US1960931A - Guard for slicing machines - Google Patents

Description

y 1934- H.\THOMAS 1,960,931

GUARD FOR SLICING MACHINES Filed April 9, 1931 6 Sheets-Sheet l zII/IIIIIzIi/III 31mm,

1723????"07 Henry 2% omaa May 29, 1934.

H. THOMAS GUARD FOR SLICING MACHINES Filed April 9, 1931 6 Sheets-Sheet 2 He2277 2% ama y 29, 1934- H. THOMAS 1,960,931

GUARD FOR SLICING MACHINES Filed April 9, 1931 6 Sheets-Sheet 5 May 29, 1934. H. THOMAS GUARD FOR SLICING MACHINES Filed April 9, 1951 6 Sheets-Sheet 4 fraflerz lie/227 272 02720:;

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May 29, 1934. H. THOMAS GUARD FOR SLICING MACHINES Filed April 9, 1931 6 Sheets-Sheet 6 I7Z067Z Z52 Henry Z7z0ma5 By M Q): Mm!

l atented i i lay 29 1934 GUARD FOR SLICKNG MACHINES Henry Thomas, Barking, England, assignor to U. S. Slicing Machine Company, La Porte, Ind., a corporation of Indiana Application April 9, 1931, Serial No. 528,793 in Great Britain April 9, 1930 9 Claims.

The present invention relates to slicing machines and particularly to work guards which protest the operator from injury by the slicing knife during its rotation. The present invention is adapted particularly for use with power driven slicing machines in which the knife is travelling a rapid rate and usually about an axis eccentric to its own axis of rotation in addition torotating about its own axis. it is very apparent that if the operator-places his hand in a position to be cut by such a knife that irreparable damage will be done before the machine can be stopped.

Qne object of this invention is to arrange guards over the substance support and also over the slice receiving trough so that the operator cannot accidentally bring his hands into a dangerous position with respect to the knives when the guards are in place.

Another object of this invention resides in promeans automatically operable upon movement either of the guards to inoperative posi tion for turnirr oil the power which drives the knife if de ed, providing means for slowing down knife at a more rapid rate than would oro arily occur when the power is shut off. In this manner the knife is brought to rest during the movement of the guard to an inoperative position and there is very little chance that the operator will put his hand in a dangerous position h respeotto the knife until after the knife has been brought to rest.

A more specific object of this invention resides a point where the same is not exposed to view,

being obvious that the casing in which the knife rotaos must be provided with an opening through whi h the substance can be fed, and if the knife comes to rest adjacent this opening the operator may sustain slight injury by placing his hands too Of course, with the knife close to the knife. stopped, no great amount of damage can be done but it is preferable that the knife be stopped in the upper part of the casing where it cannot inlure the operator.

Another object of this invention is to control by suitable electrical means, manually operated, the turning off of the power me'ans'and applying a braking means for slowing down the rotation of knife if and when either of th'eguardsare moved toward inoperative'position.

A still in er object of this invention resides in providinga make for slowing down the rotation of the knife after thep'o'wer has been turned off, this brake beingcontrolled magnetically and automatically whenever one or" the guards is moved to an inoperative position.

ther objects of this invention will appear hereinafter as the description thereof proceeds, the

novel features, arrangements and combinations Fig. 3 is a. section taken on the line 3-3 of Fig. 2.

Fig. i is a section taken substantially along the line 4-4 of Fig. 1.

Fig. 5 is a section taken substantially along the line 5-5 of Fig. 4.

Fig. 6 is a front elevational View of the guard for the slice receiver looking in the same direction as in Fig. 1.

Fig. 7 is a section taken along the line '77 of Fig. 6.

Fig. 8 is a plan View of the mechanism shown in Fig. 6.

Fig. 9 is a cross section taken along thelne 99 of Fig. 7.

Fig. 10 is a diagrammatic View of the wiring system which controls the operation ofthemotor and brake when either of the guards is moved to inoperative positions with the construction as shown in Figs. 1 to 9 inclusive.

' Fig. 11 is a diagrammatic View of the electrical system used" with a modifiedconstruction of my apparatus.

