US2522383A - Can opener - Google Patents

Description

J. LAMPL CAN OPENER sept. 12, 195o 2 Sheets-Sheet 1 Fld Sept. 23, 1946 IMI/ENTOR. doser L10/MP1.

N Jv n @on sept. 12, 195o J. LAMPL.

CAN QPENER 2 Sheets-Sheet 2 Filed Sept. 23, 1946 INVENTOR. doser LAMPI.

TTORNEYS.

Patented Sept. l2, 1950 -UNITED STATES PATENT OFFICE A asians. i v CAN OPENERl Y Josef LampLLos Angeles, Calif., assignor to National Machine Engineers,fLos Angeles, Calif.,

l acorporationofCalifornia vApplication September 23,1946, Serial No. 698,826

(c1. so-m v 7 Claims.

' "This invention relates fparticularly to improvements in can openersof -thesemiautomatic type wherein a gripping and ycuttingmechanism is automatically operable or :'releasable. by the appropriate movement of an patent application for Can Opener, Serial No.;

:597,1'76, filed June 2, 1945, and is a Icontinuation lin. part of said application. In said co-pending `e`.p1`3lication the'initial rotation'of an' operating handle. in a given direction actuates an approfpriate mechanism, and causes a primary engage,- ment of the lip of a can between a suitably ser- ."rated rollerand a cutter, While a furtherrota- Ction of the handle in the same direction operfates to shear the vlid from a can. On the other hand, rotation'of said handle in a reverse direction initially operates said mechanism to move the serrated wheel and cutter apart ina manner to release the lip of the can from its cutting engagement therebetween.

They mechanism above vreferred toand described hereinafter generallyy comprises a full gear .rotatably securedy to the operating handle and. a mutilated gear positioned toy mesh'with the full gear during the initialphase ofthe rotation ofthe handle and full gear in either'a driving or releasing direction. lThev handle* is `directly connected with the serrated roller while the mutilated gear is indirectly connectedito the serrated wheel through an eccentric bearingfand lever which initially operate .to raise andX lower the serrated wheel relative to the cutter depending upon the direction ofrotation of the driving handle. i

It is intended iin the-` instant invention torprovide certain improvements for application. to a `can opener of the general type disclosed in said co-pending application orto can openers utilizing equivalent devices to perform thefxsa'me .-functions. These improvements are intended to rease th'e operationof the can yopener'and,gamlong other things, =11o-furnish a` plurality of `resilient `connections between the 'can and the operative can-engaging mechanism of the can opener.

It frequentlyoccurs in. can openers oir-conventional constructionxthat thegcuttin'g and.y

Buteven after :such an exact to can openers and more upon which the cutting parts are located and showing these parts in an open position. z

. lFigure'Z -is an elevational view of the can .opener taken from the opposite side of Figure-1,

2 positioning of the can, the cutting and driving 'elements tend yto `jam and stick against the can bead or' cause the can to tilt, largely due to ir,- regularities in the can surfaces and the lack of adequate compensation for these conditions in the ycan opener.

Itistherefore an object of this invention to provide, in a can opener of the character described, a driving wheel mounted for yieldable can-cutting movement in` a vertical direction.

It is another object to provide a new and improved mounting for a serrated driving `wheel by means vof ywhich said Wheel is yieldable later,

' ally .during a can-cutting operation.

A furthervobject is to'provide a new and improved 'can' opener in which both the cutting and driving elements are yieldably mountedV for movement in `a vertical aswell as a horizontal ,direction so as to provide a substantially floating, can-cutting apparatus. f .l Another object' is-,to provide a new and yim- "proved can opener of the desired character'derscribed iny which` a cutting wheel is resiliently .mounted for relative axial or wobbling move:-

ment with respect to its associated apparatus.

,It is afurther object toprovide a can opener of new and improved construction characterized .A still further object is to provide a new and .improvedv substantially fool-proof means adaptable for the yieldable accommodation of cansof any'conventional size and designed to prevent sticking orjamming of the cutting parts crun- ,due tilting of the can.`

Another further object is to provide a can opener having new and improved self-aligning 'features and which is susceptible of economical reproduction byy conventional mass production methods.

