US3011334A

US3011334A - Material hardness grading device

Info

Publication number: US3011334A
Application number: US770330A
Authority: US
Inventors: Paul R Gjertsen
Original assignee: Individual
Current assignee: Individual
Priority date: 1958-10-29
Filing date: 1958-10-29
Publication date: 1961-12-05
Anticipated expiration: 1978-12-05

Description

Dec. 5, .1961 P. R. GJERTSEN 3,011,334

MATERIAL HARDNESS GRADING DEVICE Filed Oct. 29, 1958 2 Sheets-Sheet 1 [NV EN TOR. P R, GJERTSEM.

Dec. 5, 1961 Filed Oct. 29, 1958 P. R. GJERTSEN MATERIAL HARDNESS GRADING DEVICE 2 Sheets-Sheet 2 INVENTOR. PAUL R. GJERTSEM- United States Patent 3,011,334 MATERIAL HARDNESS GRADING DEVICE Paul R. Gjertsen, 8618 Dearborn Ave., Detroit 17, Mich.

I Filed Oct. 29, 1958, Ser. No. 770,330

6 Claims. 01. 73-7 This invention relates to the grading of the hardness of materials, and more particularly to a material hardness grading device.

It is an object of the present invention to provide a grading device which determines the hardness of various materials by a wearing action.

It is an object to provide a hardness grading device particularly adaptable in the field of ceramics as applied to the abrasive industry in connection with grinding wheels,

honing stones, etc.

It is another object to'provide in the grading device, a vertically slidable head and clamp from which depends a blade of suitable material of predetermined hardness. The grader also includes a horizontally reciprocal slide carrying a vise in which the article to be tested is secured, and wherein the vertically adjustable blade bears against an edge of the article during reciprocal movernents thereof. 7

' It is still another object herein to provide a novel form of material hardness grading device wherein the article to be graded is reciprocated against and transversely of the edge of a blade of known hardness, and wherein the wearing action under a predetermined load for a predetermined number of reciprocations of the article effects a downward movement of said blade into the article, a

' measurable distance proportional to its hardness.

These and other objects will be seen from the following specification and'claims in conjunction with the appended drawing in which:

FIG. 1 is a front elevational view of the present material hardness grading machine.

I FIG. 2 is a section taken on line 2-2 of FIG. 1.

FIG. 3 is an elevational view showing a different form of head mounting.

FIG. 4 is a fragmentary plan view thereof.

It will be understood that the above drawings illustrate merelya preferred embodiment of theinvention and that other embodiments are contemplated within the scope of the claims hereafter set forth.

Referring to the drawings, the present material hardness grading machine includes base 11 and projecting'upwardly therefrom column 12 secured thereto byv Welding as at 13.

Forwardly extending top platform 14 is secured adjacent the upper end of column 12 as by welding at 15; and

spaced therebelow in parallel relation is forwardly ex tending bottom platform 16 secured to saidcolumn as by welding 17.

A pair'of opposed upright inwardly directed guides 18 are secured to forward edges of

plaftorms

14 and 16 as by the welds 19 providing a rigid structure. Each of said guides includes an inwardly directed channel 20 within which is slidably positioned the respective opposite edge of vertically adjustable head 21.

Counterbalance lever 22 is pivotally mounted intermediate its ends upon pin 23 supported between uprights 24 secured at 25 to top platform 14. The forward end 26 of lever 22 has an upright slot 29 through which loosely projects threaded stud 27 whose lower end is secured down into head 21 as at 28, FIG. 1. Nut 30 and lock nut 31 are threaded over the upper end of stud 27 operatively engaging the top of lever 22.

' Control bar 32 is arranged above and is secured to lever 22 in parallel relation, and has mounted thereon the slidably adjustable weight 33, which on adjustment v 3,011,334 Patented Dec. 5, 1961 is suitably secured thereto as by the welds 35, FIG. 1.

Clamp 34 is undercut at 36 to cooperatively receive clamping plate 37 which is mounted over the forwardly extending studs 38 carried by clamp 34. Plate 37 .is secured thereto by the wing nuts 39, with the elongated blade 40 interposed between clamp body 34 and clamping plate 37.

Blade 40 is of a suitable predetermined and known abrasive material and has a predetermined surface roughness on the lower wearing edge thereof adapted for engagement with a workpiece or blade W, the hardness of which is to be graded in the present machine. The hardness of blade 40 is known.

Rearwardly extending plate 41 is secured at 41 to head 21 and overlies one side of top platform 14, as shown in FIG. 1. Disc 42 is eccentrically journaled at44 .upon platform 14 at one end thereof and has an elongated handle 43, whereby rotation thereof in a clockwise direection, as in FIG. 2, will cause raising of head 21. This is advantageous in setting up the machine for a grading operation. Locking arm 45 is pivotally mounted at 46 upon the undersurface of platform 14 adjacent handle 43'and may be swung outwardlyin a horizontal plane for supporting and retaining handle 43 in an elevated head lifting position so that said discvneed not be retainedmanually.

