US 3018720 A
Description (OCR text may contain errors)
Jan. 30, 1962 P. F. NICHOLS 3,018,720
DEVICE FOR STAMPING CODE NUMBERS Filed June 12, 1959 2 Sheets-Sheet l Jaye/ f aw P5727? f. /V/ cl/OLS 3 I ifl y Jan. 30, 1962 P. F. NICHOLS DEVICE FOR STAMPING CODE NUMBERS 2 Sheets-Sheet 2 Filed June 12, 1959 Arluufl II THU h wlrlll uuuuw WH HN ZFrdezzZor 1 57-531? Mex/0L5 United rates Patent 3,018,720 DEVICE FOR STAMPING CODE NUMBERS Peter F. Nichols, Montreal, Quebec, Canada, assignor to Bowers Machine Company Limited, Montreal, Quebec, Canada Filed June 12, 1959, Ser. No. 820,043 4 Claims. (Cl. 101-41) The present invention relates to stamping devices and more particularly to devices of this nature adapted for stamping a code indicia on each of a series of articles as they are continuously fed along a moving conveyor belt.
As is well known, there is a problem in effectively and clearly stamping a number or symbol on a surface that is moving during the stamping operation, particularly when the stamping is performed as part of a production line assembly and by automatic stamping equipment. Since, in most cases the stamping equipment is stationary the movement of the articles as the stamp is being applied results in a smearing or elongation of the required symbol. Attempts have been made to overcome this problem by providing stamping equipment which rotates or moves with the conveyed articles, the idea being that the stamp and article travel in unison while the stamp is applied. These arrangements are somewhat cumbersome and complicated and do not lend themselves readily to high speed conveying arrangements. Other arrangements have been proposed to accelerate the stamping action to a point where the actual stamping contact is so brief that the smearing is reduced to a minimum but these again in general require complicated and costly equipment which presents problems in their installation in existing production line conveyor systems.
The present invention recognizes these problems and aims to provide a satisfactory solution by furnishing a simple compact stamping device which can be readily installed on any production line conveyor set-up and which can also be readily adjusted to stamp articles of varying sizes.
More specifically, the present apparatus performs a stamping operation through the action of an electrically or air-operated plunger depressing a spindle on the lower end of which is mounted a stamping device. A feature of this apparatus is that it is constructed and adjusted so that the stroke of the plunger is always shorter than the distance between the surface of the article to be stamped and the stamping device so that when the plunger reaches the end of its stroke the spindle continues by its own weight and momentum. This causes the stamping device to come in momentary contact with the article and then rebound to its original position.
In addition the stamping or printing device proper is constructed so that a slight rolling effect is achieved upon contact with the article so that the actual printing takes" place progressively in a direction opposite to the direction of travel so as to further minimize the possibility of blurring. This is accomplished by having the printing head mounted for restricted pivotalmovement and resiliently biasing it so that a front edge of the printing face is. first aligned with and in the printing motion first engages the surface of the article. This front edge of the printing face is provided with a driving or engagement bar of rubber or the like so that upon contact with the moving article the frictional engagement causes the printing head to pivot bringing the remainder of the printing face progressively into contact with the article. The resilient bias is arranged so that immediately the printing face starts to pivot it acts to accelerate the printing movement and on the up stroke acts to cock or return the printing face to the engaging position. In one preferred construction, a solenoid having a sliding armature and a stamp supporting spindle are aligned one above the other but are not connected and the spindle is spring biased towards the solenoid so that the stamping action is very rapid. A similar effect is achieved with an air cylinder and piston in place of the solenoid. The solenoid or air cylinder is triggered by suitable means, for example av Having thus generally described the nature of the invention, particular reference will be made to the accompanying drawings showing by way of illustration a preferred embodiment thereof, and in which:
FIGURE 1 is a perspective plan view showing by way of illustration and somewhat diagrammatically a portion of a can-conveying arrangement having a stamping arrangement according to the invention mounted in the path of the conveyor.
FIGURE 2 is a front view of the arrangement shown in FIGURE 1 with the casing broken away to show the internal mechanism more clearly with the can guide rails also shown in section to illustrate the relative position or. the can and the controlling micro-switch.
FIGURE 3 is a side view of the construction shown in- FIGURE 2 with the casing in section to show the mechanism more clearly.
FIGURE 4 is a view of the upper portion of the arrangement shown in FIGURE 2 with segments in section to illustrate in more detail the construction and relative positions of the working elements of the stamping mecha nism as they would appear in normal at rest position.
