Knox Hydraulic Pump Slide Rule
date: label: date made
content: ca 1970
name: label: maker
content: Knox, Inc.
notes: label: Description
content: This rule consists of a clear plastic envelope, glued together along the back bottom edge, and a white plastic slide. The front is marked: KNOX (/) SO. WALPOLE/W. SPRINGFIELD. MASS./BRIDGEPORT, CONN. (/) PNEUMATIC & (/) HYDRAULIC SYSTEMS & (/) COMPONENTS. By setting the force in pounds opposite the PSI of a line, a user can read the diameter of a cylinder in inches. By setting the rule to the desired diameter of a cylinder, the user reads the displacement in cubic inches opposite the length of a stroke in inches. By setting the back of the rule to a desired pump delivery in gallons per minute, the user reads the time in seconds opposite displacement in cubic inches and the velocity of oil flowing through the pipe (in feet per second) opposite the area of the pipe in square inches.
label: Description
content: Knox, Inc., manufactured hydraulic pumps. From its headquarters on Foxhill Drive in South Walpole, Mass., the company filed for trademarks in 1966 and 1968 and was assigned U.S. Patent 3,599,849 in 1971. Thus, this rule likely dates to around 1970. By 1980, the company was renamed Knox-Norton, Inc., and headquartered in Hartford, Conn.
label: Description
content: Reference: U.S. Patent and Trademark Office, <i>Trademark Electronic Search System</i>.
label: Location
content: Currently not on view
place: label: place made
content: United States: Massachusetts, South Walpole
topic: label: Subject
content: Mathematics
label: Subject
content: Rule, Calculating
label: Subject
content: Engineering
label: Subject
content: Manufacturing
setName: label: See more items in
content: Medicine and Science: Mathematics
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content: Science & Mathematics
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content: Slide Rules
creditLine: label: Credit Line
content: Gift of Pratt-Read Corporation
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1988.0795.02
label: accession number
content: 1988.0795
label: catalog number
content: 1988.0795.02
objectType: label: Object Name
content: slide rule
physicalDescription: label: Physical Description
content: plastic (overall material)
label: Measurements
content: overall: .1 cm x 16.5 cm x 7 cm; 1/16 in x 6 1/2 in x 2 3/4 in