US2424659A - Band blade slicing machine - Google Patents

Description

July 29, 1947. w. w. HARTMAN BAND BLADE SLICING MACHINE Filed Feb 11, 1946' 2 Sheets-Sheet.- 1

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Jul 29, 1947. w W, HAR MAN 2,424,659

BAND BLADE SLICING MACHINE Fild Feb. 11, 1946 2 Sheets-Sheet 2 W/zA/AM 1444.4 727? fiZPT/VAN,

INVENTOR.

Patented July 29, 1947 UNITED STATES PATENT OFFICE BAND BLADE SLICING MACHINE William Walter Hartman, Los Angeles, Calif.

Application February 11, 1946, Serial No. 646,793

2 Claims. 1

This invention relates generally to machines for slicing loaves of bread, or other articles, and more articularly to the endless bandblade type of slicer. The present invention may be regarded as dealing with improvements in the type of bread slicing machines disclosed in my prior United States Patents Nos. 2,143,242 and 2,179,- 659.

With the simple and well known figure 8 type of multiple band blade slicing machine, the endless b-and blades are each twisted through 180 into figure 8 form, and the two loops so formed in each blade are mounted on two parallel upper and lower blade supporting drums. This brings the mid-points of all the blade courses between said drums into parallel planes which are normal, i. e., at right angles, to the blade supporting drums as well as to the loaves coming on to be sliced. However, without further provisions, the blade courses are only in such a condition of normalcy at their exact mid-points. In order to provide n extent of normal blade course equal to the height of a loaf, it has been common to provide such a machine with two sets of bladetwisting guide means having close-fitting narrow blade guide slots parallel to one another and normal to the drums. Between these two sets of guide means the blade courses are normal. These two sets of blade guide'means preferably engage the blade course at equal distances from the mid-points thereof and at a proper spacing to permit a loaf to be passed therebetween. Such a machine has one serious disadvantage, which is that the two sets of blade courses cross each other at such a large angle that the oncoming loaves are somewhat pinched or crushed between the two sets of blade courses.

The problem mentioned in the preceding paragraph has long been recognized, and solutions therefor have been presented in my two aforesaid patents. In both cases, speaking broadly, the solution was to employ blade deflecting guide drums located near the two blade supporting drums in such association therewith as to engage and deflect the blade courses in a manner to substantiall reduce or practically eliminate their crossing angle, thus bringing them toward if not precisely into a common transverse cutting plane. In my Patent No. 2,143,242, I disclosed an arrangement utilizing two such blade deflecting drums, placed adjacent and just inside the two blade supporting drums, both being positioned on the same side of and close to a plane tangent to corresponding sides of the supporting drums, and in such arrangement that one of said deflecting drums engaged one set of blade courses, and the other the other set of blade courses. This arrangement achieved the specific end sought, but brought with it certain penalties. To understand these best, reference must again be directed to the simple figure 8 machine. In that type of machine, as will be quite evident, the points of natural normalcy of both blade courses comes exactly mid-way between the two blade supporting drums. The two sets of blade twisting guide means being located relatively short equal distances above and below these points of natural normalcy, they do not exert an undue strain on the blades, and there is not exerted an undue blade pressure on the guide means, such as might both heat and rapidly wear the latter. Moreover, the points of natural normalcy for both sets of blade courses coincide with one another, so that by placing the two sets of blade guide means equal distances above and below said points, what blade pressure and consequent wear and heating does occur is equally distributed between the two sets of blade guide means.

The inherent advantages of the figure 8 machine mentioned immediately above are' lost in large measure in the four drum type of machine disclosed in my Patent No. 2,143,242. Reference to said patent (Fig. 17) will reveal that one set of blade courses travels between one blade supporting drum. and one blade deflecting drum, while the other set of blade courses travels between the other blade supporting drum and the other blade deflecting drum. The point of natural normalcy for one set of blade courses is hence mid-way between one blade supporting drum and one blade deflecting drum, and for the other set is mid-wa between the other supporting drum and the other deflecting drum. Since these midpoints do not coincide, but on the contrary will be spaced apart by a distance approximately equal to the center-to-center spacing of each blade supporting drum from its associated blade deflecting drum, the points of natural normalcy for the two sets of blade courses Will fail to coincide by a like distance. Assuming typical 11 drums, and a drum spacing of say /2", there is in practice a vertical distance of about 11 between the points of natural normalcy for the two sets of blade courses. This distance is excessive, and results in the blades of each course imposing undue pressure on one set of blade guides, while the pressure on the other becomes actually lighter than could well be sustained. The desired equal distribution of heating and wear on guides and blades thus is not achieved.