Fig. 12 is an'endelevation of the mechanism looking from the right in Fig. 1, this view being" ane'nlar'ged View of aportion of the mechanism illustrated in Fig. 2.

Fig. 13 is a rear elevational view of the brak- Eng mechanism shown in Fig. 12, and

Fig. 14 is a section taken along the' lin'e 14l4 of Fig; 13.

The slicing machine illustrated in the drawings comprising thebas'e members 1 and-Zwhich support the frame work of the slicing machine. The base member 1- supports the casing 3 which is formed of a plurality of parts and has an opening indicated at 4 in Fig. 4 through which thesubstance' tob'e sliced is passed in' order that the same maybe cut by the slicing knife which is arranged within the housing.

The base 2 supports an upwardly extending bracket 5, which bracket and the housing 3 support a tubular casing 6 in which is rotatably mounted the shaft 7. The shaft 7 at one end thereof, carries a flywheel 8 about which is trained a belt 9. The belt 9 is also trained over the pulley 10 on the rotor shaft of the motor 11 so that rotation of the motor will rotate the flywheel 8 and shaft 7. The motor is mounted on an adjustable bracket 12. The other end of the shaft '7 supports a casting 13 which carries an arm 14, this arm being adapted to carry a knife 15 rotatable about the axis of the shaft 16 upon which it is mounted. The casting 13 is secured tothe shaft '7 by means of the set screw 1'7. The knife 15 rotates about the axis 16 by means of a chain which is trained over a sprocket on the shaft 16 and over a sprocket secured to the shaft 18 which is arranged coaxially with the shaft 7 and assists the shaft 7 in supporting the shaft 16 during its rotation.

When the shaft 7 is driven by the motor, the knife 15 will rotate about its own axis and also about the axis '7 in a manner which is more fully described in the patent to Stukart, No. 1,557,- 893, granted October 20, 1925, except that the knife is driven by means of a chain instead of by gears as in that patent. The chain drive that is adapted to be used with this invention is similar to that illustrated in the co-pending application of Arthur Ahrndt, Serial No. 332,790 filed January 16, 1929. However, my invention is not limited to a chain drive, as the gear drive of Stukart may be used as well. The present invention is in reality not limited to the particular drive for the knife, but has a special advantage in a machine provided with a knife having the orbital movement which has been described and which is more fully discussed in the aforesaid patent and the aforesaid application.

Means is provided for feeding the substance past the cutting plane of the knife so that successive slices will be cut therefrom. This means, as shown in the drawings, is more or less conventional, being more fully shown in the aforesaid patent and application, and comprises a feed screw '19 rotatably mounted in the base members 1 and 2, a guide rod 20, a substance supporting trough 21, and a feed member 22 which has the prongs 23 pivoted at 24 so that the same may be moved into one end of the loaf of bread to be sliced and hold the loaf against the feed member 22 while the same is fed toward the cutting plane of the knife. The guide rod 20 has a bearing member 25 slidable therealong and secured rigidly to the feed member 22. The bearing member 25 also has a feed nut 26 secured thereto which engages the feed screw 19.

The feed screw 19 is given an intermittent movement of rotation by means of a suitable free-wheel 27 connected by the crank 28 to an oscillating arm 29 more fully described in the aforementioned application of Arthur Ahrndt. The feed mechanism is such that as the shaft '7 is given one complete rotation the substance is fed forwardly toward the cutting plane of the knife, the thickness of the slice to be cut. The feed screw is preferably at rest during the passage of the knife through the substance being cut.

Knives used in machines of this character require frequent sharpening in order to keep the same in proper condition and accordingly I provide a knife grinding mechanism indicated generally by the reference numeral 30 and having the grinding wheel 31 and burr removing wheel 32 rotatably mounted thereon. The grinding unit 30 is mounted on a bracket 33 secured to the easing 3 and is adapted in one position of adjustment to occupy the position illustrated in Fig. 1, viz: with the grinders in operative engagement with the edge of the slicing knife.

