US2746380A - Marking devices - Google Patents

Description

y 2, 1956 l. s. GOTTSCHO 2,746,380

MARKING DEVICES Filed 001. 16, 1952 3 Sheets-Sheet l IHI INVENTOR. law 5'. 60775010 y 1956 1. s. GOTTSCHO 2,746,380

MARKING DEVICES Filed 001,. 16, 1952 3 Sheets-Sheet 2' My. j m, as f INVENTOR. A? S. GorrSc/m May 22, 1956 Filed Oct. 16, 1952 l. S. GOTTSCHO MARKING DEVICES 3 Sheets-Sheet 3 I /6 g W13 YHJh W 6 g Liz if? o LIZ 62/ 56 d8 INVENTOR. /R/) 5. Gov-S0 1 ATTOIQ/VEY "This invention "relates to improvements in marking devices and is particularly directed to devices for apply- "indidiatocontinuouslyor intermittently moving arti c'les whereinjthefm'arking device is actuatedby the movementofthe articles.

The present invention isparticularly well adapted for United States P t nt 7 markin'g' packages and thelike carried by a continuously moving conveyor and will be described in connection With suh use. However, it is to be understoodthat the devices embodying this invention may be employedin thernarking of'any moving object. o t V ln'ma'rking devices of the .characterindicated, as =here- 't'cifoie made,a rotary printing or imprinting drum or cylinder isemployed h'avingtype or indicia on the pen n ery thereof for-"applying an inked or indented impression to the successive articles as the latter are move d ip'a'st the marking station. The drum is rotated by frictional contact of "each movin article with the drum, and, as

the" article moves out of 'co'ntact'with the drum, the returned to its starting or normal position by spring means. In certain 'of'th'ese devices, a rigid stop is ,pro-

any :relative .movement between the contacting, surfaces vided for limiting the return movement o'ftlie drum so that'when the drum, or a projectionflthereon, engages the rigid'stop 'a'shockis'imparte'd tothe device and this causes vibrations to be produced which result in blurring of theimpres'sion at the start of the next operating cycle, as Well as "causing the devicejto Wear more rapidly.

' In UnitedStates Letters PatenttdIra'S. 'Gottscho and "Kenneth H. Kuett, No. 2,592,558, issued April 15,1952, a return r'n'echanisml'l'as'been disclosed which-includes a resilient brake 'for limiting "the return movement" of {the 2,746,380 Patented M y 22,

article during the initial contact therebetween which causes blurring of 'the impression, applied to the article;

Finally, with the return or repositioning mechanism where- ,to'fore provided, the marking drum continues to rotate so long as,it isin contact with an article. Therefore, if the article to be marked has a length, in the direction o fumovement, which is greater than the circumference of themarking drum, the drum is rotated for more than :one revolution and the marking or iudicia is repeated along the length-of the article. This is particularly sobjectionable .if the length of the article is not a'whole multiple of the circumference of the marking .drum .for, in that event, a 'fragment of -.the marking may be applied to the article. i .Accordingly, .it is .an object of the present invention to provide a marking device of the described character having .an arrangement for returning the marking drum successive articles is relatively small.

.Another object is to ;provide a marking device of the described character having means on the marking drum projecting into the path of an article arriving at" the marking station forengagement by the article :to produce the "initial rotation. of the marking drum while avoiding oftthe article and i Still another object .is eto provide a mar-king device oi": the described character with anarrangement for returning the marking drum to its original position after returned .pos'ition, even though contact with the-article drum after amarking cycle and for aecuratly jpositiom 1 ing the drum forth'e commencement 'of 'the next marking cycle. The "return mechanism therein disclosedhas Lt'he advantage of being capable of repositioning the marking drum whether the preceding fmark'ing cycle ?has required a complete "revolution, several revolutions or only a tram tion. of "a revolution of the marking drum; However,

for return ofthe marking 'drum'toits initial ,pos ition'may,

exceed the period of time available between the instant when the 'trailing end of an article leaves the marking station, and thereby releases the marking drum fforits return movement, and the in'sta'ntwhen the ieaainge a of the article'n'ext in line arrives "at the "marking'station,

Thus, the 'in'arking drum may not have "completed the return movement to itsorigin'al position 'at the time when an article arrives at the'mar'kings'tation for commencementof a ma'rking'cycle so 'that'the marking applied during 'the 's'ubseqnen't cycle will "not be properly registered continues, so that only a single marking s pplied -to each, of .the articles.