My later six drum machine, disclosed in my Patent No. 2,179,659, solved all of the abovementioned problems. In this machine, the blade deflecting drum associated with each blade supporting drum was moved laterally (as compared with its position in the four drum machine) until its periphery was just outside a medial plane defined by the axes of the two blade supporting drums, and two additional blade deflecting drums were added, on the'other side-of said plane, in positions of symmetry with respect to the first mentioned blade deflecting drums. In this arrangement, both sets of blade courses were engaged top and bottom by two blade deflecting drums symmetrically located on the two opposite sides thereof, so that the blade courses were brought toward a single plane determined by the axes of the blade supporting drums, and also so that the points of natural normalcy of both blade courses came precisely opposite one another, i. e., in transverse alignment witheach other, as in the simple figure 8 machine.

However, compared with the four drum machine, the six drum machine had its own peculiar disadvantages, one of which was the undesirable cost of the two added drums and the increased power to drive them. Another disadvantage was the necessity for two additional bends in the blade path, while still another was a shortening of the blade courses, unless the outside supporting drums were spread farther apart. The six drum machine here spoken of has, insofar as I am aware, offered the best prior solution to the multitude of problems presented in this type of slicing machine, and has demonstrated its superiority in practical service. However, as mentioned, it still carries with it certain disadvantages which it is the purpose of the present invention to eliminate.

The general object of this invention is thus the provision of an improved multiple endless band blade slicing machine having none of the above-mentioned disadvantages of previously known machines, but nevertheless retains and possessesv therespective advantages of each of them.

In particular, it is an object of the invention to provide a machine requiring no more than two blade supporting and two blade deflecting drums, wherein all the blade courses approach or are nearly in a common slicing plane, and wherein the points of natural normalcy of all the blade courses come substantially opposite or in transverse alignment with one another.

These objects I have attained by a simple but heretofore unobvious modification of my earlier four drum machine consisting in positioning the two blade deflecting drums on opposite sides of but relatively close to a new reference plane that is tangent to opposite sides of the two blade supporting drums. The blade courses follow this new reference plane, and thus, as distinguished from the earlier four drum machine, the tWo deflecting drums are on opposite sides of rather than on the same side of the blade courses. The blade arrangement in the present invention involves the stretching of one blade course of each blade between the remote or opposite sides of the two blade supporting drums, and the stretching of the other blade course of each blade between the adjacent or proximatesides of the two blade deflecting guide drums. This arrangement results in the mid-points of the two courses of each blade being in transverse alignmenta most important gain over the earlier four drum machine. As will be made more fully apparent hereinafter, the present invention as thus briefly introduced secures all the advantages of the simple figure 8 machine, of the four drum machine as heretofore known, and of the six drum machine, with none of the above-outlined shortcomings and disabilities of any of them.

The present invention will be better understood from the following more detailed description taken in connection with the accompanying somewhat diagrammatic drawings representing a preferred embodiment thereof.

In the drawings:

Figure 1 is a somewhat diagrammatic view of a multiple band blade slicing machine in accordance with the invention looking in a direction parallel to the axes of the blade supporting and deflecting drums;

Figure 2 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

Figure 3 is a view taken as indicated by arrows 3-3 of Fig. 1.

. the drums being typically of a diameter of 1'.

These drums may be constructed and mounted for rotation, one to be driven and the other to idle, in any suitable or conventional manner, not necessary here to illustrate or describe. To reduce the severity of the twist of the blades, and

therefore the blade pressure on the blade guides at the slicing area, it is of course desirable to have the blade supporting drums spaced apart as far as is practically feasible, as for example, by about 12' between centers. The drums are indicated in the somewhat diagrammatic Fig. 1 as having their axes in a plane AB which is not far from vertical, though in view of the somewhat undue tallness of a machine so arranged and having blade supporting drums spaced by 12, the plane AB is in practice preferably tilted to an angle of about 30 with vertical. Of course, insofar as the broad invention is concerned, this plane could be at any angle whatsoever.

Two spaced blade deflecting drums l2 and I3, preferably, though not necessarily, of the same diameter as the supporting drums l0 nd H, are rotatably mounted between and parallel to said supporting drums, one relatively close to each of the said supporting drums. These deflecting drums l2 and 13 are located on opposite sides of and relatively close to, but still spaced somewhat from, a. reference plane MN that is tangent to opposite sides of the two blade supporting drums Ill and II.