In Fig. 1 I have shown the grinders in operative position and 1 have also shown a cover 34 which normally closes the opening 35 in the upper part of the casing 3 and prevents injury to the operator when the grinders have been moved to an inoperative position to one side of the casing. This construction is quite well known to those skilled in the art to which this invention pertains. In order to rotate the knife for sharpening the shaft '7 is preferably locked positively in a position such that the knife is in the upper part of the casing 3. The means provided for this purpose comprises a locking bolt adapted to enter an opening 36 in the cam 37, which cam 37 also is provided with a groove which co-operates with the cam roller secured to the arm 29 and causes oscillation of the arm 29 for the purpose of feeding the feed screw as before described. This means is more fully described in the previous patent and application referred to above.

In order to rotate the knife for grinding, I provide a crank 33 secured to the shaft 18 and provided with a handle 39 pivoted to the crank at 40 and normally in the full line position indicated in 1 with the lug 41 thereon arranged between spaced lugs 42 on casing 3 in order that the shaft 18 will remain stationary when the slicing operation is taking place, as otherwise the knife would not rotate positively about its own axis. When the shaf 18 remains stationary the sprocket the spaced lug i2 and permits the operator to turn the crank by means of the handle.

The construction so far described is covered by previous applications and patents of applicants assignees and does not form a part of this invention except in the relations which will hereinafter be pointed out and claimed. 1 will now proceed to describe the novel features of this invention.

Referring more particularly to Figs. 1 and 1 it will be noted that there are a pair of split brackets l3 secured to the tubular casing by means j of the clamping bolts 44 and these ,split brackets 43 have a plurality of rods 45 extending longitudinally of the machine for preventing the operator from having access to the substance on the support 21 from the top and from the rear thereof, as is best seen in Fig. 1. It is necessary, however, that the operator be permitted to have access to the substance support in order to position the substance to be sliced thereon and for this reason. there is pivoted to the brackets 43 at 46, the members 47 which in turn carry a plurality of parallel rods 48 forming a guard which normally hangs down in front of the substance support and prevents the operator from having access thereto and 1 movement by an adjustable stop "secured thereto and abutting-againstoneof the rods 45'.

The guard 49 is providedwith a pin 51 operating within a slot 52 in anarm53piv0ted at 54' to a bracket 55 on the'casing 3'. The arm 53is also pivoted at 56 to an extensible link-57, the details of which will be more fully described hereinafter in connectionwiththe guard for the-slice receiver. connected to the toggle58' of the electrical switch 59.

stance-support and the guard for the slice receiver are. in operative positions.

In- Fig; 10 I have shown-a diagrammatic'ar rangement of'the'electrioal means for'controlling the motor and for controlling a brake which will presently be described, which brake acts on the periphery of the flywheel 8 to stop the rotation of the knife when the power to the motor has been out off. The power circuit is. indicated by the reference numeral 62 which power circuit has the leads 63 and 6% leading to the motor 11, the switches 61; 59 and 60 being interposed in one of the leads. It is obvious that whenever anyone of the switches 59, 60' or 61 is in an inoperative posi-. tion the motor will not operate. Therefore it is necessary thatall switches be in operative position in order for the-slicing machine to function. A'transformer 65connected to the power circuit and rendered inoperative when the circuit to the motor. is. broken, normally induces 'a magnetic pull in the solenoid 87iwhich is of a low voltage type, which solenoid surrounds the rod 88 and exerts a pull on the rod to the left asviewed in Fig. 10 or as viewedin Fig. 2. A spring- 89-surrounding the rod 88 and'abutting against a collar QO'secured to the rod 88 normally urges the rodtothe right by its engagement with the-collar 90 and the-casing 91 in which the solenoid is arranged: The rod 88 vis'connected by a link 92 to one arm -71 of a bell crank, the other arm of the bell crank being in dicated by the reference numeral '70;v The-bellcrank is mounted on a shaft 66 and rotatablein a bearing bracket 67 secured to the bracket 5.. The bell crank'is referred to generally' by the reference numeral 69 and is secured to the shaft 66 by means of the pin '72.

An. arm '73rotatably mounted on theshaft 66- carries'a rod- 74 extending radially'of the shaft 66. A'brake shoe75 is slidably mounted on the rod '74 and a spring '76 surrounds the-rodfand' abuts against the-arm 73' and brake shoe 75 to urge the brake shoe '75 upwardly against the head:

ofthe screw '77 secured-to the end of the'rod '76."

