MITCHELL CONTRACTIBLE FILM SPOOL
Mitchell Camera Corporation, West Hollywood, California 1929
The Mitchell Contractible Film Spool was introduced in November, 1929 with Mitchell advertisements also referring to it as a "contractible magazine spool".
Its purpose and function are best described by quoting an announcement from The International Photographer, November, 1929: "In these days of leather and fabric bitts the take up roll is usually wound tightly and as the rolls are now of 1,000 foot length it presents a vexatious problem to remove the spool from the film without damaging the film more or less. With the new spool this trouble is overcome. The circumference is made of spring steel and a hinged key forces this open, increasing the diameter slightly, when the spool is pressed on the magazine spindle. This action also locks the end of the film securely which has been inserted in the slot. Upon removing the spool from the magazine it contracts and may easily be removed from the film."
George A. Mitchell filed his patent application for its design on May 8, 1929, with Patent No. 1,838,432 being granted to him on December 29, 1931. The patent was assigned to the Mitchell Camera Corporation, a corporation of Delaware:
Source: U.S. Patent and Trademark Office
Ad from The International Photographer, November, 1929