US 3742805 A
A self-contained, multi-blade package adapted to be mounted in the blade head assembly of a wafering machine comprises a plurality of substantially coextensive elongated thin flat strip blades having aligned holes in the opposite end portions thereof with spacer plates between the end portions of the blades and having holes aligned with the blade holes, and the assembly connected together by rods extending through the aligned holes and having means at the opposite ends of the rods to retain the blades and spacers assembled on the rods so that the assembly can be handled as a self-contained package for placement in and removal from the blade head assembly.
Description (OCR text may contain errors)
United tates Patent [191 Ranieri [451 July 3,1973
[ 1 SELF-CONTAINED, MULTl-BLADE PACKAGE Primary Examiner-Andrew R. Juhasz 2 Assistant Examiner-Leon Gilden  lnventor: Louis F. Ranleri, 4036 N. Central Avenue, Chicago, I. 60634 Attorney-Hill, Sherman, Merom, Gross & Simpson  Filed: Oct. 12, 1970 57] A TR T [211 App]. No; 79,947 A self-contained, multi-blade package adapted to be mounted in the blade head assembly of a wafering machine comprises a plurality of substantially coextensive 2% g i 5 83/688 elongated thin flat strip blades having aligned holes in d B the opposite end portions thereof with spacer plates be- 1 e o earc tween the end portions of the blades and having holes aligned with the blade holes, and the assembly connected together by rods extending through the aligned  Refergnces and holes and having means at the opposite ends of the rods UNITED STATES PATENTS to retain theblades and spacers assembled on the rods 3,263,669 8/1966 Ashley, 83/662 X so that the assembly can be handled as a self-contained 629,532 7/1899 Thomas 83/620 X package for placement in and removal from the blade FOREIGN PATENTS OR APPLICATIONS head assembly- 9l'5,833 1/1963 Great Britain 83/662 7 Claims, 5 Drawing Figures I "1 l I I SELF-CONTAINED, MULTll-BLADE PACKAGE This invention relates to self-contained, multi-blade assembly packages, and is more particularly concerned with such blade packages adapted for mounting in the blade head assembly of a wafering machine.
I-Ieretofore it has been the practice either to assemble the blades and spacers individually into the blade head assembly of a wafering machine, or to provide a blade package in which the blades and spacers are secured together by some sort of bonding means such as a thermo-setting or other adhesive. Both of these arrangements have serious deficiencies and disadvantages.
Where the blades and spacers are mounted as individual elements in the blade head assembly, much time and effort is consumed, parts are easily lost Further, when it is desired to invert the blades, the entire process must be repeated, to, in effect, rebuild the blade assembly. Salvaging of parts of the assembly is extremely difficult and generally ignored, even though considerable savings could be effected if salvaging of undamaged, unbroken and still usable parts were to be effected.
Since it is extremely important to attain great accuracy in spacing of the blades for uniformity of wafering results, the bonding method of attaining a selfcontained package presents a rather serious problem in that the adhesive material between the spacers and the blades can hardly be controlled to the extent that there may not be at least minute but nevertheless significant variations in spacing between the blades after the package has been clamped in the blade head assembly. In addition, the bonding technique requires special handling to effect the bonding which not only entails use of special equipment, but involves a rather costly labor problem due to the processing required, and only narrow blade packages are feasible.
According to the present invention, the foregoing and other disadvantages, defects, inefficiencies, shortcomings and problems in prior expedients are overcome by providing a new and improved self-contained, multi-blade package embodying the principles of the present invention, as will be hereinafter more particularly described.
An important object of the invention is to provide a new and improved self-contained, multi-blade package especially adapted for use in wafering machines.
Another object of the invention is to provide a simplified, efficient multi-blade-package assembly.
A further object of the invention is to provide a new and improved self-contained, multi-blade package in which full advantage of spacing accuracy of the spacer plates is attained.
Still another object of the invention is to provide a new and improved self-contained, multi-blade package for the intended purpose which facilitates salvaging of reusable elements thereof.
Other objects, features and advantages of the invention will be readily apparent from the following description of a preferred embodiment thereof, taken in conjunction with the accompanying drawing, although variations and modifications may be effected without departing from the spirit and scope of the novel concepts embodied in the disclosure, and in which:
FIG. 1 is a fragmental plan view of aself-contained, multi-blade package embodying features of the invention;
FIG. 2 is an enlarged fragmentary side elevational view taken substantially in the plane of line II-Il of FIG. I;
FIG. 3 is a side elevational view of one of the spacer plates;
FIG. 4 is a fragmentary side elevational view of one of the blades; and
FIG. 5 is a greatly enlarged illustrative sectional detail view through the aligned bolt hole area of a blade and a spacer assembled together.