The'bearing 78'which carries the-arm-fl3 also has the plate-like. arm '79 extending, radially from the shaft 66 and this is provided with-a slot 80in which a pin 81 onthe arm 70'is adaptedto operates The brakeshoe '75 is provided'with a bore'82 arranged transversely to the opening in: which the.

rod 74 is slidable'andi'a bolt '83 slides in the bore- 82 and is normally. heldsin' the. position illustrated in. Fig. 12'by a spring 845 which surroundsqthebolt: and: abuts against: the brakexshoe .75 and the head 85!; of ."the .bolt. The outward. movement 10f? The extensible link 5-? is' operatively The switch 59 is connected in the power cir-. cuitof the motorand so arranged thatthe power the bolt'is limited by a lug 86 on the arm -'7'0 The periphery of the flywheel 8 is providedwith arecess 99-forthe'reception of the bolt 83 when-the bell crank 69 is rotatedin'a counter-clockwise direction as viewed in Fig. 12. The arm '79 is provided" with a tongue which operates within a slotlOl' in the side of the brake shoe for a purpose which Will appear presently.

The operation. of the mechanism so far described is asfollowsz" The operator grasps the guard 49'and'moves-thesame to an inoperative position. Inso doing'he turns off theswitch-59" through theintermediary. of the link 57' opera tively connected to the guardand'to the: switchin the manner previously referred to. It is as--- sumed that-priorto the movement of the-guard to its'inoperative position'all of the switches-59; 60 and 61 were closed and the-motor running; The movementof the guard 49 to an inoperative position, of course, causes abreak in the power circuit and the motor will cease to rotate the knife; broken, that to the transformeris also 'broken'and the solenoid 87 will bade-energized, thereby per"- mitting the spring 89 (see particularly Figs. 2 and 10) to move the rod 88 to the right and rotate-the bell crank 69 in a counter-clockwisedirection:

This motion of the crank brings the brake shoe '75 into engagementwith the periphery of the fly wheel 8 thereby slowing downthe motion of'the fiywheel' at a more rapid rate thangvwould ordi narily occur if no decelerating means-were provided. Continued-movement of the-bell crank under the influence-ofthe spring causes-the lug? 86 to move the bolt 83 againstthe action of-the spring 84 through the bore 82 into engagement" with the periphery of the flywheel. As-soon asthe recess 99in the periphery ofthe flywheel comes into aposition to receive'the bolt 83, the

latter will: enter the recess and as a result, the: flywheel will be locked positively against rota The position at which the. flywheel is tion. brought to .rest is preferablythat illustrated'in Fig; l inwhichthe-lmife is in the knife grinding position and out of a-position where an operator could be injured thereby; The shock of suddenly stopping the flywheel '7 by means of the bolt '83-istaken up by thespring '76 whichrpermits'theshoe- 75 to-slide along the bolt 74;:butwhich graduallyabsorbs-the energy which causes the flywheel 8 to' rotate. The tongueand groove connection '100 101 also permits Ithis slidingmovem'entof the brake shoe and forms an :additionalsupport forthe other side ofthe-brake shoe and thereby prevents rotation of a the brake shoe about the rod '74.

In order to start the operation of the machine the switches 59; 60- and- 61 must be closed. In

order that this may occur, the-guards which are connected to the'switches 59 and: fio'must-be'in their operative position and the operator must make sure that the masterswitch 61 isalso turned on. As soon asall threeswitches are inclosed or on position themotor will rotate and the solenoid 8'? will be energized; thereby-draw ing the brake away from the flywheel and per-- mitting the functioning of the machine .in-the manner which has previously been described:

It is obvious that the sliding bolt 83 isnotneces saryto this inventionand therefore may-be done away with as the brake 75 will operate without the necessity of usingthe bolt 83; Whenever the sliding-bolt 83 is' not use=d,:the brake 'shoe'maybe mounted'rigidly uponthe arm 73 instead of slid ably and the other unnecessary parts? of the Since the circuit to the motor has been I mechanism shown in these figures can be done,

away with.