Mounted below head 21 are opposed pairs of longitu dinally spaced upright supports 47 secured at 48 to base 11, and carrying at their upper ends the transverse elongated parallel guides 49. These have interior opposed grooves 50 slidably receiving horizontal slide, 51. J

Elongated rackgear 52 is secured as by welding to the central undersurface of slide 51, and is in mesh with pinion 53 on driveshaft 54 projecting from electric motor 55. Said motor is mounted on base 11 and is retained thereon by securing strap 56 and holddown bolts 57;

A pair of upright limit switches 58 are mounted upon base 11 spaced outwardly from supports 47. These carry upwardly projectingrollers 59 in the form of actuators for said limit switches. These actuators lie in the hori-. zontal path of movement of" slide 51. Upon engagement of said slide with one of said actuators, the corresponding limit switch causes a reversal of the drive of'the electric motor 55. Accordingly,'horiz'ontal slide 51 is adapted for continuous reciprocal movement between limit switch actuators 59, for a predeterminednumber of reciprocations.

A central upright support 60 projects from and is' secured to,slide 51 and carries thereon the upwardly inclined U-shaped vise'61. Said vise includes pressure screw 62 which operatively engagesclamping plate 63 for securing the work or bladeW against the opposing stationary grip of vise 61, and includeslock nut 64. The blade or article whose hardness is to be graded is of a ceramic or abrasive material and is elongated and rectangular in shape as shown in FIG. 2, for illustration.

The article W extends transversely of the elongated horizontally disposed test blade 40 of known hardness.

The work W may represent an actual blade or merely the material from which a grinding wheel or honing stone is to be formed. In operation, the head 21 is vertically movable inits guides 18 but in limited amounts. The slide 51 and the vise mounted work W is horizontally reciprocal under the drive of reversible motor 55, Vertical head 21 is lowered manually on release of arm 45 until blade .40. rests on the article W to be tested. Thehorizontal slide is then reciprocated causing the material tested to be pulled across blade 40.

Horizontal slide 51 has controlled movements in view of the limit switChes S S and will have a predetermined number of reciprocations. This relative movement will cause the blade 40 under predetermined load to wear down into the material W, thereby indicating by the depth of the wear its hardness. This downward wear causes a corresponding downward movement of slide 21 which is measured by dial indicator 72.

For this purpose, upright support 65 is'mounted upon the top of head 21 upon one side thereof and is interiorly threaded t-o adjustably receive therein headed screw 66. Elongated upwardly inclined arm 67 has a downturned end 68 pivotally connected as 69 to the upright extension 70 upon one side of column 12, as shown in the drawings.

Arm 67 at itsupper end terminates in the upright 71 to which is secured dial indicator 72 by fasteners 73. Said indicatorincludes the usual dial 74 and movable pointer 75 for indicating the amount of vertical movement of plunger 76 which depends therefrom in a conventional manner. At the beginning of the operation plunger 76 restsupon headed screw 66 as shown in FIG. 1, and the indicator pointer 75 is set to zero. The pivotal mounting 69 of indicator support arm 67 is sufficiently tight so that arm 67 is self supporting, and plunger 76 responds to downward vertical movement of screw 66 on head 21 to thereby give a visual indication on dial 74 of the extent of downward wearing movement of blade 4%- into the work W at the point of contact 78, shown in FIG. 1. Arm 67 rests on stp 79.

V Stop arm 77 is secured across the top of extension 70 and projects inwardly thereofwhereby the dial Supporting arm 67 may be swung in a clockwise direction when not in use, being limitedin its movement by stop 77.

Accordingly, dial indicator 72 will provide direct readings of the exact depth of wear into the article being tested, thereby iudicatingits hardness in accordance with predetermined standards. Since the weight of the vertical head 21 is what exerts the downward pressure of blade 4%, and'since the pressure on the blade has a direct effect on its Wearing quality with respect to the work, said vertical head is equipped with the adjustable counterweight22-33 above described.

In thismanner, the blade 40- may be given such pressure as is best suited to. the article being tested. It has been established that the surface roughness of the lower edge of blade 40 has a very definite effect on its wear into the article tested. Therefore blade .40 should be used only once, and thereafter resurfaced to a standard degree of conventional roughness.

This is done by pulling the cutting edge of blade 46 across the face of a diamond impregnated cup wheel or similar device each time the blade is used. It has been found extremely important that the stones used in the manufacture of grinding wheels, honing stones or the like be graded for determining their exact hardness, since the use of ungraded stones of unknown hardness will result in a large number of rejects for a given honing or grinding operation.

