US 3186244 A
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Description (OCR text may contain errors)
June 1, 1965 T. R. BAKER ETAL DRIVE MECHANISM FOR THE PLUNGER OF A PLUNGER-AND-DIE TYPE FOLDING BOX MACHINE 3 Sheets-Sheet 1 Filed Dec. 1. 1961 IIIIIlIIIIllIll/IIIA INVENTOR. Thomas R. Baker BY Cbesfer J. Pierce, Jr.
" A rroze/vzr June 1, 1965 T. R. BAKER ETAL DRIVE MECHANISM FOR THE PLUNGER OF A PLUNGER-AND-DIE TYPE FOLDING BOX MACHINE 3 Sheets-Sheet 2 Filed Dec. 1. 1961 Fig. 3
INVENTOR. Thomas R. Baker Chesfer J. Pierce, Jr.
Y H-Mak M ATTORNEY v J1me 1965 T. R. BAKER ETAL 3,186,244
DRIVE MECHANISM FOR THE PLUNGER OF A PLUNGER-AND-DIE TYPE FOLDING BOX MACHINE Filed Dec. 1. 1961 v 3 Sheets-Sheet 3 INVENTOR. Thomas R. Baker YC/veS/er J. Pierce,
ATTORNEY DRIVE MECHANISM T01 THE PLUNGER OF A PLUNGER-AND-DIE TYPE FOLDING BOX MACHINE Thomas R. Baker, 'Los Altos, and Chester J. Pierce, Jr.,
Palo Alto, Calif., assignors, by mesne assignments, to Bradford Speed Packaging and Development Corp., New York, N.Y., a corporation of Delaware Filed Dec. 1, 1961, Ser. No. 156,430 3 Claims. (Cl. 74--103) ing box shells and inserting liners into the shells.- In
order to fit a folding box with a liner properly, the liner must be inserted to the full depth of the folding box. This is conveniently accomplished by a plunger-like ejector device which may be a portion of the liner folding plunger. After folding of the liner the ejector plunger travels a greater distance than the remainder of the assembly in order to seat the liner tightly against the .bottom of the box body into which the remainder of the assembly does not enter. The length of the stroke of the inserting plunger device is critical, and difficulties are experienced it two or more blanks adhere accidentally to one another, are formed, and are inserted into a folding box shell. In such a case the clearance between the bottom of the inserting plunger and the bottom of the box shell, which is normally equal to the caliper of the single liner, is insufficient and the mechanism is damaged.
The invention provides an improved mechanism which, though positive in action, prevents such damage to the plunger device or its drive mechanism.
Occasionally, for the production of a particular box a plunger stroke is required which exceeds the length of the available stroke of the plunger drive bar to which the plunger is fastened. This makes it necessary to em ploy a larger machine, though all other dimensions and data of the smaller machine with the exception of the drive bar stroke are satisfactory.
The present invention provides a drive mechanism which permits the plunger stroke to be extended beyond the limits of the drive bar or the equivalent reciprocating element of the machine.
In still other instances it may be desirable to modify the motion characteristics of the plunger drive in such a way as to speed up or slow down the plunger during certain portions of the stroke.
This is attained by the invention by superimposing upon the motion of the drive bar or the equivalent element a cam-derived motion which extends or modifies the stroke or motion characteristics in the desired manner.
The cam device employed in this connection may be so constructed as to provide a yielding drive in one direction, but a non-yielding drive in the opposite direction. Also, the amount of foroeunder which the drive yields may be made variable. It may be greater near one end of the stroke than near the opposite end of the stroke. This is accomplished, for example, by a cam device in track form, one-half of which is yieldable and the other half of which is not.
These .and other objects, features and advantages of the invention will appear more fully in the detailed description which follows accompanied by drawings showing, for the purpose of illustration, a preferred embodiment of the invention. The invention also resides in cer- United States Patent O "Ice tain new and original features of construction and combination of elements hereinafter set forth and claimed.
Although the characteristic features of this invention which are believed to be novel will be particularly pointed out in the claims appended hereto, the invention itself, its objects and advantages, and the manner in which it may be carried out may be better understood by referring to the following description taken in connection with the accompanying drawings forming a part of it, in which:
FIG. 1 is a diagrammatic representation of a drive mechanism for reciprocating the plunger drive bar;
FIG. 2 is an elevational view, partly in section, and on an enlarged scale, of a blank forming assembly comprising a main plunger and a further plunger for inserting the formed blank into a separate box structure, the assembly being shown on the drive bar of FIG. 1;
FIGS. 3 and 4 are perspective views of portions of the mechanism for modifying the drive bar-produced plunger motion, the mechanism being shown in the two terminal phases of operation;
FIG. 5 is an elevational view, partly in section, of a blank forming plunger on the drive bar, the drive bar stroke being extended according to the present invention;
FIG. 6 is an elevational view, partly in section, of a plunger of the type shown in FIG. 2 attached to the stroke extending mechanism.