, I will now proceed to describe the guard which guards the slice receiver, this guard being one which is quite similar to that for the substance support and operates in substantially the same manner, except that provision is made for operating the switch 60 whenever the guard for the slice receiver is removed from the slicing machine. As is quite obvious from an inspection of Fig. 1, the guard would prevent the operation of the crank 38 when it is desired to use the crank for the purpose of sharpening the knife. It therefore is quite necessary that the guard be bodily moved to an inoperative position either by pivoting away from its operating position or by removing the same as a Whole by means which will now be described.

The guard for-the slice receiver is best illustrated in Figs. 6, '7, 8 and 9. In these views the slice receiving trough is indicated by the reference numeral 102 to which are secured the brack ets 103 and 104 which are preferably castings. The bracket 103 is a substantially closed figure as illustrated in Fig. '7 and is of substantially the same size as the opening 4 in the casing 3. The bracket 10% extends along the bottom of the slice receiver 102 and along the rear side thereof, as well as over the top. However, it terminates at a relatively low position on the forward side as indicated by the dotted line 105 in Fig. 6. Rods 106 are arranged longitudinally of the slice rec'eiver and are connected to the'brackets 103 and 104. These prevent access to the slice receiver by the operator from a position above or to the rear of the slice receiver. On the brackets 103 and 104 there are pivoted the arms 107 at 108 and bars 109 are secured to each of the arms 107 which form a front guard which may be pivoted to an inoperative position to permit the operator to have access to the slices which have been cut by the slicing knife.

The arm 10'? which is pivoted at 108 to bracket 103 is also provided with a pin 110 which operates within a slot 111 in an arm 112 pivoted at 1.13 to the casing 3. Therefore, as with the guard for the substance support. the free end of the arm 112 is moved upwardly whenever the guard is moved upwardly about its pivot 108. The outer free end of the arm is operatively connected by means of an extensible link 114 to the toggle 115 of the switch 60. This link 114 is constructed the same as the link 5'7 and is extensible for the purpose of permitting lost motion to occur after the .switch 115 has been moved'asmuch as permitted I ment member 122 is also secured to the sleeve 121 so that the sleeve moves bodily with the rod 117 whenever the latter is moved. The arm 112 has a spherical head 123 provided at its free end and this spherical head is arranged between abutg ments 124 secured to the tubular outer casing The outer casing 116 is provided with a slot 116 to permit the tube 116 to move relative to the toggle 115, and also to facilitate the assembly of the tube over the toggle.

When the arm 112 is moved upward, the casing 116 is carried upward therewith and due to the spring 112 the head 119 is kept in engagement with the abutment 124 until the toggle 115 has been moved to the off position for the switch 60. Continued upward movement of the arm 112 will not move the toggle 115 and the spring will be compressed in order to permit the outer casing 116 to slide upward relative to the rod 117.

It is obvious therefore that if either the guard for the substance support or the guard for the slice receiver be moved to an inoperative position one of the switches necessary to complete the circuit to the motor will be thrown to an 01f position andthe slicing machine knife will be stopped, thereby protecting the operator. Whenever the guards are moved back to their operative positions and the master switch 61 is on, then the motor will operate and the slices may be cut in the usual manner.

Means must be provided for turning oil the power to the motor whenever the guard for the slice receiver or whenever the slice receiver and its guard are bodily removed from the slicing machine. This means is also shown in Figs. 6, '7, 8 and 9.

The casing 3 is provided with the lower slice supporting member 125and upwardly extending side flanges 126. To the latter there are secured the bearings 127 and 128, bearing 127 being provided with a bore 129 for the reception of a pin 130 secured to the bracket 103 as best illustrated in Fig. 9. The pin 130 isfreely slidable longitudinally in the bore 129 when such movement is permitted. The bracket 103 is also provided with a pin 131 which has a head 132 thereon. The pin 131 is adapted to rest within the open-sided recess 133 illustrated best perhaps in Fig. '7. The enlarged head of the pin 132 prevents the removal of the pin 131 from the open-sided recess 133 except by movement in an upward direction. In other Words, by pivoting the bracket 103 about the pin 130 the pin 131 may be moved free of the bearing 128 and out of the recess 133 after which a movement of the bracket 103 in a direction longitudinal of the pins 130 and 131 will enable one to entirely detach the bracket 103 and consequently the slice receiving trough 102 from the slicing machine. '3

