US3077910A - Multiple-action loaf slicing machine - Google Patents

Description

Feb. 19, 1963 w. w. HARTMAN 3,077,910

MULTIPLE-ACTION LOAF SLICING MACHINE Filed July 12. 1960 4 Sheets-Sheet 1 W/u mm .WHHITMFM/ Feb. 19, 1963 w. w. HARTMAN MULTIPLE-ACTION LOAF SLICING MACHINE 4 Sheets-Sheet 2 Filed July 12. 1960 INVENTOR. 5421/4 14 WAQeTMflA/ Feb. 19, 1963 w. w. HARTMAN MULTIPLE-ACTION LOAF SLICING MACHINE 4 Sheets-Sheet 3 Filed July 12. 1960 3,077,910 MULTWLE-ACTION LOAF SLICING MACHlNE William W. Hartman, 418 S. June St., Los Angeles, Calif. Filed July 12, 1960, Ser. No. 42,288 7 Claims. (Cl. 146-88) This invention deals generally with slicing machines of the type adapted to slice loaves of bread and the like and, more particularly, with a unique multiple-action, loaf slicing machine which substantially increases production and saves valuable floor space in todays crowded commercial bakeries.

Reference is made herein to my prior U.S. Patent No. 2,759,510 entitled Feed Mechanism for Bread Slicing Machine issued August 2.1, 1956.

In the loaf slicing and wrapping art as presently practiced, each loaf slicing machine consist sof a series of horizontally spaced knives which are moved longitudinally either in a vertical direction or in a direction inclined slightly from the vertical and a single feed mechanism for feeding the loaves to be sliced to and through a single slicing zone of the knives. Each slicing machine serves only a single wrapping machine.

The output of a slicing machine of this type can be increased only by increasing the rate of travel of the loaves through the machine. This method of increasing output is unsatisfactory since it involves much more rapid operation of the machine components, which complicates the initial machine design and subsequent machine maintenance, and, perhaps more important, the increased operating speeds result in damage to the loaves or unsatisfactory slicing thereof.

A general object of this invention is to provide a new and improved loaf slicing machine in which one slicing mechanism is made to serve a plurality of infeed mechanisms and a plurality of wrappers, thereby doubling or tripling the total output of the slicing mechanism without appreciably increasing its overall cost.

A more specific object of the invention is to provide a multiple-action, loaf slicing machine of the character described which is characterized by a plurality of parallel loaf feeding mechanisms arranged along a common set of slicing knives so that the loaves handled by the different feed mechanisms are sliced in different slicing zones of the same slicing knives.

Yet another object of the invention is to provide a multiple-action, loaf slicing machine of the character described in which the several loaf feed mechanisms are driven in synchronism from a common drive means in such a way that a loaf is sliced in only one slicing zone at a time so as to avoid undue loading and flexing of the slicing knives.

A further object of the invention is to provide a mult iple-action, loaf slicing machine of the character described embodying a shiftable conveyor means for selectively transferring loaves to be sliced from a single infeed conveyor belt to the different loaf feeding mechanisms of the machine.

Yet a further object of the invention is to provide a multiple-action, loaf slicing machine of the character described which is used in conjunction with a multiple-action, loaf wrapping machine consisting of separate Wrapping mechanisms, each of which receives and wraps the sliced loaves from a respective slicing zone of the slicing machine.

Other objects, advantages and features of the invention will become readily apparent as the description proceeds.

Briefly, the objects of the invention are attained in the illustrative embodiment thereof by providing a loaf slicing machine equipped with a pair of parallel loaf feeding mechanisms mounted :one over the other on a common fname and along a common set of slicing knives in such Patented Feb. 19, 1963 a way that theupper feed mechanism moves its respective loaves against an upper portion or slicing zone of the knives and the lower feed mechanism moves its loaves. against a lower portion or slicing zone of the knives. The

loaves sliced in these upper and lower zones are conveyed to two separate wrapping mechanisms arranged one over the other. Preferably, the two loaf feeding mechanisms of the slicing machine and the Wrapping mechanisms are driven in synchronism from a common drive means in such a way that loaves are sliced alternately in the two slicing zones. In this way, undue loading and flexing of the slicing knives is avoided.

