Stage for transparency projection

Latest Instructo/McGraw-Hill, Inc. Patents:

Skip to: Description  ·  References Cited  · Patent History  ·  Patent History
Description

FIG. 1 is a top perspective view of a stage for transparency projection showing our new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a right side elevational view thereof;

FIG. 4 is an inverted bottom plan view thereof;

FIG. 5 is a right side elevational view thereof; and

FIG. 6 is a front elevational view thereof.

Referenced Cited
U.S. Patent Documents
3269261 August 1966 Porter
3537792 November 1970 Furniss et al.
3544211 December 1970 Albee, Jr.
3642359 February 1972 Kitch
Foreign Patent Documents
1518275 July 1978 GBX
Patent History
Patent number: D256023
Type: Grant
Filed: Dec 1, 1977
Date of Patent: Jul 22, 1980
Assignee: Instructo/McGraw-Hill, Inc. (Paoli, PA)
Inventors: Paul Constantine (New York, NY), Melvyn Ettinger (East Meadow, NY), Harry S. Rubin (Willow Grove, PA)
Primary Examiner: Catherine E. Kemper
Attorney: Harvey W. Mortimer
Application Number: 5/856,414
Classifications
Current U.S. Class: D16/26
International Classification: D1602;