Other objects and advantages will appear Aand be4v brought out more fully from the following descrip-tion considered with reference to the accompanying drawings throughout which like partsv are.v designated by like numerals. Y

Inthe drawings: f Figure 1 is an'elevational view of a can opener embodying this invention illustrating the side parts jbeng cut away.

`fully appears. `tends upwardly at an angle to the pla-ne of said Figure 3 is a view similar to Figure 2 with the parts disposed in another operative position.

Figure 4 is a vertical, sectional view on the line 4-4 of Figure l.

Figure 5 is a view similar to Figure l, parts of the supporting bracket being cut away and the handle and operative parts being shown in a closed or can-cutting position.

Figure 6 is a fragmentary, detailed View of the cutter and its mounting.

Figure 7 is a detailed sectional elevational View on the line 1*-1 of Figure l.

Figure 8 is a plan sectional View on the line 8 8 of Figure 1.

Figure 9 is a vertical sectional view on the line 9--9 of Figure 1.

Referring more particularly to the drawings, I show an elongated can opener frame I I pivotally mounted by means of pins I2 to a wall bracket I3 which may be secured to a Wall I4, as by means of screws I5. Saidfrarne has a cutout portion I6 providing an upper leg l1 and a lower leg I8 which may be bent into bearing sleeves I2 for engagement with the pins I2 so as to provide a sturdy vertical pivotal sup-port for the can opener. Said frame is further provided with a fixed shouldered pin I9, a hole 29 for the obital oscillation of a shaft 2l, and circular hole 22 between said pin I9 and said hole 29 for rotatable confinement of an annular eccentric disk 23 as hereinafter more An ear '24 on said frame I I exframe and provides a fixed support for a freely rotating cutting wheel 25, while anges 21, and 29, stuck out from the frame, serve to strengthen it. The flanges 21 and 29 also serve, in cooperation with resilient structures hereinafter described, as can-positioning guides to hold a can in correct alignment with the cutting wheel 2S. An optional hook. bottle opener 39 may be formed in the lower portion of the frame.

A lever 3l is oscillatably mounted at one of its ends on the pin I9 through a slot 32 in said lever 3|. Said lever 3l is further journalled between its ends upon an eccentric bearing pin 33 aixed to the eccentric disk 23 rotatably mounted in the frame Il so that the rotation of said disk 23 imparts an orbital up-and-down motion to the right-hand end of the lever 3l, as best illustrated in Figures l and 5. The movement of the lever 3I resembles that of' a connecting rod between a piston and crankshaft in an engine but is restricted, for reasons which will hereafter appear, to less than a complete revolution of the disk 23.

A handle 34 is mounted upon a crank 35 keyed to Ithe shaft 2 I. Said shaft 2 I is rotatably mounted in the right-hand end of said lever 3I and extends through the hole 29 for orbital rotation therein. Keyed to the shaft 2 I, in addition to the crank 35, is a full gear 3S, a cam 3'1 and a serrated wheel 38.

Eccentrically and rigidly affixed to said eccentric disk 23 is a mutilated gear 39 adapted to mesh with the full gear 35 during certain operating cycles.

It will now appear that the rotation of the crank 35 in either direction will, if said gears 36 and 39 are in mesh, cause the mutilated gear 39 and the eccentric disk 23 to rotate, thereby rotating the eccentric bearing pin 33 and oscillating the lever 3l so as to orbitally raise or lower the shaft 2i within the hole 29. The mutilated gear '39, being eccentrically mounted upon the eccentric disk 23, in like manner to the lever 3|, oscillates in unison with the lever 3| and thereby retains a substantially fixed center-to-center relationship to the full gear 36 which is carried by the lever 3|.

The cutting wheel 25 is rotatably mounted on a stud 49 seated in the ear 24 of the frame II at an angle with respect to the plane of the serrated wheel 39, and with the cutting edge 4I of the cutting wheel 26 adjacent to the outer edge of said serrated wheel 38 when the serrated wheel is in its uppermost position.

Pivotally mounted upon the mutilated gear 39 (Figures 2 and 3) by means of a pin 42, I provide a pawl 43. A spring 44 is mounted in a slotted pin 45 also on the gear 39 against which pin one end 46 of the pawl is normally urged. by the spring. The other end 41 of the pawl projects beyond the teeth at one end of the mutilated gear 39. At the other end of the mutilated gear yprovide an enlarged tooth or stop 49 which prevents the clockwise rotation of the mutilated gear or the counter-clockwise rotation of the full gear beyond their position shown in Figure 2. A vstop 49 is secured in the frame II diametrically opposite the position of the enlarged tooth 48 shown in Figure 2 for limiting the counter-clockwise rotation of the mutilated gear by the engagement of said enlarged tooth 48 with said stop 49, as shown in Figure 3.

