US2221481A - Electric control mechanism for bread wrapping machines - Google Patents

Description

T. JENSEN Nov. 12, 1940.

ELECTRIC CONTROL MECHANISM FOR BREAD WRAPPING MACHINES Filed Aug. 19, 1938 2 Sheets-Sheet l FIG. 2

INVENTOR THORMOD JENSEN BY MNEY Nov. 12, 1940. T J NS 2,221,481

ELECTRIC CONTROL MECHANISM FOR BREAD WRAPPING MACHINES Filed Aug. 19, 1958 2 Sheets-Sheet 2 INVENTOR THORMOD JENSEN TTORNEY Patented Nov. 12, 1940 ELECTRIC CONTROL MECHANISM FOR BREAD WRAPPING MACHINES Thormod Jensen, Laurelton, N. Y., assignor to American Machine &Foundry Company, a 001':- I

poration of New Jersey Application August 19, 1938, Serial No. 225,698

5 Claims.

This invention relates to a machine for wrapping articles of the nature of sliced loaves of bread, especially a mechanism in which the loaves are delivered from the slicing machine to a conveyor, running at substantially right angles to the path of delivery, so that the forward movement of the loaves in one sense, say in parallelism with the slicing planes, is translated abruptly into a movement perpendicular to the slices,

that is, the sliced loaves are customarily discharged sidewise from the slicer mechanism and are eventually delivered endwise to thewrapper mechanism.

Machines for such operation of Wrappers in conjunction with slicers are known, and include mechanism for elfecting the reconcilement of the above described differences in path movements,

but the efficiency of these existing machines is not altogether satisfactory, particularly with respect to the mechanism intervening between the slicer discharge and the infeed delivery conveyor to the wrapping machine.

Under such conditions, an object of the present invention is to provide an improved electric con- '25 trol mechanism for bread wrapping machines,

,35 In pursuance of the above general object of the invention, the latter includes the provision .of two general controls for stopping the machine whenever necessary. In the first place, an overload safety control device is provided comprising a series of pins, spring-biased to a coupling position and adapted to be resistingly yieldable lengthwise of their respective axes to uncouple the loaf delivery mechanism from the main drive of the machine, at the same time acting, by vir- 45 toe of said axial movement, to open a normally closed switch included in the electric motor circuit by which the machine is operated, thus deenergizing or incapacitating the circuit and so stopping the machine. 50 The invention includes also provision of a detector switch for the infeed conveyor to the wrapper mechanism which comprises a pivoted plate device spring-mounted adjacent to thein-,

feed conveyor and exteriorly of the wrapping Patent No. 1,689,428.

whenever a loaf is positioned incorrectly on the infeed conveyor it will bear against the, plate, which consequently operates a normally closed switchin the motor energizing circuit, thereby incapacitating the machine by opening said circuit and stopping the motor. I

Other objects and features of the invention will appear as the description of the particular physical embodiment of the invention selected for illustration progresses.

In the accompanying drawings, like characters of reference have been applied to corresponding parts throughout the several views which make up the drawings, in which:

Fig. l is a schematic view in vertical sectional it elevation of part of an electrical control mechanism for a wrapper machine for sliced loaves, in the construction of which the present invention has been embodied; j

Fig. 2 is a partial view in plan of the structure e shown in Fig. 1, taken on the broken line 2 -2; Fig. 3 is a fragmentary detail view on an enlarged scale of the'safety mechanismlshown in Fig. 2; l v

Fig. 4 is a fragmentary, detail view in plan, on a larger scale, of the control unit at theinfeed point of the conveyor {70' the wrapper ,mechanism; y i a v I Fig. 5 is a view of the same in sideelevation with a part shown in clash-dot lines to illustrate a different position; and

Fig. 6 is a fragmentary detail view in side elevation illustrating the safety control lever and associated contact devices. i i

In the now-preferred embodiment of the invention selected for illustration and description, the part designated by the reference character I! is constituted by a portion of the bottom plate of a bread slicing machine (not shown in further detail (along which sliced loaves of bread S are advanced or discharged, by suitable pushers, indicated schematically at I! as taking the form of flights impelled in known manner by conveyor chains (not shown). The loaves are guided in their travel by adjustable side Walls 12 and l3 suspended from bars or other suitable structoral parts of the slicing machine (not shown).

