| 摘要 |
A simplified sound reproducing device for randomly selecting recordings to be reproduced, having a free gear formed with one or more intermittent tooth portions with tooth crest in the direction of rotation longer than that of other normal teeth. The gear system which includes this intermittent tooth portion is constructed such that this portion can contact any one gear tooth among other normal teeth of the mating gear in the gear system including the free gear and a center gear disposed at the center of the record disc. When the swing arm approaches the end point of sound reproduction at the urging of pickup, the free gear can engage the center gear. A cam member is interposed between the record disc and sound transmitting member. The cam member has two cam pieces axially stacked one on another such that the total length of the cam member can be lengthened when the two pieces are twisted. One upper piece 7 is capable of engagement with the free gear. When the free gear abuts the crest of tooth of a gear tooth in the mating gear of the gear system in the device and stops rotation against the driving force imparted by the center gear upper cam piece also stops resulting in elongation of the cam member. Because the location of the intermittent tooth portion is unpredictable with regard to the phase of rotation of the record disc the timing for initiating twisting action in the cam member which releases the stylus force is also made random. |