The cam 31, which is keyed to the shaft 2l, lies in the plane of the pawl 43 so that a clockwise rotation of the handle 34 (Figure 2) initially causes the mutilated gear 39 to run oli of the full gear 33, and subsequently causes the cam 31 to engage the back 59 of the pawl and to flex the spring 44 thereby permitting the cam 31 to slip past said pawl 43 at each successive clockwise revolution of the crank. The enlarged tooth 48 meanwhile holds the mutilated gear 39 against further counter-clockwise rotation due to the engagement of said tooth with the stop 49.

A counter-clockwise rotation of the crank turns the full gear 33 and hence the cam 31 into the position shown in Figure 3 wherein the cam face 5I has engaged the end 41 of the pawl. Continued countereclockwise rotation of the crank brings about an inter-engagement of the gears 35 and 39 and a clockwise rotation of the mutilated gear 39 until the enlarged tooth 48 on said mutilated gear engages the full gear 3S thereby preventing further clockwise rotation of said mutilated gear (Figure 2).

A cover 52, of a size and shape suitable for covering the gears 36 and 39 and their associated mechanism, may be -provided upon the side of the frame opposite from the serrated wheel 38 to protect the gears, the cam 31, and the pawl 43, and to avoid possible injury to the fingers of an operator. Said cover 52 has a hole (not shown) to accommodate the shaft ZI. A thrust washer 54 for the crank 35 preferably is provided between said cover and said crank. The cover 52 may be secured to the frame II as by screws 55.

To removably secure the frame I I on the pins I 2,'I provide a hook-shaped latch 56 pivoted to the frame II by a pin 51. Said latch may engage a slot 58 formed in an ear of the bracket I3 whereby the frame II is adjustably held in a desired position of extension from the Ywall I4 and also may be releasably locked against vertical movement upon said pins I2. A ngerpiece 59 aids the manipulation of said latch 55. The frame II may be swung parallel with the wall I4 when said latch 56 is released from engagement with the slot 58.

f""The"aXes` of the cuttingfwheel pinfand-the 'driving wheel pin` orshaft' arel preferablyl inclinedftoward one `lanother at 'approximately 30" includedangle, Vbutat least greater than 0 and tnot more than about l The'par'ts'an'd their relationship' 'described up 'to this pointare similar to those in vvmy applicanon, sensi No. 597,176, and for continuity, and to 'render "easierfan understanding of the im- ''prevernents'l tofwhichthe present application is ipa rticula'rly directed, Iwill'next describe the operation of the'de'vic'e as thus far set forth.

f {'jrhe`hand1es4jis'turned to its limit of counter-I clockwise rotation-as shown in Figure 2, 'thusgear 39 in' alco-unter-clockwise direction untilthe cutting'wheel`26 andthe serrated wheel 3B are in can-cutting position, whereupon said mutilated gearruns off the full gear 35, just as the 'enlarged'tooth 48" engages the stop 49 to prevent the *continuedcounter-clockwise rotation of said mutilated gear. Continued clockwise rotation l'ofthe handle rotates the serrated wheel 38 which carries the edge ofthe can with it for cutting -engagement with ,said cutting wheel 26. At each successive clockwise rotation of the handle 3,4 the cam 37 slips by the back 52 of the paw] 43 by, depressing thespring 44 in a counter-clockwise direction. g I d' fr u pon completion of the. cuttingV operation, the lid having been severed from the can, the handleis given encounter-'clockwise rotation as ,heretofore described', resulting in the l*spacing `of the'serrated wheel 38 from the cuttingwheel 25, v