The bottom plate l0 isillustrated as substantially level, but this is not intended to exclude the use of an inclined feed chute for the loaves, 50 such as that disclosed in the aforesaid Farmer Such inclined chutes are used generally where unsliced loaves and similar articles are to be fed to a Wrapping mechanism.

With either a gravity feed, or a positive feed,

as by the pushers II already referred to, or a combination of such feeds, the sliced loaves are preferably discharged past a swinging detector section I4-which will be described hereinafterto a conveyor mechanism disposed substantially at right angles to the bottom plate I0, and which, in the instance illustrated, includes a table or plate 20 (Figs. 1 and 2) having a slot I20 through which extend upwardly spaced flights 3 which engage the sliced loaves S received from the slicing machine and advance them toward a wrapping station, at which, as indicated in Fig. 1, the

loaf S, the plunger 40, lever 42 and wrapper web W, all associated as therein indicated, occupy a position considerably in advance of that occupied by the foremost loaf S in Fig. 2, but in alignment therewith.

Before proceeding to describe the distinctive features which characterize the present invention, it is noted that in a machine of the type herein illustrated by way of example, a plate 4| is provided, adapted to be swung upon a pivot 43 (Fig. 1), down to a position illustrated in 'dotted lines in Fig. 1, opposite to the plunger 40, so

that when the lever 42 is suitably actuated-by suitable means not shown-the plunger 40 will push the loaf S from its full line position in Fig. 1, against a pendant lap L of the wrapper W, suitably disposed, by known or other suitable means, (which need not be described in detail) to effect a partial enfoldment by the wrapper W around three sides of the loaf S.

The member 4| is eventually swung up by a lever 49, operated by a cam (not shown) on the wrapping machine, to a higher level, and each loaf in turn is then advanced by a pusher 68 (one of a series on a conveyor chain not shown) across a bridge piece B to a travelway 69 and into the range of action of the wrapping machine (not shown), where the ends of the wrapper are folded in conventional or other suitable fashion.

The above order of events presupposes the anticipated progress of each loaf duly from the plate III to the plate 20 and its advancement to the wrapping station without displacement or maldisposition of the loaf at any stage of its 'transfer.- To aid such progress, the plate 20 is preferably inclined, as shown in Fig. 1, so that the loaves are gravity-biased into aligned position along a rear wall 32, this wall and the plate 20 being supported by brackets 30 carried by cross-heads I33 mounted on rods 3| fixed in frame parts as in the like structure disclosed in the Farmer Patent, No. 1,689,428, to which reference may be made for a further description of this known structure.

'A shaft 33, journalled in the cross-head I33 serves to support rotatably a double sprocket 34 Which constitutes one of the supports of the endless chains 35 provided with the pushers or fingers already mentioned which pass through the slot I20 of the plate 20 and engage the sliced loaves for advancement to the wrapping station.

So'long as the loaves are properly fed into the.

wall section I4 swings, is supported in spaced end loops I6 of a brace I1 secured to a frame I8 mounted slidingly within a housing I9 extending away from the wall I2 and formed with a slot I90 through which a threaded stud I protrudes to receive a thumb screw I8I by which the frame I8 and its associated parts, including the swinging section I4, may be secured in adjusted position lengthwise of the housing I9.

The frame I8 carries a normally closed electric switch 25 mounted on the brace II, through which extends a push button or trigger 24 by which the switch may be operated to open an electrical control circuit which includes conductors 31 leading to the electric motor by which the machine is driven, and the trigger 24 is adapted to be operated by an actuator arm 23 mounted within the housing I9 and which in turn is engaged by a plunger 22 mounted slidingly within a recess 2| of the swinging section I4, the plunger being spring-pressed against the arm 23 with a tension which is normally insuf ficient to operate the trigger 24 when the parts occupy the position illustrated in Fig. 4.