Wafering machines in which a multi-blade package 10 (FIG. 1) embodying features of the present invention is adapted to be used comprise a base supporting a spaced pair of ways generally disposed in a horizontal plane and arranged to support a motor-driven blade head assembly reciprocably. Such a blade head assembly generally consists of a rectangular frame supported for reciprocation on the ways and arranged to support a suitable plurality of closely spaced parallel blades of thin strip material for wafering a piece of ingot of hard material biased upwardly against the reciprocating blades by a supporting structure. In the blade head assembly, end portions of the blades and intervening spacers are tightly clampingly squeezed together and the blades then placed under sufficient tension to maintain them stiffly spaced in their unsupported lengths during the sawing process. To prolong the useful life of the blades it is desirable to invert the blade package after the cutting edges at one face plane of the blade package have become worn. Should any one or more of the blades snap and require replacement, the remainder of the blades should be salvageable by replacement of the broken blade or blades where that is otherwise feasible, such as where the edges of the blades in the package along one face plane remain unused.
According to the present invention, assembly of the blade package into a self-contained unit is facilitated, attainment of accurate spacing between the blades to the extent that it is possible with spacers is assured, clamping and tensioning of the blades in the blade head assembly is facilitated, inversion of the blade package can be effected with the utmost ease and speed, and salvaging of usable elements of the blade package is made easy and economical. To this end, the blade package 10 comprises preferably identical elongated, hardened thin strip steel blades Ill assembled together in suitably spaced coextensive relation with spacer plates 12 intervening between the opposite end portions of the blades, and the opposite end portions and spacers maintained in assembly by means of connecting rods 13 extending therethrough. Since the function of these rods is merely to maintain the elements of the blade package assembled together in a self-contained unit they need be only as strong as necessary to resist deformation from the weight of the assembly and are desirably of as small a diameter as practicable so as to occupy a minimum of the blade and spacer area and so that aligned rod-receiving holes 14 in the blades (FIG. 4) and aligned rod-receiving holes 15 in the spacers (FIG. 3) may beas small diameter as possible to avoid weakening of the affected areas of the parts. While the rods 13 may be in the form of narrow shank headed bolts, a practical, economical arrangement has the rods, as shown, threaded at each of their opposite ends to receive a respective retaining nut 17. These nuts are driven clampingly toward one another and desirably against respective end thrust plates 18 which are of thicker and heavier stock than the spacers 12 to resist distortion but are preferably of the same dimensions in outline. As best visualized in FIG. 2 the spacers and end plates are desirably vertically elongated when related to the blades extending horizontally, and with preferably equal upper and lower portions of the coextensive spacers and end plates providing tensioning shoulders cooperative with tensioning bars or blocks in the blade head frame of the machine with which the blade package is to be assembled.
In order to attain highly accurate and uniform wafering, the spacing between the blades 11 must be accurately controlled, and this is accomplished by having the spacers 12 of as accurate gauge as practicable. However, in producing the rod holes 14 and 15 a die punching technique is the most economical. This involves driving a die punch through the material from one side whereby a slug the size of the hole desired is sheared out. This results in a relatively clean edge about the end of the opening at the face of the stock through which the punch enters, with an inevitable burr about the edge of the opening at the exit end where the punched out slug leaves the opening and the punch follows through to size the hole. In a possible exaggerated form this condition is illustrated in FIG. where it will be observed that a relatively clean edge 19, which may either be slightly chamfered inwardly is located at the punch entry end of the hole 14 in the blade 11 while a burr 20 on the opposite end edge about the opening projects away from the face plane of the blade. While the burr 20 could be removed by grinding touch-up tool or other technique, it must be remembered that the material of the blade 11 is quite hard and thin and it would therefore be rather difficult to effect deburring. On the other hand, the spacer plates 12 and the end thrust plates 18 are of heavier gauge stock and are as a practical matter made from softer steel material so that deburring is a relatively simple matter, and not likely to affected any critical temper in the material, whereas such temper is critical in the blades 11. Accordingly, it has been found quite satisfactory to solve the problem by not only deburring the edge of the hole in each of the spacers 12, and the equivalent hole in the end plates 18, but to countersink such edge as shown at 21 (FIGS. 3 and 5) to a sufficient depth to receive the blade burr fully so that the confronting surfaces of the respective blades and spacers as well as the blades and the end plates can interengage fully without any interference from the burrs 20. This is highly important because in the blade head assembly the blade package end portions are placed under strong enough compression to effect secure frictional gripping of the confronting surfaces of the spacers, blades and end plates to enable proper tensioning of the blades by stretching force applied to the spacers and end plate serving as tensioning shoulders.
For the purpose of further assuring highly efficient frictional gripping interengagement between the spacer plates and the end plates 18 and the blades 11, the connecting rod holes 15 and the corresponding holes in the plates 18 are offset toward one longitudinal edge of the respective plates to afford as'wide a gripping area between the hole and the remaining vertical edge of the plate as practicable consistent with the manner of 6 to work against in frictionally binding the blades, spacers and end plates together for efficient stretching tension on the blades through the tensioning shoulders.
