APPEAL from the Circuit Court of Cook County; the Hon. WILLIAM
KANE, Judge, presiding.
MISS JUSTICE MCGILLICUDDY DELIVERED THE OPINION OF THE COURT:
Lillian Anderson, administrator of the estate of her husband, John Anderson, instituted a product liability action to recover damages resulting from the death of her husband. She named the General Grinding Wheel Company (now known as SGL Abrasives, a division of SGL Industries, Inc.) as defendant. At the close of the plaintiff's case, the defendant moved for a directed verdict. The court reserved ruling on the motion until the close of all the evidence. The defendant renewed its motion when all evidence had been introduced, but the court again reserved ruling on the motion pending the deliberation of the jury. When the jury was unable to reach a verdict, the court granted the defendant's motion for a directed verdict. The plaintiff now appeals that judgment, raising the sole issue of whether the trial court erred in granting the defendant a directed verdict.
The principal facts of the incident which resulted in John Anderson's death are largely uncontested. He was killed, on August 21, 1972, when a 30" x 2 1/2" x 12" reinforced resinoid snag grinding wheel ruptured. At the time of the accident, Anderson was employed as a snag grinder by the Commercial Stamping and Forging Company and was using the wheel to grind the flash off of a forging called a henschen wheel spindle.
The grinding wheel which disintegrated was 30 inches in diameter and 2 1/2 inches thick. At the center of the wheel was a hole, some 12" in diameter. Encircling this hole were two steel rings. These rings were to provide additional support for the wheel once it had become worn. The wheel primarily consisted of abrasive particles, bond material and filler. The purpose of the bond material was to hold the abrasive particles together; in this particular wheel, the primary bonding material was resin.
Since the wheel in question was a reinforced grinding wheel, embedded within the abrasive material were two pieces of fiberglass mesh. The function of the fiberglass was to hold the wheel together while the wheel operated at normal speeds should the wheel become cracked. In order to permit the fiberglass to adhere to the bonding material, it was impregnated with resin.
The wheel was mounted upon a double end floor grinder; the machine operated two grinding wheels and Anderson was using the wheel on the left side of the machine at the time of his death. There was an adjustable guard over the wheel and an adjustable work rest in front of the wheel. Adjustments made to the position of the guard altered the speed of the machine. An 1/8" gap had to be maintained between the surface of the wheel and the work rest. If the gap became too great the workpiece could become jammed between the wheel and the work rest.
The spindles, being ground by Anderson, were essentially conical in shape with the narrowest end being blunted. Approximately a third of the way up from the base a flange encircled the cone. Anderson was grinding the flash, or excess residue, off of the face of this flange at the time he was injured.
The assistant plant superintendent, Samuel Marich, testifying for the plaintiff by an evidence deposition, stated that the normal procedure before mounting a wheel upon a grinding machine was to "ring" test the wheel. This procedure was accomplished by standing the wheel vertically and striking it in two places, about 120 degrees apart, with a wood and rawhide mallet. The sound produced would indicate whether the wheel was good or defective. The wheel which disintegrated was mounted on August 19, 1972, by Lonnie Crawford, another snag grinder employed by Commercial Stamping. Testifying for the defendant, Crawford could not recall whether a ring test was applied to the wheel before mounting it; in fact, he did not know what a ring test was.
Crawford used the wheel for approximately 5 1/2 hours on August 19, 1972. The wheel was not used again until August 21, when Anderson began to grind the spindles. James Savage, the acting foreman in the grinding department on that date, testified that he assigned that task to Anderson. Savage set the work rest at 1/8", measuring the distance with a ruler. Savage also testified that normal operating procedures provided that a device, called a cup holder, be placed upon the work rest on each side of the grinding wheel. This device held the body of the spindle while the operator ground the flange and prevented the piece from jamming. However, Savage noted that on the machine which Anderson was using, there was a cup holder only on the left side. Savage watched Anderson as he ground the first few spindles. Anderson was using the left side of the wheel and the machine and wheel were operating normally. Savage then left. Approximately 15 or 20 minutes later he heard an "explosion." Employees at Commercial Stamping found Anderson unconscious. The pieces of the grinding wheel were scattered about and the work rest and the guard were broken off of the machine.