The full line position is maintained normally by the action of a coil tension spring 28, connected between studs I28 on the section I4 and a wall portion 26 which is pivoted at 21 on the member I4 and is held normally against a stop pin 29 on the member I 4, thus being kept at right angles to the member I4, as shown in Fig. 4, but capable of permitting a knee action at the pivot 21 yieldingly if pressure is exerted against the member I4 by a loaf.

'It will be noted that the outer end I26 of the wall part 26 passes loosely behind an abutment I29 carried by a relatively fixed part of the machine structure, such as the travelway 20 (Fig. 2) and this abutment furnishes a fulcrum for one end of the compound lever or toggle constituted by the members I 4-26.

In operation of this control device,.pressure of a loaf against the member I4 causes the latter to swing on its pivot I5, and carries the plunger 22 (see Fig. 4) around in an are suitable to press the arm 23 against the trigger or push button 24 and open the switch 25, thus stopping the flow of current through the motor control circuit which includes the wires 3'1, and stopping the motor. This will incapacitate the wrapping machine until the obstructing loaf is cleared away, when the spring 28 will reset the member I4, the trigger 24 will be released to permit the switch 25 to restore the normally closed condition of the control circuit through wires 31, and the driving motor of the machine will again be energized to actuate the machine when the usual motor control switch is closed.

The conveyor 35 is intermittently advanced by suitable connections (not shown) with the main drive shaft 41 of the machine, which is preferably driven by an electric motor (not shown), subject to control by an electrical circuit which may desirably include an electric switch device of suitable character, such as that shown in detail at 60 in Fig. 6, which will be described in due course.

The pusher 40 (Fig. 1) already described, is actuated by a lever 42 which, by suitable connections, (not shown) receives motion from a cam 43 mounted on a cam shaft 44 journalled in the supporting structure of the machine.. The shaft 44 also carries a gear 45 in mesh with a pinion 46 wed on the main drive shaft 41. As already noted, the lifting table 4| is fulcrumed on a in suitable timed relation. As a safety means to prevent injury to any of the aforesaid moving parts, or to other parts associated therewith, inthe event of overload of any part actuatedb'y the cam 43,"the latter is connected with its actuating gear by an overload release which includes a series of plungers 52having tapered heads 5| biased lengthwise by coil springs 55 in spaced bosses upon the spokes of the gear 45and thus adapted to enter similarly countersunk recesses 53 in the web 54 of the cam 43.

Figure 3 is an enlarged view of one of these plungers in its operative position. The springs 55 are held in adjusted position against shoulders on the plungers by threaded sleeves 56, which permit axial movement of the plunger stems 52. By screwing the threaded sleeves in or out the springs 55 can be tensioned to obtain the desired gripping pressure of the plungers 52 against the walls of the recesses 53.

This clutch type connection as between gear 45 and cam 54 eliminates the possibility of breaking or damaging any of the working parts of the machine. If an overload or jam occurs, particularly to parts which derive motion from members mounted on shaft 44, such an overload or strain on the shaft will overcome the pressure of springs 55, allowing the plungers to retreat from the recesses 53 and stopping the rotation of the cam.

As a further precaution, the invention provides means whereby the retreat of the plungers lengthwise operates to stop the machine by opening the energizing circuit of the electric driving motor.

The ends 58 of the plungers, as shown in their dotted line position in Fig. 3, project beyond the heads of the threaded sleeves .56, and upon continued rotation of the gear 45, engagement is caused, after less than one-third of a turn, between the head 58 of a plunger and the head 59 of a trip lever 60 which is mounted, as at I66,

pivotally upon a. relatively fixed portion of the frame, as indicated in Fig. 2, adjacent to the annular orbit of the plungers 5| Such an engagement causes the arm or lever 69 to swing about its pivotal axis I60, and in so doing it swings its complemental arm 6| (Fig. 6)

and depresses a pushbutton 62, acting thus to open a normally closed electrical switch 63 included in a control circuit with the electrical driving motor of the machine, the pushbutton moving. its bridge piece 64 from contacts 65, thus stopping the flow of current through the conductors 66, and effecting the de-energization of the motor and the consequent incapacitation of the machine.

