Art of trimming cans or the like

Nov. 13, 1951 μ. halowich 2,575,104

ART OF TRIMMING CANS OR THE LIKE

Filed Nov. 4, 1946

<img file="US2575104A_D0001.tif" />

Patented Nov. 13, 1951

2,575,104

UNITED STATES PATENT OFFICE

2,575,104

ART OF TRIMMING CANS OB THE LIKE

Michael Halowich, Wausau, Wis., assignor to Gerhard-Haiowich Corporation, Wausau, Wis., a corporation of Wisconsin

Application November 4,1946, Serial No. 707,705

Claims.

The -present invention relates generally to improvements in the art of trimming the brims of cup-like articles and relates more specifically to an improved method of and apparatus for dressing the raw end edges of cans or similar articles formed of relatively rigid material.

The primary object of my invention is to provide an improved method of and apparatus for rapidly and -effectively trimming the brims of rigid cup-shaped articles formed of sheet metal or other relatively thin sheet-like material.

When nans or other cup-shaped articles .are extruded or drawn from -sheet material so as to provide seamless structures, the brims are ordinarily rough, and jagged, and must be dressed so as. to. provide smooth marginal edges. Heretofore it has been common commercial practice to trim these raw brim edges, of circular and noncircular cans, by revolving the successive eppshaped articles about their central axes and by presenting the revolving brims to cutters, but this method has proven quite unsatisfactory, mainly because the side wall distortion caused by rapidly rotating the flexible sheet metal receptacles prevented accurate trimming and frequently tore or left burrs and other waste material upon the can edges. While it has also been proposed to insert successive extruded or drawn sheet metal seamless cans or the like between dies which snugly engaged the internal and external surfaces of the cups, and by subsequently shearing the raw edges off with the aid of a revolving cutter; no proper provision was made with this prior proposal, for rapidly inserting and ejecting the successive cans into and out of the retaining dies without undesirable distortion and alteration in length, so that this method was too cumbersome and tedious for high speed operation and commercial use.

It is therefore a more specific object of this invention to provide an improved method of trimming circular or non-circular metallic or plastic cans or cups, whereby the articles may be properly dressed -to accurate dimensions in rapid succession and with minimum waste of material due to tearing of the thin receptacle stock.

Another specific object of the present invention is to provide simple and highly efficient apparatus for carrying on the commercial exploitation of my improved can trimming method.

(Cl. 82—2.5)

A further specific object of my invention is to provide means for facilitating high speed but efficient trimming of cans or other cup-shaped articles of diverse sizes and shapes, automatically 5 and with minimum danger of injury to attendants, and without side wall distortion.

.Still another specific object of the present in? vention is to provide improved instrumentalities for quickly presenting-successive cup-shaped ar? 10 tides to a -constantly revolving cutter for edge trimming purposes, and for immediately there? after ejecting the finished articles away from the zone of cutting without damage.

An additional specific object of the invention 15 is to provide an automatic can edge trimmer which is simple and compact in construction, and which is moreover highly efficient in operation and flexiblein.itsadaptations.

These and other specific objects and advan2o tages of the invention will be apparent from the following detailed description.

A clear conception of the several steps and fea? tures. involved in w improvement, and. of the operation of a typical machine adapted to ex23 ploit the improved: method, may be had by referring to the drawing accompanying and form? ing a pari, of this specification wherein like ref? erence characters designate the same or similar parts in the various views.

. Fig, 1 is a somewhat diagrammatic part sectional side elevation of a typical can trimmer embodying my invention, the section being taken along the vertical longitudinal central plane of tije unit while in the act' of trimming a can;

Fig; .2. is a fragment of a similar view of the can trimmer, but showing a trimmed can being ejected or delivered away from the cutting zone; and

Fig., .3 is a transverse vertical section through 40 the assemblage of Fig. 1, taken plppg the iipe 3—3 and viewed ip the direction of the arrows,

While the invention has been shown and described herein as having been embodied in a typical can trimmer operating upon metallic or plas45 tic cup-shaped receptacles having approximately, rectangular transverse cross-section, if is not my desire or intention tp unnecessarily limit the scope :or to restrict the utility of the improved features by virtue of this special embodiment.