A Zfurther object of thepresentinvent-ion is to provide a-rnaiiking device having a.return mechanism with ithe above advantageous characteristics which :issimple Sand inexpensive to manufacture .and reliable in its operation. In accordance with .the ,present invention, a marking device "fulfilling the above .objects may 5 include -a r resilient return mechanism of the .kind disclosed .in United States Letters Patent No. 2,592,558, issued April v15, 1952, -to Ira 'S. .Gottscho and Kenneth .Kuett, .for returning the marking drum .to its originahposition when the articles being marked have lengths, in the direction of move ment, which are substantially smaller than the circurn- 'ference of the marking drum, Further, :the marking drum is .Jformedwith a .smooth' flattened peripheral POI? tion arrangedto .corifront the article-at the marking xstation when lthedmm is in-its original or startingposition. An actuatingarrnds.rockablymounted on the drum to project at one end beyond the flattened peripheral portion of the.marking .drum, and an adjustable abutment of the arm relative ate the drum -in thedireetionoftrotation of the latter forapplying the marking. Resilient relative to the article, Further, if the 'article arriving "at the mark ing 'stati'on m'akescontactf with "the drum before means are connected to the actuating .arm for continuously urging (the arm against the adjustable abutment and the latter is positioned so that the projectingend of the ar'mfis disposed adjacent the trailing endof ithe flattene'd peripheral portion of the drum when thefarm contacts .the abutment. "Thus, an articlearriving" at the marking station engages theprojecting end lot the actuaitinga'rm to rock the'latter, and thearmeitects initial rotation or "the marking drum Ithroug'h its contact. with ilre abutment onf'the l'drum. As'the actuating armmoves outof "the path of'theartiele moving past the maiking inder results from the frictional contact of the periphery of the drum with the moving article. However, when the marking drum completes a full revolution, the fiattened peripheral portion thereof contacts the surface of the article being marked and the latter slides over the flattened peripheral portion which prevents further rotation of the marking drum. When the article is sliding past the flattened peripheral portion of the marking drum, the article depresses the actuating arminto a position within the peripheral confines of the drum and, as the article moves away from the marking station, the actuating arm is again spring urged to its projecting position to be engaged by the leading end of the article next in line for the commencement of a new marking cycle.-

Other and further objects, features and advantages of this invention will be manifest from the following description of an illustrative. embodiment thereof and the accompanying drawings, wherein:

Fig. 1 is a top plan view of a marking device embodying the present invention;

Fig. 2 is a side elevational view of the marking device of Fig. 1;

Fig. 3 is a fragmentary plan view, 011 an enlarged scale, of the marking drum and associated mechanism included in the device of Fig. 1, with a part of a side of the drum being broken away to expose the internal mechanism;

Fig. 4 is a sectional view taken along line 44 of during various phases in the operating cycle of thedevice embodying the present invention.

' Referring to the drawings in detail, and initially to Figs. 1 to 4, inclusive, there is shown a marking device, generally indicated by the reference numeral 10, which is constructed in accordance with an embodiment of the present invention. The marking device 10 is associated with a conventional conveyor 12 on which articles 14a and 14b to be marked are conveyed past the marking device disposed at one side of the conveyor. While the marking device 10 is illustrated as being arranged to mark a side surface of each of the successive articles, it is to be understood that the present invention may be applied as well to devices for marking the top or bottom surfaces of the articles. A vertically extending back board or guide 16 may be provided adjacent the cona ball bearing assemblies 20 (Fig. 4) on a vertical stub shaft 22. The shaft 22 is received in a bore 24 formed in one end of a support arm 26 and is secured relative to the arm by a set-screw 28. The opposite end of the support arm 26 is swingably mounted on a vertical shaft 30 which is supported by a suitable structural element outer surface, carries suitable means, forexample, a resilient grooved assembly 44 (Fig. 2), for securing type or indicia thereto. Preferably, the outer periphery of each of the top and bottom end plates is of a diameter only slightly smaller than that of the raised portions of the type or indicia, so that the peripheries are frictionally engaged by the articles to effect rotation of the drum, and frictional engagement by the type or indicia to rotate the drum is not relied upon, thus eliminating blurring LQI the impression applied to the articles resulting from slippage between the type or indicia and the articles. To further reduce the possibility of slippage between the type or indicia and the articles, the peripheries of the top and bottom end plates .38 and 40 are preferably milled or knurled, as indicated at 46 in Fig. 2, thereby increasing the frictional contact with the articles.