The illustrative two level construction of the present loaf slicing machine should be regarded as being merely illustrative and not limiting in nature. That is to say, the slicing machine of this invention may have as many as three or even more slicing levels, depending upon the desired total output. With three or more slicing levels, loaves are preferably sliced successively or alternately in the several slicing zones to avoid undue loading and flexing of the slicing knives.

The highly import-ant advance in the art achieved by this invention, namely, that one slicing mechanism is made to serve a plurality of loaf feeding mechanisms and a plurality of wrappers, thereby doubling or tripling the total output of the mechanism with only a. slight increase in the cost of the overall slicing machine, and at the same time minimizing floor space requirements, results, primarily, from the use of one particular form of existing slicing mechanism which is uniquely adapted to the pres-= ent multiple slicing action. This well-known type of slicing mechanism consists of a multiplicity of parallel blades mounted side by side with their cutting edges substantially in the same transverse plane and with the adjacent blades moving in opposite directions.

It will become apparent as the description proceeds that the invention does not consist merely in placing one slicer on top of or beside another slicer and one wrapper on top of or beside another wrapper and then interbuilding them into one frame forthe purpose of doubling the output. This type of construction would result in an extremely complex and commercially impractical slicing.

machine.

The illustrative embodiment ofthe invention will now be described in detail by reference to the attached drawings, in which:

FIG. 1 is a view, in side elevation, of a double-acting loaf slicing machine and wrapping machine according to the invention;

FIG. 1a is an enlargement'of the area encircled by arrow 1a in FIG. 1;

FIG. 2 is an enlarged view, in side elevation, of the internal mechanism of the slicing machine in FIG. -1;

FIG. 3 is a view looking in the direction of the arrows on line 3-3 of FIG. 2;

FIG. 4 is a view looking in the direction of thearrows on line 4-4 in FIG. 2;

FIG. 5 diagrammatically illustrates, on a further enlarged scale, the alternate slicing action of the slicing machine;

FIG. 6 is a timing diagram of the machine;

FIG. 7 is a somewhat exaggerated perspective view of a single band blade showing the manner of mounting and twisting the blades with respect to the drums; and

FIG. 8 is a view of the drums and-multiplicity of blades thereon taken as indicated by the arrows 88 on FIG. 7.

aforementioned U.S. Patent No. 2,759,510. Accordingly,

the parts of the present machine which are similar to those of the prior machine will be only briefly discussed herein. If additional description of these parts is desired, reference should be had to the patent.

The slicing machine 20 comprises a main frame structure 22 including an upper inclined housing extension 24 enclosing the slicing mechanism 26. As preliminarily mentioned, one particular well-known type of slicing mechanism is especially well suited for use in the machine, namely, one consisting of a plurality of parallel blades or knives mounted side by side with their cutting edges substantially in the same transverse plane and with the adiacent knives moving in opposite directions. Slicing mechanisms of this general character are illustrated in US. Patents Nos 2,143,242, 2,173,038 and 2,424,659.

For simplicity, the slicing mechanism 26 illustrated in the present drawings is of the type disclosed in U.S. Patent No. 2,424,659 and includes a plurality of endless cutting bands or blades 28 which are twisted into the usual figureeight arrangement and trained about supporting and guiding rolls or drums 3% past guide means 31. The latter may consist of pairs of guides 31 so that in the zone Z1, between the pair of lower guides 31, and in the zone Z2, between the pair of upper guides 31, the bands or blades 28 are parallel and have their cutting edges substantially in a common transverse plane Pli which is parallel to the guiding rolls 3t) and is inclined slightly from the vertical. Since these blades are located one behind the other in the drawings, only the forward blade 28 is visible. For more detailed drawings and description of one form of the parts described in this paragraph, the reader is referred to my previously mentioned United States Patent No. 2,424,659, dated July 29, 1947, particularly FIGS. 1, 2 and 3 of the drawings thereof and also the written description thereof. The multiplicity or group of endless cutting bands 28 of this present application are shown as the bands or strands 14 and 15 of said patent; the two sets or pairs of spaced guiding rolls 3% of this application are indicated by parts 16 and 12, both together comprising one set or pair of such rolls, and by parts 11 and 13 together comprising the other set or pair of such rolls, in said patent; and the said guide means 31 of this application is indicated by one of the two guides or parts 22 in said patent. All these parts are shown in either FIGS. 1, 2 or of this application, but they are shown larger and more clearly in said patent, as just referred to.