FIGURE 5 is a cross-sectional side view of the construction shown in FIGURE 4 with the working elements shown as they would appear at the end of the solenoid plunger stroke with the marking stamp in initial contact with the top of a can.
FIGURE 6 is a fragmentary view corresponding to FIGURE 5 to show in full lines the beginning of the up movement of the stamping head bringing it into contact with the stop, and in broken lines the position of the printing head in inking position after it has passed the stop.
FIGURE 7 is a sectional view of the printing head to illustrate the mounting and resilient bearing of the pivotally mounted stamp bearing portion.
FIGURE 8 is a bottom plan view of the stamp portion showing the resilient friction or delivery bar.
FIGURE 9 is an enlarged detail view partially in sectionrof a portion of the construction as shown in FIGURE 2 to illustrate the resilient biasing of the pivotal stamp supporting portion in more detail.
FIGURE 10 is a diagram of a suitable electric circuit for the form of apparatus utilizing an electrical solenoid as the main actuating member.
FIGURE 11 is a sectional view of the upper portion of the stamping mechanism showing the alternate use of an air cylinder and piston as the main actuating member.
FIGURE 12 is a detail view of the lower end portion of an actuating plunger showing a spindle return dampening arrangement which may be utilized in combination with either actuating member.
With particular reference to FIGURES l, 2 and 3 of the drawings, a stamping arrangement in accordance with the invention is shown as being incorporated in a conveying system carrying a plurality of cans, for example cans operational point.
For the purpose of illustration the stamping mechanism is shown as being completely enclosed in a casing or housing and being mounted on suitable standards 12 above the run of the conveyor belt 14. The arrangement shown supports a stamping head provided with removable rubber type for the stamping of the required code indicia on the cans which will be described in more detail later.
As previously mentioned, the essential elements of the construction of the invention comprise of a printing head 20 mounted on a spring loaded sliding spindle 22 driven by a suitable plunger or piston, in the construction shown a solenoid 24 having a sliding core 26, and actuated by the triggering of a micro-switch 28, mounted in a suitable position in the path of the conveyor 14. A feature of this arrangement is that the stroke of the solenoid core 26 is not sufficient to bring the plunger or spindle 22 and the printing head 20 mounted thereon all the way down to meet the article, in the present case the top of one of the cans A." Accordingly, when the core 26reaches the end of its stroke the spindle 22 continues by its own momentum. This causes the stamping head 20 to momentarily contact the top of the can A and then by the action of the spring 23 rebound to its original position.
During this stamping action the printing head 20 performs a slight pivotal movement to bring the type face into progressive contact with the face of the can as will be described in more detail later.
Withparticular reference to FIGURES 4 and 5, the main elements are constructed and assembled in the following manner so as to provide means whereby the location of the mechanism and stroke can be readily adjusted to suit any variation in conveyor or article size.
As previously mentioned, the housing 10 is mounted on a horizontal standard member 12 by attachment of the back plate 11 with a nut and bolt assembly 15. The back plate 11 of the casing 10 is provided with side flanges 13 which retain the cover portion 10a in position when assembled. The solenoid 24 and a bearing block are mounted in line on the plate 14 so as to support the solenoid core 26 and the sliding spindle 22 in axial alignment. The bearing block 30 includes an axial recess 32 to accommodate a sleeve bearing 34 guiding the spindle 22 and also the spring 23 mounted over the upper end of the spindle. The upper end 21 of the spindle 22 is threaded and a pair of stop nuts 35 mounted on the spindle end provide a means of adjusting the spacing between the stamping surface 19 of the stamping device 20 mounted on the lower end of the spindle and the surface of the can to be stamped. Preferably, the spindle is adjusted so that there is about 4:" space between the top of the can and the stamp when the solenoid core 26 is fully extended against the spindle 22 so that the spindle travels this remaining /s" by its own momentum. This preferred setting of course may necessarily have to be increased if the rims of the cans are equal to V8" or more so as to ensure clearance of the stamp on the rebound or up stroke.