In order to limit the swinging movement of the support arm 26 in the direction toward the conveyer so that the drum 18 will be free to be engaged by the articles without being capable of swinging so far across the conveyor between successive articles as to obstruct the passage of the articles onthe conveyor, 21 finger 48 is secured on the top of shaft 30 and extends radially therefrom to be engaged by an abutment 50 formed on the support arm 26 (Figs. 1 and 2). If desired, the finger 48 may be adjustably secured to the shaft 30, for example, by a set screw (not'shown) so that the limitation on the swinging movement of the arm 26 may be varied to accommodate articles of different widths on the conveyor 12.

When an inkedimpression is to be applied to the successive articles on the conveyor, an inking roller 52 having an internal ink supply source (not shown) is supported on the arm 26 for rotation about an axis parallel to that of the drum 18 and in rolling contact with the type or indicia on the drum whereby rotation of the marking drum effects inking of the type thereon. In accordance with the present invention, a peripheral portion of the marking drum 18 is flattened and covered with a preferably smooth straight plate 54 spanning between the top and bottom end plates 38 and 40. Thus, when the smooth, straight plate 54 is engaged by an articleon the conveyor, the article slips along the plate 54 and rotation of the marking drum is arrested. The flattened portion of the periphery of drum 18 and the plate 54 thereof are arranged so that they are facing toward the conveyor 12 when the drum is in its initial position for commencement of a marking cycle.

In order to provide for the initial rotation of the drum from itsjposition at the commencement of a marking cycle, an actuating arm 56 is provided above the top end plate 38. The actuating arm 56 is swingably mounted adjacent oneend on a bushing 58 (Fig. 4) which is carriedby a bolt 60 extending centrally through the top end plate 38. The free end of the actuating arm 56 travels along a circular are which has a radius substantially equal to the radii of the curved parts of the peripheries of top and bottom end plates 38 and 40.

7 Thus, when the actuating arm 54 is angularly positioned 32 which may be a part of or secured to the conveyor ,7

mechanism, and a torsion spring 34 is interposed between the support arm 26 and the shaft 30 for urging the arm 26 to swing in the direction moving the drum 18 toward the conveyor 12 and into frictional engagement with the articles being moved by the conveyor.

The drum 18 is hollow and in the illustrated construction includes a cylindrical side wall 36 and substantially circular top and bottom end plates 38 and 40 which may be removably secured to the edges of the side wall 36. The bottom wall 40 is formed with an upwardly extending, central hub 42 which receives the outer races of the bearing assemblies 20. The cylindrical wall 36, -on its to extend towardthe flattened peripheral portion of the drum, the free end of the arm 56 projects beyond the plate 54, while the arm 56 is within the peripheral confines of the drum when it is angularly positioned away from said flattened peripheral portion of the drum.

Further, the device embodying the present invention includes an abutment assembly, generally indicated by the reference numeral 62, positioned at the side of the actuating arm 56 facing in the direction of rotation of the drurn 18, as indicated by. the arrows 64 on Figs. 1

' 5 and 3, to limit the swinging of arm 56 relative to drum 18 in the direction of rotation of the latter during the marking operation. The abutment assembly 62'includes ablock 66, secured to the top end plate 38 by suitable fastenings 68, and having a bolt 70 extending threadably therethroughto bear against the arm 56. A nut 72 is preferably provided on the bolt 70 to engage against of a new marking cycle. It is apparent that the arrangement herein described .for attaining theproper positioning of the marking drum ings, the operation of the device described above will now becxpla'ined. Assuming that the articles on the conveyor 12 are being moved past the marking device in the direction of the arrows 80, it will be seen that;

the drum is rotated in a counter-clockwise direction, asviewedon the drawing. As the article 14a (Fig. 5,) moves away from the marking station, that article slides over the flattened peripherial portion of the drum 18, and the actuating arm 56 projects radially beyond that flattened portion into the path of the advancing article 14b next in line which is approaching the markin Fig. and to cause the initial rotation of the drum 18 by reason of the contact between the arm 56 and the abutment assembly 62 on the drum. As the flattened l peripheral portion of the drum 18 moves away from the side of the conveyor, to disengage the arm 56 from v the leading end of the article 14b being marked, th'e side surface of that article engages the *knurled rims of the frictional contact with'the article by the spring 34 (Fig.

l 2) During the phase of operation illustrated by Fig.

