In Aro Mfg. Co. v. Convertible Top Replacement Co., 365 U.S. 336, 81 S.Ct. 599, 5 L.Ed.2d 592 (1961), the Court held that the replacement of the fabric portion of a convertible car top was a permissible repair, not an infringing reconstruction. 365 U.S. at 346, 81 S.Ct. at 604-05. The Court held: "No element, not itself separately patented, that constitutes one of the elements of a combination patent is entitled to patent monopoly, however essential it may be to the patented combination and no matter how costly or difficult replacement may be." Id. at 345, 81 S.Ct. at 604. The Court also rejected the "heart of the invention test." See id. at 344-45, 81 S.Ct. at 603-04 (holding that replacement of the distinguishing part of the patented combination does not amount to a reconstruction because a patent covers the totality of the elements in a combination). The Supreme Court further explained the test for what constitutes a reconstruction: "The decisions of this Court require the conclusion that reconstruction of a patented entity, comprised of unpatented elements, is limited to such a true reconstruction of the entity as to 'in fact make a new article,' after the entity, viewed as a whole, has become spent." 365 U.S. at 346, 81 S.Ct. at 604. The Supreme Court also noted that "the consequent demand for replacement fabrics has given rise to a substantial industry." Evidence of development in the industry could also be a factor tending to prove that there is a reasonable expectation that the part of the patented combination wears out quickly and requires frequent replacement. The Court noted that the right to use a patented combination, which impliedly attaches upon the sale of a device or apparatus embodying that combination, includes the right to preserve the fitness of that combination for its intended use in so far as that fitness may be affected by wear or breakage. Aro, 365 U.S. at 345, 81 S.Ct. at 604. The Supreme Court accordingly held that the "maintenance of the 'use of the whole' of the patented combination through replacement of a spent, unpatented element does not constitute reconstruction." Id. The Court also held: reconstruction of a patented entity, comprised of unpatented elements, is limited to such a true reconstruction of the entity as to "in fact make a whole new article," after the entity, viewed as a whole, has become spent. In order to call the monopoly, conferred by the patent grant, into play for a second time, it must, indeed, be a second creation of the patented device. Mere replacement of individual unpatented parts, one at a time, whether of the same part repeatedly or different parts successively, is no more than the lawful right of the owner to repair his property. Aro, 365 U.S. at 346, 81 S.Ct. at 604. In Aro Manufacturing Co. v. Convertible Top Replacement Co., 365 U.S. 336 (1961) the Court stated the controlling inquiry governing the replacement of unpatented parts of a patented article: reconstruction of a patented entity, comprised of unpatented elements, is limited to such a true reconstruction of the entity as to "in fact make a new article," after the entity, viewed as a whole, has become spent. . . . Mere replacement of individual unpatented parts, one at a time, whether of the same part repeatedly or different parts successively, is no more than the lawful right of the owner to repair his property. (Id. at 346.)