While the layout of a slicing machine embracing my invention, can be left to the wishes of the designer, I wish to point out that in the preferred form of my slicing machine I prefer the arrangement of the guide rolls 3t), and of the cutting bands 23, to be more or less as shown in FIG. 1 of this present specification, wherein the cutting bands occupy a more or less upright, though inclined, position or direction as shown in said FIG. 1. This is brought about by having one set or pair of guide rolls 39 located higher than the other set or pair of such guide rolls 30, and this general arrangement of the guide rolls and cutting bands obviously permits the loaf feeding mechanism 34 and 32, FIGS. 1 and 2 hereof, to be located one higher than the other along the cutting bands as shown in said figures; and of course this permits the corresponding and hereinafter described wrapper parts 52 and 50 of FIGURE 1, to be similarly located at successively higher elevations with respect to each other. All this in turn is of considerable importance in the large modern bakeries, in that it permits the total slicing and wrapping apparatus to be very compact and concentrated in the sense that it utilizes the available floor space in such bakeries very efiiciently in comparison with any other slicing apparatus now available. That is, with my arrangement as just described, substantially more loaves can be sliced and wrapped for each square foot of floor spaced allotted to this purpose, than with any other arrangement of slicers or wrappers now known, and this is of prime importance to the larger bakeries now using this kind of equipment because in many of them, and for various reasons, the operating conditions are today quite congested in the general vicinity of the slicers and wrap pers, and floor space is at a premium. Therefore, in concluding this part of the description, I wish to point out that my invention serves the double purpose of multiplying the production of the slicer at a disproportionately small increase in the cost of the slicer, and at the same time of producing such compactness in the slicer and the wrapper as to substantially relieve the congestion usually found in the bakeries around the slicers and wrappers. The advantages of achieving at one stroke, this double purpose or benefit, need not be further emphasized.

The primary improvement feature of the present slicing machine resides in the provision of two separate loaf feeding mechanisms in the machine, namely, a lower feed mechanism 32 and an upper feed mechanism 34- which are mounted one over the other on the frame 22 and having delivery portions to said cutting bands 28 between said guide means. As will presently be more fully described, these feed mechanisms operate to alternately convey loaves to be sliced through the two vertically spaced zones Z1 and Z2, hereinafter referred to as slicing zones, of the same slicing mechanism 26.

The loaves to be sliced are conveyed to the slicing machine 20 on a single horizontal conveyor belt 36. Located between this conveyor belt and the slicing machine is a transfer conveyor 38 which receives loaves from the conveyor 36. The end of the transfer conveyor, adjacent the main conveyor, is hinged on an axis 40 for vertical swinging of the other end of the transfer conveyor 38 between its solid line position of FIG. 1, wherein it delivers loaves to the upper feed mechanism 34 of the slicing machine, and its phantom line lower position, wherein it delivers loaves to the lower feed mechanism 32 of the machine.

The transfer conveyor is moved between its upper and lower positions in any suitable way, such as by hand, or by means of a cam 42 which vertically moves a cam follower rod 44, pivotally connected at its upper end to the free end of the transfer conveyor 38, and is driven in synchronism with the slicing machine 20 through a chain drive 46 and a reduction gear unit 48. Cam 42 is, therefore, slowly rotated in synchronism with operation of the slicing machine 20 and has the configuration illustrated which erTects retention of the transfer conveyor 38 in its upper position for one-half of a cam revolution and in its lower position for the other half of the cam revolution.