In the following description and in the claims various details will be identified by specific names for convenience. The names, however, are intended to be generic in their application. Corresponding reference characters refer to corresponding parts in the several figures of the drawings.
The drawings accompanying, and forming part of, this specification disclose certain specific details of construction for the purpose of explanation of broader aspects of the invention, but it is understood that structural details may be modified in various respects without departure from the principles of the invention and that the invention may be incorporated in other structural forms than shown.
FIG. 1 illustrates a typical drive mechanism for reciproeating the drive bar of a plunger-and-die type folding box forming machine.
A plunger drive bar 11 is carried by a cross head 12 slidable on a guide column 13 whose ends are supported in the machine frame at 14 and 15.
A drive shaft 16 carries a crank 17 from which a connecting rod 18 extends to an oscillating lever 19 pivotally mounted in the machine frame at 20.
As the crank 17 turns, the free end 21 of the lever oscillates and its motion is transmitted to the cross head 12 by a further connecting rod 22. The plunger drive bar 11 accordingly performs one up and down stroke foreach rotation of the crank 17. -A plunger mounted on the drive bar therefore enters its corresponding folding die and is retracted from it, forming one box for each revolution of the shaft 16.
The maximum stroke the plunger can perform is limited by the machine geometry, and it has therefore been necessary in the past to employ a larger machine than was otherwise required when a particularly long plunger stroke was needed.
FIG. 2 illustrates the basic construction of a box liner forming plunger equipped with means for inserting the formed liner into a separately formed box. The plunger body 23 is supported by a stem 24 having a mounting flange 25 and clamping plate 26 for securing the assembly to the drive bar 11.
'A separate bottom plate or inserting plunger 27 on a separate stem 28 is normally retracted by a spring 29 hearing against a washer 30 and a pin 31 fixed in the stem 28. The pin 28 may pass through an elongated hole in the outer stem 24 in the case of a concentric stem artrangement. An actuating lever 35 provided with a roller 32 and mounted on a pivot arm 33 causes the bottom plate 27 to be projected when the lever 35 is deflected in the direction of the arrow 34, for example by striking a horizontal plate on the folding die through which the plunger passes, as described more particularly in the aforesaid Patent 2,837,013.
FIGS. 3 and 4 illustrate a representative drive assembly embodying the invention.
The cross head 12 which carries the drive bar 11 is best seen in FIG. 3, the guide column 13 on which the cross head 12 moves is best seen in FIG. 4.
A tilt shaft 36 is mounted on the drive bar in bearings 37 and 38 and carries a plunger actuating arm 39 for attachment to the plunger to be moved through an extended or modified stroke. The arm 39 is clamped to the tilt shaft 36, hence tilts with it.
A further arm 49 clamped to the end of the tilt shaft 36 is constructed as a cam follower and carries a roller (not visible) on a stud 41 movable in an elongated cam track 42 mounted alongside the path of the drive bar and in general at a slant to the path of the drive bar and tilt shaft.
The cam device 42 may be constructed in two parts, one of which is movable relatively to the other. As shown in the figures, cam portion 43 is fixedly mounted on the machine frame at 44 while cam portion 45 is pivotally mounted at 46 and is urged by a spring 47 towards the portion 43.
In the illustrated arrangement the force required for separating the two cam portions is greater within the top portion of the stroke than within the bottom portion. Reversal of pivot 46 and spring 47 would produce the opposite characteristic which, therefore, can be varied to suit the specific arrangement.
A switch is visible at 48 which may be used to stop the machine in the case of separation of the two cam portions, or to signal that condition.
The cam track may be shaped to produce any desired motion characteristic for the plunger actuating arm 39.
In order to illustrate the extent of tilt of the lever mechanism 36, 39, 40, two pieces of tape were applied as markers to shaft 36 and bearing 37 at 49. In FIGS. 3 these markers are in coincidence at the top of the stroke. During the downward stroke of the drive bar 11 the tilt arm 40 on the tilt shaft 36 moves in a clockwise direction as the roller stud 41 follows the cam track, thus oscillating the shaft 36 and the plunger actuating arm clockwisely. FIG. 4 shows one marker advanced with respect to the other at the bottom of the stroke. This indicates the extent of the clockwise oscillation of the shaft. A corresponding counterclockwise oscillation occurs during the upward return stroke of the drive bar 11.