When the motor is thus stopped, the machine will remain inoperative until the cause of the disengagement shall have been corrected and the shaft 41 turned manually until the plungers 5| again enter the recesses 53 as shown in Fig. 3 whereupon the control circuit will be rehabilitated and the machine can be set in motion after the usual starting switch shall have been closed by the operator.

The arm 60 is held in its normal position by a spring 61 in the switch 63.

As already noted briefly, each loaf in being 'transferredrin a crosswise direction onto the table4| encounters the downhanging free end L of the wrapper webW, (Fig; 1) which is thereby folded about a portion of the loaf as the latter arrives 0n the table 4|. The downfolding of the ends of the Wrapper is performed while the table 4| carries the loaf to its upper'position from which the pusher 68, depending from endless chains (not shown),transfers"the loaf onto a runway 69. 1 a l I Upon entering the runwaythe tail end of the wrapper, which has been severed from the web by a cam-actuated knifelfl, in known fashion,

is folded under the loaf While carried along the runway 69, the remaining end and bottom.

flaps of the wrapper are folded against the loaf and the wrapper is sealed by suitable means incorporated in the runway, but not illustrated; as such mechanism i well-known to those skilled in the art.

What is claimed is:

1. In an article feed for a wrapping machine of the class described having an articleway,

mechanism to advance sliced loaves in said articleway, and a prime mover to actuate said mechanism, an electrical control circuit provided with means to incapacitate said prime mover,

and an electrical switch included in said control circuit, said switch including a switch operator device responsive to an overload upon said mechanism initiated by the movement of an .un-

wrapped sliced loaf in misplaced position in the articleway, said operator device being adapted upon occurrence of such an overload to operate the switch and incapacitate said prime mover.

2. An article feed having the features claimed in claim 1, in which said operator device is constructed and arranged to hold the switch in said position to incapacitatethe prime mover, with the machine stopped, until removal of the obstructed condition in the articleway, and means prime mover, and an electrical switch included I in said control circuit, said switch including a switch operator device forming a yielding section 1 of one of said guide walls and adapted to be actuated automatically exclusively by a defective or misplaced article, such switch operation constituting the sole function of said yielding section.

4. An article feed for a wrapping machine of the class described, having the features claimed in claim 2, wherein provision is made of electrie cal switches each included in such a control circuit, said switches each having a switch operator device, one of said operator devices being responsive exclusively to an overload condition of the mechanism and another operator being responsive exclusively to the presence of a misplaced or defective article in said articleway, said overload device being arranged to permit cyclical rehabilitation by the prime mover upon removal of the overload condition, while said mechanism responsive to misplacement remains unaffected,

and means acting to reset said last-named op- .erator device and its switch automatically to Jpermit oper'atio-npf the machine immediately upon removal of the obstructed condition without manual intervention other than that involved in the normalcontrol of the machine.

5. In an article feed of the class described hav ing anarticleway, mechanism to advance articles in said articleway, a feedway adapted to receive a supply-of said articles and mechanism to feed ll) said articles from the feedway to the articleway in a direction substantially at right angles to the path of said articles in the articleway, an electrical control circuit provided with means to incapacitate said mechanism, a control switch included in said circuit, and a switch operator device actuated automatically exclusively by a defective or misplaced article passing fromsaid feedway to said articleway; said switch operator said control switch comprising a normally closed electric switch mounted within said housing and provided with a control button or trigger by which said control switch may be operated to open said control circuit, an actuator arm disposed within said housing, and a plunger mounted in said swinging wall section, whereby swinging movement of said section operates said plunger to move said actuator arm, actuate said control button or trigger and open said control cir- [-15 cuit.

THORMOD JENSEN.

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