The main conveyor belt 36 is driven at approximately twice the average speed at which loaves are conveyed through each of the upper and lower levels of the machine by the upper and lower feed mechanisms 34 and 32 so as to maintain a constant supply of leaves to the machine sufiicient to keep both the upper and lower levels of the machine filled. The transfer conveyor 38 is driven by a motor 49, at a somewhat greater speed than conveyor 36, and is energized through a switch 49a, operated by a cam 49!; on the side of cam 42, which opens the switch to stop the transfer conveyor 38 when the latter is being shifted up or down and restart it when it reaches its upper or lower position.

Located behind the slicing machine 20, that is, to the right of the machine as it is viewed in FIG. 1, are two wrapping mechanisms 5t) and 52 which are mounted one over the other, as shown. As will be shortly more fully described, the lower wrapping mechanism 50 receives and wraps the sliced loaves from the lower level of the slicing machine. The upper wrapping mechanism 52 receives and wraps the sliced loaves from the upper level of the slicing machine. These wrapping mechanisms may be of any conventional type and are operated in synchronism from a common drive means 54. This drive means also drives a power take-oft shaft 56 from which the slicing machine 2% is operated in synchronism with the wrapping mechanisms, as will presently be described.

The lower loaf feeding mechanism 32 is driven by a drive mechanism 58 which also drives the upper feed mechanism 34. The mechanism of the lower level of the machine, comprising the lower feed mechanism 32 and thedrive mechanism 58,-is identical in many respects to'the mechanism of my prior slicing machine. For this reason, as already noted, the following description of these parts will be abbreviated, it being understood that if additional details of the same are required, reference may be had to my patent.

The lower loaf feeding mechanism 32 comprises a first intermittently operated infeed conveyor belt 66, a second fast, continuously traveling endless conveyor 62, preferably constituted of' a plurality of spaced sprocket chains 64, a third, continuously operating pusher conveyor unit 66, a fourth, continuously operating outfeed conveyor belt 68, step fingers 70 which are periodically retracted to permitmovement of the loaves to be sliced from the fast conveyor 62 to the conveyor unit 66, and a loaf holddown or stabilizer 71 These several components of the lower loaf feeding mechanism are operated in synchronism, by the drive mechanism 58,- in the manner to be hereinafter briefly discussed, to feed the lower row of loaves a to be sliced to and through the lower slicing zone Z1 of the slicing machine.

Drive mechanism 58 includes a main, continuously and uniformly rotating drive shaft 72, which is driven from the power take-off shaft 56 of the main drive means 54, through sprocket chains 74 and 76, and a second driven shaft 78, which is driven from shaft 72 through a sprocket chain 80. The second, fast conveyor 62 and the fourth, outfeed conveyor belt 68 are driven directly from shaft 78 through sprocket chains 82 and 84, respectively. Mounted on the forward end of shaft 78 is a first crank arm 86, to the outer end of which is pivotally connected the connecting rod or arm 88 that actuates the ratchet mechanism 90 for intermittently driving the infeed conveyor belt 60. The conveyor unit 66 is driven, via a sprocket chain M, from shaft 78 of the drive mechanism.

The upper loaf feed mechanism 34 is carried on an upper table 92 mounted over the lower table 94 which is apertured to receive the lower infeed conveyor belt 69. This upper feed mechanism is identical to the lower feed means and comprises a first intermittently operated infeed conveyor belt 96 located within an aperture in the upper table 92, a second fast, continuously traveling endless conveyor 93 consisting of a plurality of spaced sprocket chains 9?, a third, continuously operating pusher conveyor unit 100, a fourth, continuously traveling outfeed conveyor belt Hi2, stop fingers 164 which are periodically retracted to permit movement of loaves to be sliced from the fast conveyor 98 to the-conveyor unit 1%, and a loaf holddown or stabilizer 1G6.

Theinfeed conveyorbelt 96 is intermittently operated by a ratchet mechanism 1% identical in construction and operation to the lower ratchet mechanism 90 which operates the lower infeed conveyor belt 63. This upper ratchet mechanism is located at the opposite side of the machine frame 22 from the lower ratchet mechanism, i.e., the read side of the frame as the machine is viewed in FIG. 2. As shown best in FIG. 4, the shaft 110 of the upper mechanism is journaled in a bearing 111 located at the underside of the upper table 92 and carried on a vertical supporting member 112 for the upper table.

