preferred embodiments is not intended to indicate a desire to invoke the special provision of 35 u s c 112 paragraph 6 to define the invention to the contrary if the provisions of 35 u s c 112 paragraph 6 are sought to be invoked to define the invention s the claims will specifically state the phrases u201c means for u201d or u201c step for u201d and a function without also reciting in such phrases any structure material or act in support of the function even when the claims recite a u201c means for u201d or u201c step for u201d performing a function if they also recite any structure material or acts in support of that means of step then the intention is not to invoke the provisions of 35 u s c 112 paragraph 6 moreover even if the provisions of 35 u s c 112 paragraph 6 are invoked to define the inventions it is intended that the inventions not be limited only to the specific structure material or acts that are described in the preferred embodiments but in addition include any and all structures materials or acts that perform the claimed function along with any and all known or later developed equivalent structures materials or acts for performing the claimed function referring now to fig1 2 and 3 an entertainment system 1 contains a housing 4 and an operating control arm or arm 2 operating through an arc relative to a pivot system 5 during operation a rotational support disk 6 having a rotational center 6 a rotates relative to housing 4 arm 3 pivots through a preferred number of arc degrees relative to an edge shown and rotational center 6 a of.