This is undoubtedly a very simple method of 5 detachably mounting the trough upon the casing 3 of the slicing machine, but of course, it is necessary when removing the slice receiver to provide means which will automatically cause the switch 60 to be turned to its off position so that 130 the motor will be turned off and the brake applied. It is obvious that when the bracket 103 is pivoted in order to remove the pin 131 from the recess 133 the arm 112 will move upwardly since the pin 110 moves bodily upwardly with the bracket 103. This movement of the pin 110 of course will move the switch to its off position in the manner previously described and if the arm 112 can be retained in its upward position and prevented from accidentally being moved downwardly, the desired protection for the operator Will result, for with the switch 60 in its oil posttion the machine cannot operate.

Pivoted to the front flange 126 at 134 is a lever 135 best illustrated in Fig. 6. Surrounding the pivot 134 is a coil spring 136 having one end 137 thereof in a suitable recess in the flange 126 and the other end 138 thereof engaging one end of the lever 135 and bearing on that end to rotate the lever 135 in a clockwise direction about its .50

nee -e311 pivot1134.. The lever 135 is :provided with 3.31310- jection 139 which normally engages thehea'd 132.

of:.the. bolt. 131 when. the. slice receiver issin. its

operative; position. This normally prevents thev rotation of the lever'135 aboutiitspivot.

When they slice receiversis. removed from the: slicing machine the first movement; of. the" pin 131 01.113. oflthe'recess 133:0ausesthe arm 112 to be moved. upwardly to: turn off" the. switchfii); The. head of1thebolt1132 slidesalong the adia',

cent face ofstheilever 135- untilftheheadissfreei from the recess 133' and thebolt: maybe moved.

longitudinally so. that thetslice receiver maybe removedentirely fromthe'machine; Asasoon' as the bo1ti131 is moved out of its position the: spring 136 mayrotate. in a'clockwiserdirection andrbring.

theupper end 1i0v ofthe' lever 135 under the arm 112 toihold the-arm=112 in'its upper position, a

recess 141 being provided to receive the; underside ofthe-lever 112:and hold thelever against downwardmovement'. Since the lever. 112 is pre vented frommoving downwardly 'it sis obvious that the switched cannotbe operated accidentally.

InFig; 4 1twill be noted'that inorder to form an additional'brace for the split brackets-4B there areprovided extensions 142having U shaped recesses 143 therein which extendaover the hollow tubular rod1144- and thesolid rod-1.45;. The latter forms-a brace for connecting the end'memb'ers of the'frame'of the'slicingrmachine. The tubular member 144 forms-a housing for the cable 146 which runs from the switch'6l tothe-switches 59: and.60.

The operation of thisdeviceis quiterobvious; The movement ofeither. of the guardsto an in.- operative' positionwill cause aibreak in the motor circuit and as a'result, themotor 'will'bestoppe'd' andithe brake applied'as referred toparticularlyv in. connection with thediagram'shown in-Fig; It isobvious that'other changes maybe'made in thezspecific arrangement used for'turning ofitthe' motonrbut the embodiment shown xissufficientxto. illustrate one form offmy invention;

In Fig. 11 I- have illustrated a modified: ar

.2- rangement for breaking the motor circuit and stopping the rotationofthe knife. Thisarrangezment is somewhati'the same as-in Fig. 10 but differs therefrom in thatthe wholeioperationtis aue tomatically electrically controlled andit isinot' necessary to provide links'such as the links 52: and 114. Inthis modification the-guard fors'the' substance support or the guard for'thet slice re ceiver is indicated'bythe reference numeral 147. pivoted at 148 and-it will'be understood thatth'e 3 guard is pivoted the same as in the modification which hasbeen described, or in anysotherxsuitable manner. An electrical. contact 149 is pro v-idedonthe frame of the machine; or atamrother suitable place to be contacted by the guardlil'l.