The upper ratchet mechanism is actuated by a connecting rod or arm 114, the lower end of which is pivoted to the outer end of a second crank arm 116 fixed on the rear end of shaft 73 in the lower drive mechanism 58, as the latter is viewed in FIG. 2.

Crank arms 86 and 116 are displaced 180, as may be best observed in PEG. 2. As a result, during rotation of shaft 78, in the drive mechanism 53, through one-half of a revolution, the connecting rod 11 is moved downwardly to actuate the upper ratchet mechanism 1193 and thereby advance the upper infeed conveyor belt 96 a short distance while the lower connecting rod 88' is moved upwardly to reset the lower ratchet mechanism 99 and the lower infeed conveyor belt 60 remains stationary. During the next half revolution of shaft 73, the upper connecting rod 114 is moved upwardly to reset the upper ratchet mechanism while the lower connecting rod 88' is pulled downwardly to actuate the lower ratchet mechanism 9d and thereby advance the lower infeed conveyor belt 6t) a short distance. Thus, the upper and lower infeed conveyor belts are intermittently operated in alternate fashion during operation of the machine.

The second fast conveyor 98, conveyor unit 101 and the outfeed conveyor belt 192 of the upper feed mechanism 34 are driven from the drive mechanism 58, as follows: The forward end of the sprocket shaft 118 of the lower fast conveyor 62, which shaft is driven by the sprocket chain 82, and the sprocket shaft 121 of the upper fast conveyor 1% are extended forwardly of the machine, as the latter is viewed in FIG, 2, and mount sprockets 122 and 124, respectively, at their forward outboard ends. Trained about these sprockets is a sprocket chain 126 whereby the upper fast conveyor is driven from the driven shaft 118 of the lower fast conveyor.

Similarly, the sprocket shaft 128 of the lower conveyor unit, which shaft is driven by the sprocket chain 91, and the sprocket shaft 130 of the upper conveyor unit 100 areextended forwardly, as the machine is viewed in FIG. 2, and mount at their forward outboard ends sprockets 132 and 134 around which is trained a sprocket chain 136 so that the upper conveyor unit 104) is driven from the driven shaft 128 of the lower conveyor unit.

Finally, the driven shaft 137 of the lower outfeed conveyor 68, which shaft is driven by the sprocket chain 84, and the shaft 138 of the upper outfeed conveyor 192 are extended forwardly and mount sprockets 139 and 141) about which is trained a sprocket chain .142 that drives the upper outfeed conveyor 102 from the driven shaft 137 of the lower outfeed conveyor.

Thus, during operation of the machine, the three lower conveyors 62, 66 and 63 and the three upper conveyors 98, 100 and 102 are continuously driven in synchronism. As shown best in FIG. 5, the loaf pushing means or pushers 144 of the lower conveyor unit 66 are displaced from the loaf pushing means or pushers 146 of the upper conveyor unit 100, for reasons to be presently seen. For the purpose of greater clarity in the foregoing description, 1 wish to point out that the loaf pushers 144 in the lower loaf feeding mechanism, and the corresponding pushers 146 in the upper or higher loaf feeding mechanism, and their continuously operating endless conveyors hereinbefore mentioned and shown in FIGS. 2 and 5 of the drawings herein, are the pushers 111 and their endless chain conveyor 112 shown in FIG. 3 of my aforesaid United States Patent Number 2,759,510, dated August 21, 1956, and the latter parts are all thoroughly described in the written specification of said patent to which attention has been previously directed in this present specification.

The lower stop '70 and holddown '71 are operated by a pair of cams 148 and 150 fixed on the shaft 78, as described in my prior patent. The upper stop 1114 and the upper holddown 106 are operated by an additional cam 152 fixed to the forward end of the shaft 78, just behind the crank arm 86, as the machine is viewed, in FIG. 2. This cam is identical in shape to but is displaced 180 from the cams 148 and 150.