whereby thelip ofthe can is releasedl f y Just before fthe lid of the can is completely severed, 'said lid is tilted'upwardlyso as to be readily Igraspedv by virtue of the novel relationship between the cutting edge 4| of the wheel 26 and the4 serrated wheel 38. The cutting wheel 26 lis disposed at an'angle to lthe plane of the serrated wheel 38 as'hereinbefore noted. The axis of the cutting wheel is preferably offset slightly from that lof the serrated wheel when the latter v`is in cuttingposition.l By this arrangement the cutting edge 4| bears down upon the top'of the can lid adjacent to the cutting area-slightly rear- 4'wardly of they tangential contact of the can lip with the serrated wheel. The edge of the 'lid is thereby pushed downwardly by the inclined faces of the cutting edge 4I tending to tilt the lid upwardly sd that it may `be readily grasped before the completionv of the cutting operation. AThe cutting wheel 26 should have suicient thickness 'and the angle of the cutting edge should be sufficiently great to prevent the jamming and binding of the cutting wheel during the cutting operation. The proportions illustrated have been found satisfactory.

' l It should be noted that the movement of the serrated wheel 38 towards the cutting wheel 25, in the" initial clockwise rotation of the crank 35, is not a straight-line but a curved-line movement, wherein the serrated wheel is swung upwardly towards the cutting wheel at the same time the serrated wheel is turning, thereby gripping the under side of the can lip and moving the can into operative proximity to the cutting wheel. The resultant of these curved-line and rolling movements is a smooth, progressive, initial can-piercing operation which is achieved by a minimum of effort.

Thusfar this description has been concerned with the basic form of my can opener essentially as shown and described in the co-pending application hereinabove referred to. The improvements comprising the subject matter of the instant application broadly comprise a spring generally designated by the numeral |93 and its associated structure, an offset spring-like section 230 in the lever 3|, a spring 300 associated with the cutting wheel 26 including its cooperating structures, and a spring guide 400, as will now be described in greater detail.

Referring first to the spring modication |00 associated with the lever 3|, said lever is formed with a slot 32, as above noted, such that the pin' I9 can move longitudinally therein. In utilizing the spring |00 said slot is made substantially wider than the shank of the :pin |9 thereby permitting a predetermined degree of vertical tilting movement of the lever on the bearing pin 33. To this end, the frame may be formed with an outwardly extending ear |0| having a downwardly extending lug |Il2, and the corresponding upper edge of the lever may be similarly formed with an upwardly extending lug |03. The spring |00 encircles these two lugs and is normally held in a condition of compression therebetween in such a manner that the left-hand end of the lever 3|, as illustrated in Figures l and 5, is normally forced downwardly to hold the uppermost edge |04 of the slot against the pin i9. Therefore, a downward pressure upon the-serrated wheel acting to remove the same awayl from the cutting wheel will be required to further compress the coil spring' lIlIJ. Such a movement may occur whenever the cutting lip of a can has anincreased vertical thickness or similar irregularity. The tension of the spring |06 may be sovadjusted that. the` normal cutting operation ofthe can opener may be carried out with the spring in its extended position normally forcing the upper edge IM of the slot against the pin I9 and so that only the exceptional strain or stress of a vertically thickened seam'will serve to further compress the spring IIlo or force the bottom edge |05 of the slot towards the shank of the pin I9. In a properly proportioned can opener, the bottom edge'of the slot should never quite engage the pin I9 during a can-cutting operation.

Referring now to the spring form of the lever 3|, an offset generally designated by the nun meral 29|) may be formed as by a double bend or by a simple kick to properly space the righthand end ofthe lever carrying the lserrated wheel outwardly from the plane of the'body of the can opener, preferably though not necessarily at an angle to the frame. The lever 3| is preferably made `of spring steel or like material but if desired it may be tempered only at and adjacent the offset portion 209.

cutting wheel as, when the lip of a can contains any transverse thickening or irregularity such as a transversely thickened bead or seam. KNormally the lever is spaced from the frame to This construction of vthe lever permitskthe serratedy wheel 3BA to move horizontally away from the 7, retain the serrated and cutting wheels axially apart a distance approximately equal to a double thickness of the material of which the can is made so as to approximate the thickness of a can lip in which no abnormal thickening exists. It is within the contemplation of this invention, however, normally to position the serrated wheel substantially against the inner cutting edge 295 of the cutting wheel so that any conventional can lip is pinched between the cutter and the serrated wheel while being cut. It will be seen, therefore, that this latter construction of the lever provides the serrated wheel and the cutting wheel with a resilient tolerance in a horizontal direction in a manner to compensate for the irregularities in the lip of a can due to variations in its thickness. Moreover the combination of the springs lili? and 203 allow a can to float between the cutting and serrated wheels in a vertical as well as a horizontal direction.