Referring to the drawing, the typical machine

2,575,104 for carrying on the improved can trimming method and which is shown by way of illustration, comprises in general a base 6 providing a sturdy support for a fixed member 7 having one end of a horizontal stud 8 fixedly mounted therein, and being provided with a central opening 9 extending through both the member and the stud; a pulley or sheave 10 rotatably mounted upon the member 7 and stud 8 by means of antifriction bearings 11, 12 and being revolvable at high speed by a V-belt 13 coacting with a peripheral groove 14 formed in the sheave; one or more knife blades or cutters 16 firmly secured to an end face of the sheave 10 by means of cap screws 17, and haying sharp cutting edges revolvable about the stud 8 on the side of the pulley remote from the support member 7; a stationary plug or core 18 firmly but detachably secured to the opposite or overhanging end of the stud 8 with the aid of clamping screws 19, and being formed to slidably receive and to snugly fit the interiors of seamless drawn cans 20 or similar cup-shaped articles; an annular chuck 22 fixedly mounted upon the base 6 so as to surround the core 18 and being provided with radially movable clamping jaws 23 resiliently urged toward the plug by flexible means 24 such as springs or rubber blocks, and being guided in their movement by bolts 25 coacting with guide slots 26 or otherwise; a can chute 28 for conducting the successive untrimmed cans 20 into positions of alinement with the core plug 10 upon a stationary supporting block 29 secured to the base 6 on the side of the chuck 22 remote from the pulley 13 and member 7; an injecting plunger 30 movable horizontally across the top of the block 2S to snugly position the successive cans 20 upon the plug 18 between the chuck jaws 23; a knock-out rod 32 for the finished cans 20, reciprocable within the central opening 9 of the member 7 and stud 8 and being provided with a central passage or hole 33 communicable with a source of fluid under pressure such as compressed air; and a finished can ejecting plunger 34 movable horizontally across the top of the block 29 transversely of the direction of travel of the injector plunger 30.

The base 6 of the unit may be formed of any durable material and the member 7, chuck 22, and block 29 may be firmly secured thereto in any suitable manner as by welding, and the stud 8 should be rigidly secured to the member 7 in perfect axial alinement with the sheave 10 so that the anti-friction or ball bearings 11,12 will be truly coaxial with each other at all times. The knives or cutters 16 one or more of which may be utilized, should be firmly attached to the driving pulley 10 so as to prevent possible shifting of the cutters relative to their supporting sheave, and this sheave 10 may be driven by the belt 13 from any suitable source of power such as an electric motor, so as to revolve the knives at high speed. The bearings ί ί, 12 should also be so formed as to prevent possible displacement of the cutters 16 along the axis of the machine; and the end of the core plug 18 nearest the pulley 10, should be positioned and firmly held by the clamping screws 19 so that the cutting edges of the knives will just clear this plug end.

As previously indicated, the plug or core 18 should be formed to snugly but slidably fit the interiors of the particular cans 20 which are to be trimmed, and the chuck jaws 23 should also be formed to snugly but resiliently engage the ad4 jacent external can surfaces. As shown, the plug 18 and jaws 23 are adapted to coact with approximately rectangular cans of a definite length, but when circular or otherwise shaped longer or shorter cans or cups are to be trimmed, the internal core and external jaws may be quickly and conveniently replaced by other corresponding parts adapted to properly cooperate with the new sizes or shapes of the articles, by merely releasing the jaws retaining bolts 25 and removing the jaws 23, and by thereafter releasing the core clamping screws 19 and removing the plug, or by unscrewing the stud 8 from the member 7 and subsequently removing the plug (8 from the stud. The resilient means 24, which may be either springs or rubber blocks, urge the jaws 23 radially toward the central axis of the unit, and should be sufficiently strong and flexible to effect proper clamping of the cans 20 while being trimmed, but should not unduly resist admission and removal of the successive cans 20; and the entering ends of the jaws 23 should preferably be rounded as shown so as to properly guide the can edges toward the cutting zone.