Pivoted to an upstanding bracket 154 on the frame of the machine is a cam follower arm 158 mounting a cam follower roll 160 which rides on the periphery of earn 152. A vertical connecting arm 162 is pivotally connected at its lower end to the free end of the cam 7 follower arm 15% and at its upper end to an arm 164 which is rigid on a shaft 166.

As shown best in FIG. 4, shaft 166 is rotatably supported in bearing blocks 16% fixed to the underside of the upper table 92. Firmly fixed at one end to this shaft are a pair of spaced, parallel arms 170, the upper ends of which, as the machine is viewed in FIG. 4, underlie the upper fast conveyor 98. Fixed to and bridging these ends of the arms 170 is a crosspiece 172 to which the lower ends of the upper stop fingers 194- are rigidly fixed.

Also rigidly secured at one end to the shaft 166 is an arm 174, to the other end of which is pivoted the lower end of a link 176. The upper end of this link is connected to the upper holddown 166.

When the cam 152 rotates, therefore, the upper stop 104 and the holddown 106 are raised and lowered in exactly the same way as the lower stop '70 and holddown 71. Since cams 143 and 150 are 180 displaced from cam 152, however, the upper stop and holddown are raised and lowered 180 out of phase with the lower stop and holddown.

In operation of the present double-action loaf slicing machine, the transfer conveyor 38 is alternately shifted between its upper and lower positions, by operation of its actuating mechanism 42-48, to continuously feed loaves to be sliced to the upper and lower levels of the machine. Thus, the transfer conveyor, when in its upper position rapidly feeds a number of loaves to the upper level of the machine suificient to fill its infeed conveyor belt 96, the loaves sliding along the belt to the last loaf then on the belt. The cam 4% then opens switch 490 to stop the transfer conveyor, whereupon the latter is lowered, by cam 42, to its lower position and restarted by reclosing of switch 49a by cam 4%. While the transfer conveyor is thus inoperative, it continues to receive loaves from the main conveyor 36 which close the gap resulting from rapid feeding of the loaves to the upper level. When restarted in its lower position, the transfer conveyor delivers a number of loaves to the lower level of the machine sufiicient to fill its infeed conveyor belt 60, whereupon the conveyor is shifted to its upper position and the cycle is repeated. As mentioned earlier, the transfer conveyor may, if desired, be shifted by hand, rather than automatically. Alternatively, of course, the two levels of the present machine may be loaded by hand.

The operating cycle of each level of the present machine is substantially identical to that described in my prior patent. The operation of the machine as a Whole will now be described by reference to the timing diagram of FIG. 6 in which position the inner full line circles are for the lower level of the machine and the outer full line circles are for the upper level of the machine. Position I of the diagram corresponds to the position of the machine illu-strated in FIG. 2. At this time, the lower level of the machine is about to complete its current cycle of operation and start the next cycle, which occurs at position I Thus, at I, on the timing diagram, the lower stop fingers 70 and holddown 71 are elevated by their cams 148 and 150, and the lower infeed conveyor 60 is being driven through the last few degrees of its travel, by its crank 86 and ratchet feed mechanism 90, to advance the string of loaves d, e and f on the conveyor to a position where the first load d engages the elevated stop fingers 7 t3. Loaf c is on the lower pusher conveyor unit 66, about to be engaged by a pusher 144 of the unit, and loaf b is being advanced, by the previous pusher 144, against the knives 28 in the lower slicing zone Z1 after having pushed the first loaf a ahead of it through the knives onto the lower outfeed conveyor 68. Sliced loaf a is carried to and wrapped in the lower wrapper St). A few degrees later in the cycle, at position 1 the lower infeed conveyor 6% comes to a stop, and the pusher 144 engaging loaf b reaches the d o its forward travel and drops out of engagement with the loaf leaving the latter in a partially sliced condition part way through the knives 2-8.