A multiplicity of conventional endless band blades S, sharpened on one edge, are mounted side by side on the blade supporting drums l0 and H, going on said drums in the manner indicated best in Fig. 2. The band loop of each blade is first passed over upper drum It, then twisted through a half turn and finally passed over lower drum H. The blades pass the deflecting drums l2 and I3 on the sides thereof nearest the plane MN, so as to be deflected over toward said plane by. said drums, and so as to be tensed thereby. Each blade thereby forms one blade course 14 stretched directly between the blade supporting drums ill and Ii along the plane MN, and a second blade course l5 stretched between the deflecting drums l2 and I3, and

crossing the first-mentioned blade course at a relatively small angle. The two points where the first blade course Id tangentially contact the supporting drums l and H are identified in the drawings by numerals I and i7, respectively, and the two points where the second blade course l5 tangentially contact the deflecting drums l2 and i3 are identified by numerals i3 and is, respectively.

.It will be evident that in the arrangement described, the mid-points 253 of the blade courses l i (half-way points between points it and ii) and the mid-points 2| of the blade courses l5 (half-way points between points it and 59) are in transverse alignment, i. e., the mid-points 22*! and 2| lie substantially in a straight line XY parallel to the drums. that the blade courses i i and i5 are twisted into parallel positions normal to the drums, i. e., at right angles thereto, at their transversely aligned mid-points.

It has already been stated that the deflecting drums are positioned relatively close to, but nevertheless spaced somewhat from, the reference plane NM. The closer the spacing, the lesser the angle between the blade courses it and i5, and therefore the lesser is the tendency to crush the loaves. Preferably, and in the embodiment here shown, the two deflecting drums are so located that the two points it nd ill at which each deflected blade course tangentially contacts the deflecting drums lie between the planes MN and AB, thus assuring a relatively small angle between blade courses. Of course, the deflecting drums should in any case be sufficiently spaced from the plane MN to avoid contact between the deflecting drums and the courses It.

A blade twisting guide means 22 is provided to contact each blade course at two places, preferably at approximately equal distances on opposite sides of its said mid-point, to thereby form a slicing zone for the loaves L to be sliced. This blade twisting guide means 22 may be of any suitable or conventional character but is here diagrammatically indicated simply as a pair of guides 23 suitably slotted in parallel :planes normal to the drums and at the proper spacing to give the slice thickness desired. The function of this blade twisting guide means is to twist and straighten mid-sections of the blade courses into planes normal to the drums, while onl slightly increasing the severity of the twist of the blades.

Both courses of each blade having their midpoints in transverse alignment with one another, the points of natural normalcy of both sets of lade courses will similarly coincide at said midpoints, as has already been explained; and it follows that the lateral blade pressures of both blade courses will be equally distributed between the two spaced guide members 23. Thus the unequal distribution of blade pressures on the upper and lower blade guides characteristic of the four drum machine as heretofore known is It will further be evident avoided, and with this condition is avoided the previously existing excessive wear of each blade course on one of the blade guides. In this respect, the machine has all the advantages of the simple two drum figure 8 machine; at the same time, however, the advantage of the previous four drum machine over the figure 8 machine in bringing both blade courses of each blade toward a common slicing plane is retained. All of the many advantages of the previous six drum machine are retained, but with a saving of two drums, and the elimination of two bends in the blade courses. The machine of the present invention thus possesses the advantages of all of the prior art machines discussed in the foregoing, and at the same time is the first machine to be entirely free from all of the several hereinabove noted disadvantages of those machines.

I claim:

1. In a slicing machine, the combination of two spaced, parallel, rotatable blade supporting drums, two spaced rotatable blade deflecting drums mounted between and parallel to said supporting drums, one relatively close to one of said supporting drums and the other relatively close to the other of said supporting drums, said defleeting drums being located on opposite sides of but relatively close to a reference plane that is tangent to opposite sides of said two supporting drums, a multiplicity of endless band blades mounted side by side on said drums, each of said blades being looped over both said supporting drums and also being deflected toward said reference plane by both of said deflecting drums, each of said blades being also twisted through between said supporting drums, to thereby form two MSW-twisted blade courses that cross each other at their midpoints and form a small angle between them, one of said courses extending between said two supporting drums along said reference plane and the other said course extending between said deflecting drums, all in such manner that said blade courses are twisted into parallel positions normal to the drums at their midpoints and that said midpoints of all said courses lie substantially in a straight line that is parallel to said drums, and blade twisting guide means contacting each blade course at two places, one on each side of its said midpoint, to thereby form a slicing zone, said blade twisting guide means twisting said blade courses in the slicing zone into spaced parallel slicing planes that extend normal to said drums.

2. A combination as defined in claim 1, wherein the two deflecting drums are so located that the two points at which each deflected blade course tangentially contacts said deflecting drums, lie between the said plane that is tangent to said supporting drums and a plane that passes through the axes of the supporting drums.

WILLIAM WALTER HAR'IMAN.

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