Another feature that has been found advantageous in providing excellent results with the blade package 10 resides in providing a sufficient differential in diameter between the rods 13 and the aligned rod holes to assure some radial clearance, as shown schematically in FIG. 5. Through this arrangement equilized tightening of the blades is facilitated in the initial adjustments relative to the blade package in the blade head assembly of the wafering machine. As is customary, initially the clamping blocks of the blade head assembly are relatively lightly tightened against the blade assembly, whereafter the stretching devices at the opposite ends of the frame are operated to begin stretching the blades to cause the less taut blades to stretch while the more taut blades may slip somewhat relative to the spaces or end plates to attain equilized tension. Then the clamping blocks are fully tightened to completely lock the blades and the spacers and end plates frictionally into a functionally integral unit, and the stretching structures then operated to effect the final uniform tensioning of the blades.
After a time of use, the cutting edges of the blades 11 will inevitably from back frm their original plane. The blade package 10 may then be readily released and lifted from the blade head assembly and inverted and replaced to present the remaining edges for cutting.
Should one or more of the blades break as a result of tensioning or during operation of the machine, repair can be readily effected by releasing and removing the blade package 10 from the blade head assembly, removing the nuts 17 at the side of the assembly nearest the blade or blades requiring replacement, the outermost undamaged blades being removed, together with the intervening spacers, the damaged blades being replaced by new blades or at least undamaged blades and the remaining undamaged blades that were removed replaced and the nuts replaced and the blade package returned to the blade head assembly for continued use.
After the blades 11 in the package are worn out, the blade package can be rebuilt by discarding the worn blades and replacing them with new blades, reusing the spacers 12, the end plates 18 and the rods 13 with their nuts 17. Since the blade package 10 is a self-contained unit, none of the elements of the package are lost or misplaced in handling the blade package before or after mounting thereof in respect to the blade head assembly.
By virtue of the unitary nature of the blade package 10, it can be bench made at a factory or assembly bench and installed by a machine attendant quickly and easily, and replaced when necessary with a similar blade package with a bare minimum of machine shutdown time loss.
It will be understood that variations and modifications may be effected without departing from the spirit and scope of the novel concepts of this invention.
I claim as my invention:
1. A self-contained, multi-blade package adapted to be mounted in the blade head assembly of a wafering machine wherein opposite end portions of the blades are clamped for tensioning the blades, comprising:
a plurality of substantially coextensive elongated thin flat strip blades having aligned holes in the opposite end portions thereof;
spacer plates between the end portions'of the blades having holes aligned with the blade holes;
connecting rods extending through the aligned holes of the blades and spacers;
means on the respective opposite end portions of said rods retaining the blades and spacers assembled on the rods so that the assembly can be handled as a self-contained package for mounting in and removal from the blade head assembly;
said holes in the blades being punched holes whereby burrs are present on the edge at one end of the holes; and
said plates being recessed about the holes therein to receive said burrs.
2. A blade package according to claim 1 in which the holes in the plates have been punched, and said recesses being about the burr ends of the plates whereby the plates are also free from burrs and the plates and the blades are enabled to attain unhampered confronting frictional interengagement.
3. A blade package according to claim 1 in which said recesses are countersunk at the burr ends of the holes in the plates resulting from punching the holes.
4. A blade package according to claim 1, said spacer plates having opposite edges extending normal to cutting edges of the blades, and the holes in the plates being located in offset relation nearer one of the plate spacer plates between the end portions of the blades having aligned holes;
connecting rods extending through the aligned holes of the spacer plates;
means on the respective opposite end portions of said rods retaining the blades and spacer plates assembled with the rods so that the assembly can be handled as a self-contained package for mounting in and removal from the blade head assembly;
said spacer plates having opposite edges extending normal to cutting edges of the blades;
the holes in the plates being located in offset relation nearer one of the plate edges than to the opposite edges thereof whereby to afford substantial clamping area between the holes and said other edges of the plates;
said opposite end portions of the blades having aligned holes therein aligned with the holes in the spacer plates;
said rods extending through the holes in both the spacer plates and the blade end portions;
the holes in the blades being punched holes whereby burrs are present on the edge of one end of the holes; and
said plates being recessed about the holes therein to receive said burrs.
6. A blade package according to claim 5, in which the holes in the plates have been punched, and said recesses being about the burr ends of the plates whereby the plates are also free from burrs and the plates and the blades are enabled to attain unhampered confronting frictional interengagement.
7. A blade package according to claim 5, in which said recesses are countersunk at the burr ends of the holes in the plates resulting from punching the holes.
I" i i UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent NO. Dated 3,
Inventor(s) lerl It is certified that error appears in' the above-identified patent and that said Letters Patent are hereby corrected as shown below:
Column 4, line 26, "from back frm" should read --we'ar back from.
Signed and sealed this 19th day off-March 1974 (SEAL) Attest:
EDWARD M.FLETCHER, JR. C. MARSHALL DANN Attesting Officer Commissioner of Patents