when in-its operativepositiom Theguardand thecontact' 1i9 are connected by leads 1503to a solenoid 151 in which there is arranged a rod 152; This rod is normally. spring pressed to the right bymeans of a spring 153-abutting againstcollar' l5 land a rigid abutment 155'similar't'o theabut ment'91'which is apart of'the casing for enclosing thismechanism. Theright handiendof the rod l'52 is pivoted to a switch 156 which switch is normally adapted to' close the circuittotheimoten 11 The circuit to-the motor includes the leads 7which are tappedoff themain power circuit 158. The'motor'circuit is also provided with-a master switch 159 which corresponds-to the-switchfil shownin:Fig-s; 1' to 10 inclusive.

-. When the switches-159 and 15'6are closedyit is:

notrotate.

The master. switch. 159.:and thesswitch 156 may: be connected together so that when one is open:

the-other willalsobe open,.orthe two switches maybecombined as-one switchso that after the motor has been stopped the circuit maybe closed manually;.foritis obvious thatv the meremovement of the=master switch to-itsclosedposition would notcomplete the circuit to the motor and unless some means were provided forzmovingthe switch 156 to its operative position. there would be no Way for starting the motor 'or for energizing the solenoid 151; Inthe drawings.I havein'dicated the switches 156-and 159' as being connectobvious that: the' motonwill operategbutt when. either?ofzthesez-switchesil59. or 1516iis; openzthe mo? tor cannot operate; andaccordingly'theiknifezwill;

ed by the linlt'lfio'but it is obvious that-other:

methods may be used for tying the switches together in such a mannerthatboth will be closed simultaneously. As already stated, it

wouldnot 'be necessary to have a'separate switch- 159 as'means couldbe'provide'dior manually closing the switch-lfifi and the device would-operate rotated; As soon as thecurrent passes-through the'solenoid-the rod 1521s drawnto the le'ft' and the brake is heldout of operative position-witli' respect to'the flywheel and the switch 15'6and switch 159 "will remain closed Tliesolenoidcircuit is provided with the transformer 161. The arrangement inFig. 1 1' may be adapted' for use withtwo guards-instead of one. That is, theguard for the substance support and'the guard for the slice'receiver maybe arranged in series with each other similar tothe' switches-59; 60 and-61 in Fig. 10-so thatwheneveneither of the guards ismoved toan mop-- erativeposition the circuit will bebrolren and the'slicing knife-'Willbe'stoped, Or, if desired,

only one guard maybe p'rovidedWith-the circuit breaking-means-shownin Fig. 11 and'theother guard be mechanicallyconnected therewith so that when one guard ismoved to-an inoperative position the other guardis also moved to-an inoperative position, thereby insuring that the circuit willbe broken whenever either guard is grasped by the operator and moved to its inoperative position.

lt i's obvious-that'other arrangements could be provided for accomplishing the results disclosed in this-application, and therefore I do not wish to Delimited except in the manner set forth in the appended claims:

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

1'. In a slicing machine, the combination with a knife movable along apredetermined path,

said knife having a slicing position and a-knife sharpening position, a casing for enclosing said knife except at its slicing position andat its knife grinding position, a cover for said knife at its knife grinding position, a guard for preventing access to saidlmife at its slicing position, a'motor for driving said knife, an electrically operated brake automatically operable for stopping rotation of said knife shortly after said motor is rendered inoperative, and means for automatically stopping said knife in its knife grinding position whenever said motor is rendered inoperative.

2. In a slicing machine, the combination with a substance support, of a slice receiver, a knife movable along a fixed path for slicing substances upon said support, a motor for driving said knife, a guard for said slice receiver to prevent access to said knife at its slicing position, said slice receiver and guard being removably mounted on said slicing machine, means automatically operable upon removal of said slice receiver out of its operative position on said slicing machine for rendering said motor inoperative, and a magnetically controlled brake automatically operable for stopping rotation of said knife after said motor is rendered inoperative.

3. A device as claimed in claim 2 in which a means is provided for automatically locking said knife in a position remote from its slicing position when the rotation of said knife is stopped by said brake.

