that said shoulder moves against said edge in an inward, glancing stroke.

References Cited in the file of this patent UNITED STATES PATENTS Curtis Aug. 15, 1916 LaXo Dec. 13, 1955