Following the incident, Marich gathered the pieces of the shattered wheel and reconstructed it. He determined that the wheel was 28" in diameter at the time of the accident. Marich also "tached" the grinding machine and determined that the wheel was operating at the proper speed.
Norris Yonker, a consulting engineer, testifying for the plaintiff, stated that in examining the reconstructed wheel he discovered that the wheel had delaminated in two places directly opposite from each other.
Savage estimated that before the accident Anderson had ground some 50 to 75 spindles and that this amount of work would have consumed approximately one-sixteenth to three thirty-seconds of an inch of material off of the wheel. He also stated that for this particular job, any distance over three-sixteenths of an inch between the wheel and the work rest was too wide a space from a jamming standpoint. Chester Pawlowski, the grinding supervisor at Commercial Stamping, stated that even if the distance between the wheel and the work rest is more than 1/8", the flange could not become caught.
Professor Serope Kalpakjian testified as an expert witness for the plaintiff. He is a professor of mechanical engineering at the Illinois Institute of Technology and holds a master of science degree from both Harvard University and Massachusetts Institute of Technology. His thesis for one of these degrees was on the subject of the mechanics of the grinding process. He also testified that he had been involved in approximately four research projects on the abuse and destruction of the grinding wheels. During cross-examination, he disclosed that his studies largely involved the cut-off type of grinding wheel rather than the "snag" type of wheel that Anderson was using. The cut-off wheel resembles a thick phonograph record and is used to cut such substances as pipe or concrete. In such wheels, the reinforcing material is placed on the outside of the wheel and, while the stress placed upon the cut-off wheel is essentially the same as the stresses acting upon the snag wheel, the cut-off wheels are subject to certain twisting and bending actions, which are not applicable to snag wheels.
Professor Kalpakjian was retained by the plaintiff to investigate the disintegration of the grinding wheel involved in this case. He reviewed correspondence, reports, photographs and data of other investigators. He also examined remnants of the wheel and the forging and visited the site of the incident. It was his opinion that when there is a change in the geometry of the wheel it will disintegrate. This change could be the result of an obstruction or a piece missing from the surface of the wheel, which, in turn, as the wheel spins, will cause it to jam. Kalpakjian was of the opinion that the disintegration of the grinding wheel which caused Anderson's death began when a section of the wheel delaminated along the surface of the fiberglass and flew out of the wheel while it was in operation. The space left by this piece then "caught" the spindle which Anderson was grinding, causing the jamming process to commence. The jamming process then resulted in the disintegration of the wheel. It was Kalpakjian's opinion that the wheel was defective because a section of the wheel delaminated and separated itself from the rest of the wheel, and this condition existed at the time the wheel left the manufacturer's hands.
On cross-examination, Kalpakjian disclosed that the precise nature of the defect was the weakness of the bond between the fiberglass reinforcing material and the abrasive material. He reached this conclusion because there existed such a large piece of the broken wheel which had split along the plane of the fiberglass material. He explained that:
"* * * when a piece like this breaks or a grinding wheel breaks there should be an equal opportunity for the material to break into all kinds of directions. In fact, if we looked at the rest of the pieces which comprised the original wheel, we'll find that there are five additional major pieces and from what I have seen in the photographs both black and white and in color, I do not see any of the other five pieces in fact, the rest were, I think, larger than this particular piece (the large section which broke off) none of them have separated in this manner. The other pieces left the wheel when the wheel exploded. They went all over the place and hit things, but they did not delaminate.
So, when I see a broken piece like this which, again, consistently on this plain [sic] it has separated, this is of great concern to me."
Kalpakjian stated that he did not make a chemical analysis of the bond; thus, he could express no opinion as to the materials which composed the bond. He also acknowledged that a grinding wheel could break, even in the absence of any defect, if it was subjected to a jamming incident. However, he rejected such an occurrence in this instance, primarily because he failed to find any indication on the remnants of the wheel of a force sufficiently strong to cause such an occurrence. He also did not believe that the large section could have flown out of the wheel in one piece and then delaminate upon impact with another object. He noted that the large section showed signs of ...