The plunger assembly of FIG. 2 is combined with the drive mechanism by attaching the flange 25 of the main plunger stem 24 to the mounting clamp and flange 50 causing the plunger 23 to move with the drive bar 11. The stem 28 is attached to the arm 39 which imparts an enlarged stroke to the stem 28 causing the bottom plate 27 to separate from the remainder of the plunger 23 at the bottom end of the stroke. This is shown in broken lines in FIG. 6.
An example of a single extended stroke plunger is shown in FIG. 5. The stem 124 of the plunger 123 extends through a bushing 150 fastened on the drive bar 11 and the plunger stem is moved by the arm 13-9 on the tilt shaft.
In the mechanism shown in FIGS. 3 and 4 the cam track 45 controlling the down stroke is made yielding. This arrangement compensates for extra board thickness in the event of accidental feeding of more than one blank at a time. No damage results in that case and the machine may be stopped by actuation of the switch 48.
Obviously both cam portions may be yieldingly arranged. The cam track may be shaped to produce any desired motion characteristic of the plunger. Such modifications will be apparent. to ,persons skilled in the art on the basis of the foregoing description and drawings.
What is claimed is:
1. Drive mechanism for the plunger device of a plungerand-die-type folding box machine, the mechanism comprising, in combination, a drive element mounted on the machine frame for substantially straight line motion; power means for imparting a reciprocating motion to said element; a lever means tiltably mounted on said drive element, said lever means comprising two arms, one arm being shaped to attach to the plunger device, the other arm being shaped as a cam follower; means forming a longitudinally extended cam track mounted on the machine frame alongside the path of said drive element, said cam track being split lengthwise into two portions, one portion being fixedly mounted, the other portion being movable with respect to the fixed portion; means for resiliently urging said movable cam portion towards said fixed portion, said cam follower being engaged between said track portions said cam track means being so disposed with respect to the path of the drive element as to oscillate the lever means about its axis as the drive element moves back and forth.
2;. Drive mechanism for the plunger device of a plungerand-die-type folding box machine, the mechanism comprising, in combination, a drive bar mounted on the machine frame for substantially straight line translatory motion parallel to itself; ower means for imparting a reciprocating motion to said drive bar; a tilt shaft mounted on said drive bar for oscillation about the tilt shaft axis; a first plunger actuating lever mounted on said tilt shaft; a longitudinally extended cam mounted on the machine frame alongside the path of said drive bar, said cam being divided lengthwise into a portion fixed with respect to the machine frame and a movable portion adapted to move towards, and away from, said fixed portion; biasing means for urging said movable portion towards said fixed portion; a second lever mounted on said tilt shaft; a cam follower on said second lever, said follower moving in the cam track between said fixed and movable portions, the cam being so disposed relatively to the path of the drive bar as to tilt said second lever and oscillate said tilt shaft about its axis as the said drive bar moves back and forth; and means responsive to displacement of said movable cam portion for rendering said power means inoperative upon displacement of said movable portion against the action of said biasing means.
3. Drive mechanism for the plunger device of a plungerand-die-type folding box machine, the mechanism comprising, in combination, a drive bar mounted on the machine frame for substantially straight line translatory motion parallel to itself; power means for imparting a reciprocating motion to said drive bar; a tilt shaft mounted on said drive bar for freedom to oscillate about the tilt shaft axis; a first plunger actuating lever mounted on said tilt shaft; a longitudinally extended cam on the machine frame alongside the path of said drive bar, said cam being divided lengthwise into a portion fixed with respect to the machine frame and a movable portion adapted to move towards, and away from, said fixed portion; means for urging said movable portion towards said fixed portion; a second lever mounted on said tilt shaft; and a cam follower on said second lever, said follower moving in the cam track between said fixed and movable portions, the cam being so disposed relatively to the path of the drive bar as to tilt said second lever and oscillate said tilt shaft about its axis as the said drive bar moves back and forth.
(References on following page) References Cited by the Examiner UNITED STATES PATENTS Ball 74-99 X Ulrich et a1. 74--104 X Jones et a1.
Harris 74-40 McGauchie 74-110 Shoup 74-40 6 2,285,240 6/42 Tuchscherer 74-102 X 2,825,781 3/58 Mitchell 74-104 X 2,924,101 2/ 60 Sherman 741 10 X FOREIGN PATENTS 510,037 2/55 Canada. 1,041,585 10/53 France.
BROUGHTON G. DURHAM, Primary Examiner.