The cutting wheel 2S, as most clearly illustrated in Figure 6, is mounted upon a pin it optionally extending entirely therethrough and formed with a head 30! on the opposite side of the frame '24 from the said cutting wheel. On the end adjacent `the frame 2li this pin is provided with a Shoulder 302 which may be either loosely or xedly associated with the pin by keying or pressing. An annular shoulder or washer 303 also encircles the pin and is spaced from the shoulder 302 so that the cutting wheel 28 may move axially or wobble upon its pin to a limited extent.

Coil spring 300 encircles the shoulder 302, the

washer 303, and the shaft of the cutting wheel 2t and normally urges the cutting wheel axially away from the ear 24 of the frame upon which it is mounted. A certain amount of play is provided in the shaft of the cutting wheel so that the wheel is free to move to a limited extent laterally thereby providing a variable clearance between the cutting wheel and the serrated wheel 38. The purpose of the spring 300 is to hold the cutting wheel 20 in a normal position parallel to the ear 24 during the normal cutting operation, but to allow the cutting wheel to move slightly away from the serrated wheel during the time when the can opener is cutting through the thickened seam of a can, thereby providing greater clearance for the seam between the serrated wheel and the cutting wheel.

Adjacent the cutting wheel 20 and at a point upon the opposite side of said wheel from the guide 21 is a spring guide 400 as most clearly illustrated in Figures 1, 4, 5, and 9. The spring guide comprises a substantially inverted L- shaped member preferably formed of spring steel and secured to the frame by any suitable means such as rivets 430i, and an outwardly extending leg 402 which functions in the manner of a vertically movable guide for the lip and top of a can. In View of the fact that cans of unusually large diameter, for example those having a capacity of one gallon or more, tend to be tipped out of the vertical during a cutting operation the cans tend to stick or jam between the cutting and serrated wheels. The abutment of the top of the can with the underside of the outwardly extending leg 402 is designed to yieldably resist such undesired tipping. Said leg is preferably given a downward slant in order to assist in guiding a can while retaining and urging the same into position against the serrated wheel and inwardly towards the frame at that point. Such an action is found to improve and facilitate the cutting of the can.

By the addition of the springs |00, 200, 300 and 400, and the structures associated with them, the can may in a real sense be said to oat during the entire cutting operation, inasmuch as it is permitted to have a yieldable vertical movement by virtue of the springs 100 and/or 300. Furthermore, the wobbling movement of the cutting wheel and also the lateral or axial movement of the serrated wheel due to the spring structure 200 incorporated in the lever permits resilient lateral movement of these parts and the spring guide 400 further permits a limited degree of deviation of the can from the vertical. Thus a suitable combination of these resilient structures insulates the entire operative mechanism as well as the can against shock and is nicely calculated to compensate for variations in thickness and proportions of the rim of such can. From the operators point of view the can may easily be placed in a cutting position on the can opener without timeconsuming adjustments and without being concerned over whether all parts are in proper relation to each other since all essential operative parts are substantially self-aligning. The handle has been found to revolve with a minimum of effort and a maximum of effectiveness.

While I have herein shown and described my invention in what I have conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of my invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A can opener comprising a supporting frame, a cutter journalled upon the frame, a lever oscillatably mounted upon the frame, and a shaft rotatably mounted on the lever, a crank, a cam, a full gear and a driving wheel keyed to said shaft, an eccentric bearing oscillatably connecting said lever to said supporting frame, a mutilated gear operatively connected to said bearing and engageable with said full gear, a spring urged pawl pivotally mounted on said mutilated gear and engageable with said cam in one direction of rotation of said shaft initially to cause the engagement of said mutilated gear with said full gear, a stop on said mutilated gear, an extension on said supporting frame engageable by said stop to limit the rotation of said mutilated gear in onev direction and said stop being also engageable with said full gear to limit the rotation of said mutilated gear in the opposite direction, and resilient means urging said driving wheel into a proximate relationship with said cutter.