At the same time, the printing head 20 performs a slight pivotal movement bringing the type face into progressive printing contact with the can head during the momentary contact to further reduce the possibility of smearing or blurring of the printed impression if the cans are being conveyed at relatively high speeds. For this purpose the printing head 20 is made as having a type supporting base 33 having a corrugated surface adapted to receive interchangeable type and which is mounted between spaced supporting plates 39. The other ends of the plates 39 are pivotally mounted, as indicated at 25, to a supporting frame 43 secured to the lower end of the spindle 22. A shaft 31 extends between the plates 39 at a position offset from the pivotal connections 25 and compression rods 45 extend from the shaft 31 at each side to a loose connection with the frame 43. Springs 37 are mounted over each of the rods 45 between the frame 43 and shaft 31 and act as kick compression members to accelerate the pivotal movement of the printing head 20. This pivotal movement is caused initially, during the stamping movement of the spindle 22, by the frictional contact of a leading edge of the type face mounted on the base 33. To make this frictional contact more positive the leading edge of the type face is provided with a contact or delivery bar 47, preferably of rubber or the like, see FIGURE 8. As each contacted can proceeds, the engagement of the bar 47 causes the printing head 30 to pivot about the axes 25 bringing the selected type face progressively into printing contact with the surface of the can.
Almost immediately this pivotal movement has displaced the compression rods 45 past the centre of the pivotal axes 25 so that the springs 37, which were compressed, now aot to accelerate the pivotal movement, see FIGURE 9. In order that the printing head be returned to' ready position for each stamping with the springs 37 compressed, each plate 39 is provided with an outstanding cam portion 41 which is adapted to engage a stop 49 on the upward movement of the spindle 22.
In the construction shown, means in the form of swinging inking arms are provided to supply the printing surface of the stamp with ink between each printing stroke. In the construction shown, the bearing block 30 includes a' forward extension 36 to which there is pivotally mounted at each side inking arms 38. Each of the inking arms 38 is provided on its inner surface with throwoff rails 40 which are engaged by corresponding throwotf rollers 42 mounted on each side of the upper portion of the stamping head 20. Inking pads 50 are mounted between the inking arms 38 with the arms being normally biased against the printing surface of the stamping device 20 by a coil spring 53. With this arrangement, when the spindle 22 descends the throw-01f rollers 42 engage the rails 40 pushing the inking unit clear. When the spindle 22 retracts under the influence of the spring 53 the inking pad 50' again swings up into contact with the printing type.
In order that the cans A be guided into positive contact with the actuating switch 28 a pair of guide rails 60 are provided which are mounted one at each side of the conveyor run. These rails 60 are supported on adjustable sliding rods 62 so that the spacing between the opposed rails may be varied to suit any desired size of can A. The rods are supported in blocks 64 suitably bored to slidably accommodate the rods 62 and provided with thumbscrews 66 so that the rods can be locked in the desired position. The blocks 64 shown are each provided with a threaded pin 66 so that they can be assembled to the conveyor by drilling and tapping suitable holes in the conveyor frame. The ends of the guide rails 60 can be bent to any desired radius to suit the size of cans. With this arrangement, assuming the guide rails 60 are set to suit the diameter of the cans A, as the center of each can passes the switch 28 it actuates the solenoid 24 causing the stamping action described.
A suitable circuit is shown diagrammatically in FIG- URE 10 and it will be noted that this includes a timer 70 which provides an impulse to the solenoid having a duration only of about /6 of a second. This is to prevent double image which could possibly occur if the solenoid were energized during the full period of travel of a can beneath the apparatus which at times might be as long as 2 or 3 seconds. If the solenoid remains energized the stamping head spindle 22 on completing its free travel, rebounds due to the spring 23 and hits the energized solenoid core 26. This sometimes lifts the core slightly off its seat but the solenoid instantly urges it down again reactuating the spindle 22.
As indicated generally in FIGURE 11, a preferred alternative construction utilizes an air cylinder having a'spring biased piston 82 in the place of the solenoid 24 and plunger core 26. This arrangement includes a solenoid operated valve 86 to control the air under pressure to the cylinder 80. The circuit shown in FIGURE is also suitable for this arrangement, the solenoid indicated being the controlling valve solenoid 86. The remainder of the construction is the same as previously described and illustrated.
If desired, the timer 70 can be dispensed with and the problem of possible double image overcome by a mechanical arrangement as shown in FIGURE 12. This consists of having the lower end of the solenoid core 26 or the piston stem 82 threaded and mounting a hollow cup 94 thereon. A shock dampening disk 96, preferably of sponge-like cellular plastic or the like, is inserted in the cup 94 so as to dampen or prevent a rebounding of the stamp-ing head spindle 22. The only change necessary in the circuit shown is the elimination of the timer 70.