7, the type or :indicia carried by the drum apply the marking tothe side surface of the article.

, When the length of the article being marked is greater than the circumference of the drum 18, the trailing end portion offthe article 14b willfstill be disposed adjacent the marking station as the drum completes a full revolution to again position the flattened peripheral portion I station. 'lhus, the front end of the article 14b engages the actuating arm 56 to rock the latten'as shown :Finallwwith the "consumerism embodying the present invention, the marking drum is rotated through only'bne While the described structure operates satisfactorily to return themarking drum to its original position at the end of each marking cycle and to register thedrum with each article at the beginning of the marking cycle so "long as each article ha's a length which is not much smaller than the circumference of the marking drum and the spec'- ing between successive articlesdoes not exceed the length of the flat plate 54 on the drum, difliculties do arise when the described structure is employed 'for the marldn g ot relatively shortarticles or of articles which are Widely spaced apart on the conveyor. Thus, if relatively short articles are being marked, the articles will move out of engagement with the marking drum before "a com lete revolution of the latter has been effected and lthe drum will not be returned to its'original, position. r If the articles are widely spaced apart on the conveyor, the articl'e which has been mark-ed will move *oif the flattened peripheral portion of the drurn before the article next in line has made contact with the projecting end 'of actuating farm 5-6, andthe drum will be free to rotate from its returned l drum, as in Fig. 7, with the drum 18 being-urged into of the drum 18 parallel to the path of the articles 'on the conveyor, as in Fig. 8. Ihus, the trailing end portion of the article will slide along the smooth plate 54 so that no further rotation of the drum is eifected, and the actuating arm 56 will be rocked away from the abutment assembly '62 by the article 14b to a, position :in

. which the free end of arm 56 does .not project beyond the periphery of the drum (Fig; 8) As the trailing end .of the article 1412 moves along the smooth plate 54, 'the'actu'atingarm 56 isreleased by the article (Fig. 9.)

andfis again urged against the abutment assembly 62 with its free end projecting radially beyond the plate 54 and into the path of the leading end of thearticle 14c next inlin'e on the conveyor. Thus, when the article J14'ejreaches themarking station, as in Fig, 10, the drum I'Sfis again properly positioned for the commencement atithe beginning of a marking cycle does not require any great space "between the successivearticles on the condisposed on a conveyor to provideefiicient utilization of Y the conveyor. Further, in the described construction,

the rnarking drum is at rest when an article on the conveyor reaches the marking station and the initial movenie'n't of the drum by the article is achieved through 7 contact against the projecting end of the arm 56 rather than by frictional contact with bearing rims on the drum so that slippage of the article relative to the drum during acceleration of the latteris avoided and blurring or imprtipei' registr' ation of the applied marking ispreventedr marking operation.-

position thereby disturbing the're'gistratio'n of the drum with the article approaching the marking station.

Accordingly, it is preferable to use the structure described above in connection with apparatus as disclosed in United States Letters Patent No. 2,592,558, to Ira S. Gottscho and KennethH. Knet't, issued April 15, 1952', so 'thalt thepatented apparatus will efie'ct thereturn of the drum to its original .positionandwill resiliently hold the drum in that position when the articles are too short or too widely spaced apart for the erfici'ent operation of the deviceherein descrlibedt r Therefore, as shown in Figs. 3 and 4, the "marking device It) .is preferably provided with a stationary bar =82 which is mounted onthe upper end of hired "shat-t 22 and is keyed thereto. The bar 82 has a shoft arm -84 and -'a long arm 86 extending in opposite radial directions from the shaft 22. A pulley 88 is 'ro t atably mounted "oh theshort arm $4 and a similar pulley 90 is rot'altably mounted on a log or boss 9-2 at the interior of the side Wall 35. A resilient-loop 94, which may be in the term of a continuous coil tension spring, engages around the pulleys 88and90"to'continuously urge the drum to a position in *which a single-straight line extends through the axisof rotation of thedrum 1 8 and the axes of "the pulleys '88 and90. l