The can supply chute 28 may be of any desired and well known type capable of delivering the successive untrimmed cans 20 upon the block 29, either by gravity or otherwise; and the horizontally movable can injecting plunger 30 may be positively reciprocated in any suitable manner and properly timed, so that it will positively move the successive untrimmed cups or cans 20 off of the block 29 into the chuck 22 and over the plug 13 into the path of the knives, and will be withdrawn so as to permit free ejection of the finished cans 20 from the cutting zone. Such removal of the trimmed cans 20 after each cutting operation has been completed, may be effected either mechanically alone with the aid of the knock-out rod 32, or by fluid pressure alone admitted through the passage or hole 33 in the rod 32 while the latter is held stationary, or by the combined action of the knock-out rod being moved and by the admission of fluid under pressure through the hole 33.

The knock-out rod 32 which snugly but slidably coacts with the longitudinal central opening 9 formed in the member 7 and stud 8, may be periodically reciprocated in any suitable manner by a cam or crank cooperating with its end nearest the member 7, and the central fluid conducting hole 33 extends from the can engaging end of the rod 32 to a point sufficiently remote from this end to insure proper delivery of ejecting fluid when both mechanical and fluid pressure knockout is being effected. The central passage 33 is constantly communicable through a series of lateral ports 36 with a chamber 37 formed in the member 7, and this chamber 37 is communicable through a pipe 38 and past a valve 39 with any suitable source of fluid under pressure such as a compressed air reservoir or pump. The valve 39 is operable by a cam or eccentric 40 to admit air or other fluid under pressure to the central passage 33 in the knock-out rod 32 whenever a can 20 has been properly dressed, and providing fluid pressure ejection is being utilized either alone or in connection with mechanical ejection. If no fluid pressure can ejection is being employed, the cam 40 may be disconnected from its driving source; and when no mechanical ejection is being used, the knock-out rod 32 may likewise be disconnected from its driving source; but in case both types of ejection are utilized,

2,576,104 both the valve 39 and the rod 32 should -be periodically actuated at properly timed intervals.

The final can removing plunger 34 which is movable horizontally transversely of the direction of movement of the injector plunger 30, and over the top of the can supporting block 29, may be reciprocated in any suitable manner and at properly timed intervals, so as to simultaneously sweep the-successive finally trimmed cans 20 off of the block 29 and to advance the successive untrimmed cans which drop upon the block 29. The successive-new cans 20 drop by gravity into alinement with the plunger 34 whenever the latter has been retracted and a new can 20 is being pushed onto the plug 18 by the other plunger 30. The successive finished cans 30 may be allowed to drop through an opening 42 in the base 6, or they may be otherwise removed,, and it will'be noted that when the successive untrimmed cans are delivered to the machine by gravity from an upright supply chute 28, the can stack is supported either by the can removing plunger. 34 during presentation of a new can, or by the supporting block 29 as in Fig. 2 whenever a can is being trimmed. The timing of the plungers 30, 34 and of the knock-out devices must therefore be such that no interference between parts results, and the various operations should be effected automatically and. in rapid succession in order to permit high speed and effective trimming of at least one hundred cans per minute.

While the normal operation of the improved can trimming unit should be apparent from the foregoing detailed description of its construction, a short resume will be given.. When the machine has been properly equipped with a plug 18 and chuck jaws 23 of suitable shapes and sizes, and untrimmed cans 28 are being supplied by the can chute 28, the sheave 10 may be rotated to revolve the cutters 16 and the mechanisms for actuating the knock-out rod 32, the plungers 30, 34 and the valve 39 should be set in motion. The injector plunger 30 will 'then push each of the successive cans 20 which are deposited upon the block 29 over the fixed plug or core 18 and between the jaws 23, thereby causing the rough brims or edges of the cans 20 to enter the path of revolution of the knives 16. As these can edges advance into the cutting zone, they are sheared off in helical formation until the bottom surface of each can engages the adjacent end of the plug 18 and the can motion is arrested, whereupon the trimming operation will have been completed. The snug fitting core 18 insures smooth finishing at the brim edge of each can 20, and prevents undesirable distortion of the cans, and the sharp revolving cutters 16 gradually slice off the excess material without tearing or burring the edges.

