Stevens, Davis, Miller & Mosher
Method of producing a tape guide device of a rotary head type video tape recorder and the product thereof
 A tape guide device of a rotary head type video tape recorder of the helical scanning system including a shoulder portion formed on an outer circumferential surface of a lower stationary cylindrical portion cooperating with an upper rotary cylindrical portion and constituting a head cylindrical drum for guiding a magnetic tape. The shoulder portion has, in a section thereof with which the magnetic tape is not brought into contact, a configuration consisting of a plurality of parabolic lines connected to one another. Alternatively, the offset portion may have a configuration consisting of curves which are such that their second differential coordinates are continuous over the entire circumference of the head cylindrical drum with respect to the fixed coordinate system disposed on the outer circumferential surface of the head cylindrical drum, or the shoulder portion may have a configuration consisting of curves which are such that the absolute value of the maximum value of the second differential coefficients is not equal to the absolute value of the minimum value thereof. 
Matsushita Electric Industrial Co., Ltd.
B G
B23Q G11B
inventional inventional
Kiyokazu Takashi Hiroyuki Haruhiko
Imanishi Ichiyanagi Ito Kitagawa