As shown most clearly in FIGURES 4 and 11, the easing back plate 11 supporting the solenoid 24 or the air cylinder 80 is provided with spaced apart supporting angles 13a, 13b having elongated attachment slots 90 to which the solenoid 84 or the air cylinder 80 is attached with nuts and bolts 92 so as to permit adjustment of the actuating members relative to the spindle 22. The bearing block 30 is fixedly attached between the angles 13a, 1311 by screws 31. Accordingly, the stroke of the spindle 22 relative to the cans A can be adjusted through the stop nuts 35' and the position of the solenoid core 26 or piston 82 relative to the spindle 22 adjusted to suit.
1. An automatic stamping apparatus adapted to apply a stamp code indicia in sequence to each of a plurality of articles continuously fed past said apparatus along a conveying path, said apparatus comprising a supporting standard member mounted across the convey-ing path, a plunger supporting and actuating member mounted on said standard above and in alignment with said conveying path, a plunger slidably mounted in said actuating member for driven reciprocal movement towards said conveying path,
means controlled by contact of each of said articles adapted to intermittently actuate said plunger actuating member, a bearing block mounted on said standard and a spindle slidably mounted in said bearing block in spaced axial alignment from and in axial alignment with said plunger with one terminal end of said spindle separate from and directly opposed to one terminal end of said plunger, a spring connected to and resiliently biasing said spindle terminal end towards said plunger terminal end, an indicia bearing stamp mounted for restricted pivotal movement on the terminal end of said spindle remote from said plunger, and resiliently biased compression members to align a forward edge of said stamp indicia bearing surface with the moving surface of an article to be stamped, said indicia bearing stamp forward edge supporting a resilient contact bar whereby on the downward stroke of said spindle the frictional engagement of said contact bar on said article is adapted through the movement of said article against said frictional engagement to pivot said indicia bearing stamp about said spindle connection progressively applying said indicia bearing surface to said article in a direction opposed to the movement of said article, and stop means on said standard adapted to engage and return said indicia bearing stamp to ready position on the upward stroke of said spindle.
2. An automatic stamping apparatus adapted to apply a code indicia in sequence to each of a plurality of articles continuously fed past said apparatus along a conveying path, said apparatus comprising a supporting standard mounted across the said conveying path, a plunger supporting and actuating member mounted on said standard above and in alignment with said conveying path, a plunger slidably mounted in said actuating member for driven reciprocal movement towards said conveying path, a bearing block mounted on said standard and a spindle slidably mounted in said bearing block in spaced relationship from and in axial alignment with said plunger with one terminal end of said spindle separate from and directly opposed to one terminal end of said plunger, a spring connected to and resiliently biasing said spindle terminal end towards said plunger terminal end, an indica bearing stamp pivotally mounted on the terminal end of said spindle remote from said plunger, resiliently biased compression members acting on said stamp to accelerate the pivotal movements thereof, and a resilient contact bar mounted on a forward edge of said indicia bearing stamp in a position to first contact said article by frictional engagement during the stamping movement of said spindle towards said article and urging said indicia bearing stamp into resiliently biased pivotal movement to progressively apply indicia supported by said stamp against an article contacted thereby in a direction opposed to the movement of said article, control means responsive to the contact of articles fed along said conveying path connected to and adapted to actuate said plunger actuating means and including a contact switch disposed in the path of said conveyed articles, the stroke of said plunger when actuated and said spindle being adjusted relative to each other and the distance to the surfaces of the articles to be stamped being such that the final stamping contact of said stamp with each of said articles is created solely by the continued travel of said spindle against said spring after the termination of said plunger stroke.
3. An automatic stamping apparatus as claimed in claim 2, wherein said plunger actuating means comprises an electrical solenoid and said plunger comprises a solenoid core, said contact switch being connected to said solenoid core.
4. An automatic stamping apparatus as claimed in claim 2, wherein said plunger actuating means comprises a fluid pressure cylinder and said plunger comprises a spring biased piston, said control means including a solenoid valve connected to said fluid pressure cylinder and to said contact switch.
References Cited in the file of this patent UNITED STATES PATENTS 2,443,779 Sanders et al. June 22, 1948 2,559,455 Meyer July 3, 1951 2,578,830 Park et a1 Dec. 18, 1951 2,787,950 Dorsch Apr. 9, 1957