The following data shows the importance of employing stones of known hardness. Hereunder is a copy of a report on tests conducted by the Bower Roller Bearing Co., of Michigan, and wherein variably graded stones were used. The articles honed were rollers for roller bearings /8 inch in diameter by /2 inch length and under Since ungraded stones could result in any of the above cordingly FIGS. 3 and 4 illustrate a slightly different form of head mounting designed to minimize friction.

instead of opposed upright guides 18 shown in FIGS. 1 and 2, there is mounted forwardly of platforms 1'416, the upright mounting plate 80 suitably secured thereto as by welding, similar to the welds 19 in FIG. 2. Said plate on its opposite sides includes upright edges 81 and the central upright key 82.

Opposed spaced uprights 83 are arranged upon and against opposite sides of mounting plate 8t and have corresponding internal grooves to cooperatively receive keys 82. Said uprights are secured to platesfiby a series of spaced fasteners 84.

Uprights 83 extend forwardly of plate 80' and have formed therein the opposed inwardly directed upright grooves 85. Vertically adjustable head 21' is positioned between uprights 83 in spaced relation and includes in its outer upright edges the outwardly directed grooves 86 in opposed registry with grooves 85 respectively. Vertically spaced upright rollers 87 are interposed between head 21 and uprights 83 and movably nested within the

respective grooves

35 and 86 for guidably positioning head 21, and for facilitating its vertical adjustments with a minimum of friction.

Studs 88 are secured upon opposite sides of head 21 and project laterally thereof to extend'supportably below the respective rollers 87 for maintaining the same against vertical displacement relative to head 21. Said head terminates in clamp plate 34 secured thereto at 35', being recessed at 36' to receive a blade, like blade 40 of FIG. 1.

At least one upright side of mounting plate 80 is ground on an angle of approximately one-half of one degree so as to extend upwardly and inwardly. Upright 83 is vertically adjustable relative to said tapered surface. Accordingly, any such vertical adjustment relative to mounting plate 80 brings said upright closer to the other upright resulting in a preloading' of rollers 87 to any desired amount. j Having described my invention, reference should now be had to the following claims.

I claim:

1. In a material hardness grader, a platform base, an upright column thereon, a framework securedto and pro-, jecting forwardly of said column above said base, an upright vertically movable head guidably mounted upon said framework, a clamp at the lower end of said head, a horizontally disposed abrasive blade of predetermined hardness secured in said clamp parallel to said column, a horizontally reciprocal slide mounted on said base below said 1 head, movable lengthwise of said blade, means'to reciprocate said slide, a vise secured upon said slide adapted to suuportedly mount an abrasive material of unknown. hardness, said vise so mounted as to position said material transversely below and against the undersurface of said blade, said blade resting upon said material and wearing down thereinto at one point along its length after a predetermined number of reciprocations of said slide "and material to be tested along the length of the blade, effecting corresponding downward movement of said head, and an indicator mounted on said framework having a vertically movable plunger engageable with and responsive to vertical movements of said head, the extent of such vertical movement indicating the degree of hardness of said material in accordance with predetermined standards, the arrangement of relative movement between the material tested and the testing blade providing for a series of limited cuts into the Work at points throughout its length to test for uniformity of hardness.

2. In the hardness grader of claim 1, a counterbalance for said head to regulate its downward thrust, consisting of a lever pivotally mounted intermediate its ends upon said framework above said head, at right angles thereto and at its forward end connected to said head, a load sup port joined to the other end of said lever extending above and parallel thereto, and a weight slidably mounted on said load support.

3. In the hardness grader of claim 1, the mounting of said indicator including an upwardly and forwardly inclined bracket arm secured at its lower end to said column, said arm including the upright extension to which said indicator is secured in vertical alignment with said head, said arm being swingable upwardly, and transverse stops retainingly engaging said arm respectively in use and in raised position.

4. In the hardness grader of claim 1, a horizontal lift arm secured to said head and extending rearwardly above said framework, an upright manually rotatable disc eccentrically journaled upon the side of framework normally spaced below said arm and upon rotation adapted to cam against and lift said arm and head relative to said framework, a handle on said disc, and a lock arm pivotally mounted on said framework horizontally swingable to supportably engage said handle in head elevating position.

5. In the hardness grader of claim 1, the mounting of said head upon said framework including a pair of spaced uprights secured to said framework and having therein head opposing said first grooves respectively, vertically spaced rollers loosely positioned within the opposed grooves on opposite sides of said head guidably engaging said head, and an upright mounting plate supportedly securing said uprights, at least one of its sides engaged by an upright being inclined upwardly and inwardly, vertical adjustment of at least one of said uprights bringing the same closer to the outer upright for preloading said rollers.

References Cited in the file of this patent UNITED STATES PATENTS 1,824,483 Hubmann et al. Sept. 22, 1931 2,093,650 Sunnen Sept. 21, 1937 2,175,173 Batohelder Oct. 10, 1939 2,330,578 Harris Sept. 28, 1943 2,335,235 Clifton Nov. 30, 1943 2,376,155 Kratzer May 15, 1945 2,662,397 Goldberg et a1 Dec. 15, 1953