4. In a slicing machine, the combination with a knife movable along a predetermined path, a casing substantially enclosing said knife during its movement along said path except at a slicing position, means for feeding a substance toward the cutting plane of said knife at its slicing position, a motor for driving said knife along its path, a brake automatically actuated for retarding the rotation of said knife when said motor is rendered inoperative, a power circuit for driving said motor, and a plurality of control elements for controlling said circuit, a plurality of guards for preventing access to said knife at its slicing position, operative connections between said guards and said control device, said operative connections being such that when any of said guards are moved to an inoperative position the control device connected thereto will render said power circuit for driving said motor inoperative.

5. A device as claimed in claim 4 in which one of said control devices is a master control device for rendering said power circuit operative or inoperative to drive said motor, and in which there are operative connections between said master control device and the control devices connected to said guards, said connections being such that said master control device is rendered ineffectual to complete said power circuit except when said guards are in operative positions.

6. A slicing machine comprising a rotatable knife, a motor for rotating said knife, a power circuit for said motor including three switches connected in series with said circuit, a pair of guards for operatively guarding said slicing knife so that an operator is protected from said knife when said guards are in operative positions, an operative connection between one of said guards and one of said switches, an operative connection r 7 between the other of said guards and another of said switches, said last two mentioned switches being actuated by their respective guards when the latter are moved toward inoperative positions for rendering said power circuit inoperative, and a connection between said third switch and the other of said switches acting as a master control for said circuit whereby said circuit may be rendered inoperative while said guards are in their operative positions with respect to said knife but being incapable of rendering said circuit operative when either of said guards is in an inoperative position.

7. In a slicing machine, the combination with a slicing knife movable in a predetermined path for severing slices from a substance, a support for the substance to be sliced, a casing over said knife to completely enclose said knife as it moves along its path of travel except at the slicing posi tion, a guard over said substance support and adjacent to said slicing position for preventing access to said knife at said slicing position while said guard is in operative position, said guard being movable to an inoperative position to enable the operator to place the substance to be sliced on said support and to permit access to said knife at said slicing position, a motor for driving said knife, a brake for stopping rotation of said knife, an electrically operated means for controlling the movement of said brake, and interconnecting means between said electrically controlled means, said motor, and said guard so arranged as to render said motor inoperative to drive said knife when said guard is moved to an inoperative position and for substantially simultaneously operating said electrically controlled means for moving said brake into operative position to stop the rotation of said knife.

8. In a slicing machine, the combination with a slicing knife, a casing in which said slicing knife is mounted for bodily movement along a predetermined path, an opening in said casing through which the substance to be sliced is moved, a substance support on one side of said opening, a slice receiver on the opposite side of said opening for receiving slices as they are cut by said knife, a guard movably mounted over said support, a second guard movably mounted over said slice receiver, a motor for driving said knife, a power circuit for actuating said motor, a pair of control elements for rendering said motor circuit operative and inoperative, one of said control elements being connected to one of said guards and the other of said control elements being connected to the other of said guards, and interconnecting means between said control elements and said motor whereby when either of said guards is moved to an inoperative position, its respective control element will render said power circuit inoperative, each of said control elements comprising a switch arranged in series with the other of said control elements in said power circuit, said switches being closed when said guards are in operative position and being open when said guards are in inoperative position.

9. In a slicing machine, the combination with a slicing knife, of a casing for said knife for substantially enclosing the same during its movement along its path of travel but being open at one position to permit the substance to be sliced to be fed into engagement with said knife and having an opening through which slices which are formed are discharged, a support adjacent one side of the opening in said casing, a guard over said support for normally preventing access to said opening whereby the operator of said slicing machine is protected, a power means for driving said knife, a control device for rendering said power means inoperative to drive said knife, a connection between said guard and said control device operable to move said control device to a position such that the same renders said power circuit inoperative whenever said guard is moved to an inoperative position, said support being detachably mounted on said casing, a toggle member, means for urging said toggle member in a direction to move said control device to a position to render said power means inoperative, means carried by said support for holding said toggle inoperative While said support is mounted in operative position with relation to said casing, said last mentioned means being rendered inoperative when said support is

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