The upper level of the machine is 180 out of phase with the lower level of the machine. Accordingly, at position l of the timing diagram, loaf b is being advanced by a pusher 146 of the upper conveyor unit 100, toward loaf a which is stationary and in a partially sliced condition part way through the knives 28 in the upper slicing zone Z2 of the machine. Loaf c has just been released by lowering of the upper stop fingers 104 and holddown res and is being kicked onto the conveyor unit 160 behind the pusher currently engaging loaf b, by the high speed chains of the upper fast conveyor 98, as shown in FIG. 2.. I

A few degrees later, at position I of the timing diagram, when slicing ends in the lower slicing zone Z1 of the machine, advancing loaf b in the upper level engages the partially sliced loaf a to commence slicing in the upper zone.

Sixty degrees later in the cycle of the machine, at position 1 the lower stop fingers 70 and holddown 71 have been lowered by their cams 148 and 150 to release loaf d, presently on the lower fast conveyor 62,, which-is kicked onto the lower conveyor unit behind the pusher 144 then advancing loaf 0 toward the partially sliced loaf b, which is part way through the knives 28. At position I, on the timing diagram, 180 away from position I loaf c engages loaf b to commence slicing in the lower slicing zone Z1 of the machine, as shown in FIG. 5.

in the upper level of the machine, during the half cycle between positions 1 and I, of the timing diagram, loaf b' pushes loaf of on through the knives 28 to complete slicing of the latter loaf, whereupon loaf b is pushed against the knives. The pusher of the upper conveyor unit lilil reaches the forward limit of its travel at position 1 of the diagrarnand then drops out of engagement with the loaf b, leaving the latter part way through the knives, to terminate slicing in the upper zone Z2, as shown in FIG. 5.

At position 1,; of the half cycle under discussion, which is after dwell of the upper stop fingers 104 and holddown 166 in their lowered position, they are again elevated by earn 152. Shortly thereafter, at position 1 of the diagram, the crank 116 starts its downward stroke to actuate the upper ratchet mechanism 108 and advance the upper infeed conveyor 96, during the interval between positions I and I of the diagram, which brings loaf :1 against the upper, elevated stop fingers 104. The upper infeed conveyor stops at position 1 on the timing diagram to complete a cycle of operation of the upper level of the machine.

It will be recalled that at position I, of the diagram, slicing is terminated in the upper slicing zone Z2, while in the lower level of the machine, advancing loaf cengages the partially sliced loaf b to commence slicing in the lower slicing zone Z1. Slicing contines until loaf b has been pushed on through the knives 28, to complete slicing of the latter loaf, and the pusher 144- reaches the forward limit of its travel and drops out of engagement with loaf c after having pushed the latter through the knives. This occurs at position 1 of the diagram.

During the latter half of the cycle of the machine, between positions I, and I and after 150 dwell of the lower stop fingers 70 and holddown 71 in their lowered position, they are elevated at position 1,, of the timing diagram. Shortly thereafter, at position L, of the diagram, crank 86 commences its downward stroke to actuate the lower ratchet feed mechanism 9% and, again, advance the lower infeed conveyor 60. This continues to position I; on the diagram, during which loaf e is advanced to the elevated stop fingers 70, whereupon the lower infeed conveyor comes to a stop to complete another cycle of the lower level of the machine.

In the upper level of the machine, 60 after position I, of the diagram, at position L7, the stop fingers 104 and holddown 106 have been lowered by their cam 152 to release load d which is then kicked onto the upper conveyor unit 100, by the fast moving chains of the unit, behind the pusher 146 which is currently advancing loaf c toward the partially sliced loaf b'. At position I; of the timing diagram, the advancing loaf c' engages loaf b' to commence slicing in the upper slicing zone Z2.

This, then, completes one operating cycle of the machine during which loaf a was completely sliced, and loaf b was partially sliced in the upper slicing zone Z2 and loaf d was released for movement onto the lower conveyor unit 66 between position I and L; on the timing diagram, and loaf b was completely sliced and loaf c was partially sliced in the lower slicing zone Z1, and loaf c was released for movement onto the upper conveyor unit 100 during the interval between positions 1 and I on the diagram.