2. A can opener comprising a supporting frame, a cutter journalled upon the frame, a lever oscillatably mounted upon the frame, and a shaft rotatably mounted on the lever, a crank, a cam, a full gear and a driving wheel keyed to said shaft, an eccentric bearing oscillatably connecting said lever to said supporting frame, a mutilated gear operatively connected to said bearing and engageable with said full gear, a spring urged pawl pivotally mounted on said mutilated gear and engageable with said cam in one direction of rotation of said shaft initially to cause the engagement of said mutilated gear with said full gear,

a stop on said mutilated gear, `,an extension on said supporting frame engageable by said stop to limit the rotation of said mutilated gear in one direction and said stop being also engageable with said full gear to limit the rotation of said mutilated gear in the opposite direction, and resilient means urging said driving wheel into a proximate relationship with said cutter, said lever having a spring action normally urging the driving wheel axially outwardly away from the frame and being oiset in its body portion in a manner to carry the end of the lever most proximate to the cutter outwardly from, but substantially parallel to, the frame body.

3. A can opener comprising a supporting frame, a cutter journalled upon the frame, a lever oscillatably mounted upon the frame, and a shaft rotatably mounted on the lever, a crank, a cam, a full gear and a driving wheel keyed to said shaft, an eccentric bearing oscillatably connecting said lever to` said supporting frame, a

mutilated gear operatively connected to said bearing and engageable with said full gear, resilient guide means positioned adjacent the cutter adapted to yieldably hold the top of a can substantially level during a cutting operation.

4. In a can opener comprising a supporting frame, a cutter journalled upon the frame, a lever oscillatably mounted upon the frame, and a shaft rotatably mounted on the lever, a crank, a cam, a full gear and a driving wheel keyed to said shaft, an eccentric bearing oscillatably connecting said lever to said supporting frame, a mutilated gear operatively connected to said bearing and engageable with said full gear, spaced guide arms projecting laterally from said frame at both sides of the cutter, the novelty comprising at least one of said guides normally bearing downwardly upon the top of a can and being vertically flexible in a manner to yieldably hold the bead of the can against the driving wheel.

5. In a can opener of the character described comprising a driving wheel element and a cutter element operatively mounted on a frame for relative radial motion towardsv one another, said driving element being mounted inwardly closer to the frame thanthe cutter element, a lever journalled in the frame, said driving element being rotatably mounted on the lever, means for bringing the driving element and the cutter element into anoperative, can-cutting position, the novelty comprising said lever having a spring normally urging the driving wheel axially outwardly away fromthe frame and against said cutter.

6. In a can opener of the character described comprising a driving wheel element and a cutter element operatively mounted on a frame for re1- ative radial motion towards one another, said driving element being mounted inwardly closer to the frame than the cutter element, a lever journalled in the frame, said driving element being rotatably mounted on the lever, means for bringing the driving element and the cutter element into an operative, can-cutting position, the novelty comprising the journalled connection of the lever and the frame providing relative play in a vertical direction between the cutter and the driving wheel, and resilient means normally urging lsaid driving wheel and Said cutting wheel axially to any extreme of proximity limited by the play in said journalled connection.

7. In a can opener of the character described comprising a driving wheel and a rotative cutter operatively mounted on a frame for relative radial motion towards one another, the improvement comprising: a shaft having said cutter loosely journalled thereon, a iirst resilient means normally urging said cutter towards an end of said shaft outwardly from said frame, a stop limiting the axial movement of' said cutter on said shaft, a lever mounted on said frame for relative longitudinal oscillatory movement, said driving wheel being rotatively mounted on said lever, a second resilient means associated with said lever normally urging said driving wheel outwardly from said frame and normally into a proximate can-cutting relationship with said cutter, a third resilient means associated with said lever adapted to tilt said lever with respect to said frame in a manner to urge said driving wheel radially towards said cutter, said lever having a loose journalled connection with said frame whereby said driving wheel element may be yieldably urged away from said cutter by said third resilient means to an extent limited, and a fourth resilient means extending outwardly from said frame adjacent the cutter adapted to yieldably press a can downwardly against the driving wheel during a cutting operation, all of said resilient means being cooperable to yieldably mount a can in cutting position on said can opener.

JOSEF LAMPL.

REFERENCES CITED The following references are of record in the Iile of this patent:

STATES PATENTS' Number Name Date 2,186,668 Curtis Jan. 9, 1940 2,278,731 Olschewski Apr.y 7, 1942 2,423,221 Berkman July 1, 1947 2,462,416 Nelson Feb. 22, 1949

Images