After a cut has been completed, the injector plunger 30 is promptly Withdrawn, and immediately thereafter the knock-out devices are actuated. If mechanical removal is utilized alone, no fluid under pressure is admitted through the passage 33 in the knock-out rod 32, but this rod is merely moved toward the finished can 20 and pushes the latter off of the plug 18 onto the block 29 and toward the retreating plunger 30. If fluid pressure removal is employed alone, the knockout rod 32 will not be moved, but will remain in the position shown in Fig. 1, while the valve 39 will be actuated by the cam 40 to admit fluid under pressure from the source through the pipe 38, chamber 37, ports 3.6 and passage 33 to the can interior, thereby likewise shifting the finished can off of the plug 18 and onto the block 29 toward the retreating plunger 30. In cases where both mechanical and fluid pressure removal is desired, both the knock-out rod 32 and the valve 39 will be actuated simultaneously, thereby obtaining joint action during ejection of the completed cans 20 from the cutting zone.

When the successive finished cans 20 have been completely removed from the plug 18 and chuck jaWs 23, the valve 39 should be closed, and the rod 32 should be quickly withdrawn from within each can, whereupon the fluid under pressure will escape from the can interior, and the final ejector plunger 34 may be actuated to sweep the finished articles from the block 2 9. After each such final delivery of a completed can 20, the plunger 34 will be quickly withdrawn to permit the lowest unfinished can 20 in the chute 28 to drop into proper position upon the cleared supporting block 29, and the previously finished cans 20 will drop through the opening 42, while the plunger 30 again becomes active to promptly inject the new properly positioned can into the cutting zone. The successive steps of the improved method are thus quickly and automatically repeated so as to accurately and effectively trim the cans 20 in rapid succession.

From the foregoing detailed description of the construction and operation of the unit, It will be apparent that my invention provides an improved method of and apparatus for rapidly and effectively trimming cans or other cup-shaped receptacles, without distorting or otherwise damaging the articles. The invention is applicable to cans or other receptacles of various sizes and shapes, formed of metal, plastic, stiff paper, or other sheet-like material, and the improved mechanism is adapted to automatically perform the successive steps of the method both positively and safely. Either mechanical removal, or fluid pressure ejection, or both types of knock-out may be utilized at the will of the operator; and while the unit is extremely simple and compact in construction, it still has enormous capacity and requires minimum attention. The invention has gone into highly successful and satisfactory commercial use, and is obviously very flexible in its adaptations; and the improved units may be manufactured and operated at moderate cost for diverse uses.

It is also noteworthy that the various parts of the improved mechanism should be formed of suitable wear-resistant materials and properly lubricated so as to insure long life, and the ends of the plugs 18 nearest the knives 16 may be hardened or faced with a hardened plate so as to guard against excessive wear, while the antifriction or ball bearings also reduce the power consumption to a minimum. It should also be apparent that any other method of feeding the untrimmed cans onto the block 29 may be utilized, as for example, the well-known type of curved can Chute 28 which delivers the cans 20 laterally onto the supporting block 29 and causes the newly presented cans to push the finished cans off of this block, thereby eliminating the use of the plunger 34. The use of the plunger 34 for simultaneously removing the finished cans 20 and for presenting or positioning the new cans in proper alinement with the plug 18, however insures perfect positioning of the successive receptacles in line with the feed plunger 30, thereby assuring reliable functioning or performance of the mechanism at high, speed. Such modifications of unimportant parts of the mechanism are obvious to those skilled in the art, but the helical shearing of the excess metal at the can brims by feeding the cans gradually into the path of the rapidly revolving cutters is an important feature which has contributed to the success of my invention.

It should be understood that it is not desired to limit this invention to the exact details of construction or to the precise steps of the method, herein shown and described, for various modifications within the scope of the appended claims may occur to persons skilled in the art. It is also contemplated that specific terms used herein be given the broadest possible interpretation consistent with the objects and purposes of the invention, and that the term “can” shall include any cup-shaped or tubular receptacle formed of any material.