During the next cycle of the machine, loaf b is completely sliced and loaf c is partially sliced in the upper zone of the machine and loaf e is released by the lower stop fingers 70 for movement to the lower conveyor unit 66 during the interval between positions I and 1 of the timing diagram. In the last half of the cycle, between positions I, and I of the diagram, loaf c is completely sliced and loaf d is partially sliced in the lower slicing zone Z1 while, in the upper level of the machine, loaf e is released by the upper stop fingers 104 for movement onto the upper conveyor unit 100.

From the foregoing description, it is evident that in the particular form of feed mechanism shown, loaves are sliced in only one slicing zone of the machine at any one time. Excessive deflection and loading of the knives 28 is thereby avoided.

It is also obvious that because of the two level construction of the present machine, its output is twice that of a conventional single action machine while the speed of the parts and the rate of travel of the loaves through the machine remain the same as in the single action machine. As preliminarily mentioned, the machine may have more than two slicing levels in which case, of course, the output of the machine is further increased. In this case, the several levels are preferably synchronously operated in such a way that loaves are sliced successively in the several slicing zones of the common set of slicing knives in order to avoid undue loading and flexing of the latter.

It is clear, therefore, that the loaf slicing machine hereinbefore described and illustrated is fully capable of attaining the several objects and advantages preliminarily set forth.

While a presently preferred embodiment of the machine is disclosed for illustrative purposes, numerous modifications in the design, arrangement of parts and instrumentalities of the invention are obvious within the spirit and scope of the following claims.

What is claimed is:

1. A machine for slicing loaves of bread and the like, comprising a group of endless cutting bands having two sets of spaced guiding rolls, at least two spaced guiding means for said bands between said two sets of rolls, the bands between said guiding means being substantially parallel, and at least two loaf feeding mechanisms adjacent said cutting bands and having delivery portions between said guiding means.

2. The subject matter of claim 1, wherein each of the two sets of guiding rolls comprises a pair of guiding rolls.

3. The subject matter of claim 1, wherein the cutting bands between said guiding means are side by side and have their cutting edges substantially in a common plane extending parallel to said guiding rolls, and wherein adjacent strands of said bands run in opposite directions.

4. The subject matter of claim 3, wherein one of said sets of guiding rolls is located higher than the other of said sets of guiding rolls, and wherein said loaf feeding mechanisms are located one higher than the other along said cutting bands.

5. The subject matter of claim 4, wherein the two spaced guiding means for said bands comprise a pair of guides for each of said loaf feeding mechanisms.

6. The subject matter of claim 4, including in said loaf feeding mechanisms positive loaf pushing means timed to alternately push the loaves against said cutting bands.

7. The subject matter of claim 4, including in each of said loaf feeding mechanisms endless conveyor means immediately ahead of said cutting bands, said endless conveyor means having loaf pushers spaced therearound for successively pushing loaves against said cutting bands, and the loaf pushers on one of said loaf feeding mechanisms being displaced with respect to the loaf pushers on another of said loaf feeding mechanisms to push the loaves against said cutting bands alternately between the loaf feeding mechanisms.

References Cited in the file of this patent UNITED STATES PATENTS 2,143,242 Hartman Jan. 10, 1939 2,569,545 Tatosian Oct. 27, 1951 2,739,694 Hatch et al. Mar. 27, 1956 2,759,510 Hartman Aug. 21, 1956 2,827,150 Eaton et a1 Mar. 18, 1958

Claims (1)

1. A MACHINE FOR SLICING LOAVES OF BREAD AND THE LIKE, COMPRISING A GROUP OF ENDLESS CUTTING BANDS HAVING TWO SETS OF SPACED GUIDING ROLLS, AT LEAST TWO SPACED GUIDING MEANS FOR SAID BANDS BETWEEN SAID TWO SETS OF ROLLS, THE BANDS BETWEEN SAID GUIDING MEANS BEING SUBSTANTIALLY PARALLEL, AND AT LEAST TWO LOAF FEEDING MECHANISMS ADJACENT SAID CUTTING BANDS AND HAVING DELIVERY PORTIONS BETWEEN SAID GUIDING MEANS.

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