In adjusting the marking device for operation, the set screw 28 is loosened to permit rotation of shaft-2213115 bar 82 until :a straight line extends through the axis of rotation tot the drum 1 -8 and theatres of the pulleys 88 and 90 when the drum is disposed with its flattened pefiph eral portion parallel to the direction of movement or the articles on the conveyor. The set screw 28 is then'tight .ened, so that the flattened peripheral portion "ofthe drum Will /effect return of the drum to the same position, in the manner herein described, as the position to which the resilient loop *94 returns thedr um, in 'thejmanner set forth in the above mentioned patent. Thus, even though the articles being marked are relatively short, the drum 18 is returned to its original position at the end of each In order 'to arrest movement of the drum upon "its return-to the initial position, resilient brake or stop means are provided, which 'by way of example, may comprise an arcuate spring member 96 having one end secured on the inside 'ot'the s ide wall 36 by a screw 98, and having its other end bent inwardly or the wall (Fig 3).-*T I lre arcua te portion for the spring member 96 is in the path engaged by that arm when the drum is returned to its initial position. Thus, the resilient brake described above will prevent oscillation of the drum when the latter is returned to its original position by the action of the resilient loop 94, and will also prevent drift from that .initial position when the spacing between successive articles on the conveyor exceeds the length of the flattened peripheral portion of the drum.

If relatively short articles are to be marked, so that the articlesv move out of engagement with the marking drum before a complete revolution of the latter has been effected, the use of the apparatus disclosed in United States Letters Patent No. 2,592,558, to Ira S. Gottscho and Kenneth H. Kuett, issued April 15, 1952, may be avoided by providing more than one flattened peripheral portion on the marking drum. The number of flattened peripheral portions on the marking drum corresponds to the relationship between the circumference of the drum and the length of the surface of the article being marked. Thus, if the length of the article being marked is slightly less than one-half the circumference of the marking drum, the marking drum is provided with two diametrically opposed flattened peripheral portions so that a flattened peripheral portion willengage an article being marked as such article reaches and leaves the marking station. It is to -be understood that the marking drum, when pro vided with more than one flattened peripheral portion for the purposes described above, has an actuating arm and abutment assembly associated with each of the flattened peripheral portions and each constructed in the same manner as theparts '56 and 62, respectively, described above. Thus, as each of the articles arrives at the marking station it will engage the actuating arm associated with the fiattened peripheral portion which is then disposed parallel to the'path of travel of the articles and thereby cause initial rotation of the marking drum. Further, as the marked article moves away from the marking station, the trailing end portion of the article will slide over the next fiattened peripheral portion of the marking drum to position the latter for registration with the following article. Thus, relatively short articles can be marked in succession by a marking drum of substantial diameter, and the marking drum will be accurately repositioned at the commencement of each marking operation. A marking drum constructed with a plurality of flattened peripheral portions will, of course, be provided with marking elements disposed between successive flattened peripheral portions so that a marking drum having two flattened peripheral portions will carry two sets of marking elements.

In view of the foregoing description, it will beseen that the present invention provides an improved marking device of the character indicated which operates efliciently and reliably to mark articles of different sizes and of different spacing on the conveyor, and which is simple and economical in construction. The device can withstand long and continued usage Without requiring maintenance or repair.

While a preferred embodiment of the invention has i been illustrated and described, it is to be understood that riphery thereof, said drum having a fiat peripheral portion which acts to arrest rotation of the drum when slidably engaged by an article, means rotatably supporting said drum at the marking station for contact at its periphery with the successive articles, said supporting means being movable toward and away from the path of the articles, yieldable means urging said supporting means in the direction toward the path of the article so that peripheral contact of said drum with the successive articles is maintained as the flat peripheral portion and the remaining arcuate peripheral portion of said drum are-disposed for contact with the article, an arm rockably mounted on said drum and extending radially from the axis of rotation of said drum a distance substantially equal to the radius of the curved peripheral portion of said drum so that said arm projects radially beyond said flat peripheral portion when it is disposed within the angular limits of said flat peripheral portion, stop means on said drum for limiting the rocking of said arm relative to said drum in the direction of rotation of the latter during marking of the articles, said stop means being disposed so that said arm, when engaged thereby, is positioned within said angular limits of the flat peripheral portion and adjacent the trailing end of the latter, and yieldable means acting on said arm to continuously urge the latter against said stop means so that, as an article approaches the drum along a path parallel to the flattened peripheral portion of the latter, the article engages said arm disposed against said stop means and moves the arm before the article to effect initial rotation of said drum.'

2. In a marking device of the class described; the combination according to claim 1, wherein said flat peripheral portion of the drum is smooth and the remainder of the periphery of said drum is provided with roughened surfaces so that an article may slip easily relative to the drum when contacted by said flat peripheral portion and so that sufl icient frictional contact is provided when an article engages said remainder of the periphery to effect rotation of said drum without slippage of the article relative to said drum.

3. In a marking device of the class described; the combination according to claim 1, wherein said stop means includes a block fixed on said drum, and a tangential bolt threadedly extending through said block for engagement with said arm so that the limitation on the rocking of said arm may be varied.

4. In a marking device of the class described; the combination according to claim 3, wherein said yieldable means acting on the arm includes a tension spring member connected at its opposite ends to said block and to said arm.

5. In a marking device ofthe class describe-d for marking successive articles conveyed past a marking station;

the combination of a marking drum for carrying marking elements on the periphery thereof, said drum having a flat peripheral portion to arrest rotation of the drum when said flat peripheral portion is engaged by an article, a support arm, means carrying said support arm for swinging about one end thereof toward and away from the path of thesuccessive articles, means rotatably mounting said drum on the other end of said support arm, yieldable means acting on said support arm to continuously urge said other end thereof in the direction toward the path of the articles so that the axis of rotation of the drum is displaced laterally of the path of the articles for maintaining contact of the drum with the articles as the flat and arcuate peripheral portions of the drum move into position for contactwith the articles, article engageable means carried by said drum and yieldably projecting in the radial direction beyond said flat peripheral portion adjacent the trailing end of the latter to be engaged by the leading ends of the successive articles, and stop means engaged by said article engageable means in the projecting position of the latter to limit the movement of the article engageable means relative to sai-d'drum in the direction of rotation of the latter so that the engagement of an article with said article engageable means is effective to produce initial rotation of said drum,

6. Ina marking device of the class described; the combination according to claim 5, wherein said article engageable means includes a radial arm, means mounting the inner end of said radial arm on said drum for rocking relative to the latter about an axis concentric with the axis of rotation of said drum, said arm having a radial dimension 'substantially equal to the radius of the curved peripheral portion of said drum, spring means causing said radial arm to swing relative to 'said drum in the direction of the normal rotation of the latter, and said stop means is locatedon said drum and limits the swinging of the arm in said direction to a position in which the outer end of said arm is adjacent and projects radially beyond .said trailing end of the flat peripheral portion. 7. In a marking device of the class described for mark- 1 ing successive articles; thejcomb ination of a marking station, a marking drum carrying marking elements on the periphery thereof, means rotatably supporting said drum at the marking station for peripheral contact with the successive articles so that the latter act to rotate the drum while the marking elements on the drum apply markings to the articles, means on a peripheral portion of said drum rest rotation of said drum during such contact, means continuously urging said drum in the direction toward the articles so that the drum is maintained in peripheral contact with the articles throughout its rotation, retractable means yieldably projecting beyond the periphery of the drum at said chordal plane thereof for contact by the successive articles to elfect initial rotation of the drum,

means continuously urging said drum to a predetermined rotational position in which said retractable means is disposed for contact with the articles, and stop means limiting the movement of said retractable means relative to said drum in the direction of normal rotation of the latter so that the engagement of said retractable means by an article is effective tocause the initial rotation of said drum.

8. In a marking device of the class described for applying markings to successive articles conveyed past a marking station; the combination of a marking drum having a flattened peripheral portion and adapted to carry marking means onthe remaining arcuate peripheral portion thereof, means rotatably supporting said drum at the marking station for movementtoward and away from the path of the successive articles, means yieldably urging said drum in the direction toward the path of the-articles said drum and a retracted position included within the defining a chordal plane for contact with the articles to arradial confines of said drum, yieldable means continuously urging said retractable means to its projecting position, and stop means operative when said retractable means is in its projecting position to limit the movement of the retractable means relative to said drum in the direction of rotation of the latter so that the engagement of said retractable means by an article approaching the drum effects initial rotation of the latter.

References Cited the file of this patent UNITED STATES PATENTS 1,596,416 Erickson Aug. 17, 1926 2,130,898 Ogden Sept. 20, 1938 2,443,791 Ielfield June 22, 1948 2,592,558 Gottscho et al Apr. 15, 1952 2,636,436 Mann Apr. 28, 1953 2,664,816

Gibson Jan. 5, 1954

Images