History The diaphone horn was based directly on the organ stop of the same name invented by Robert Hope-Jones, creator of the Wurlitzer organ.Michael Lamm (Winter 2003) "Feel the Noise: The art and science of making sound alarming," Invention & Technology, 18 (3) : 22–27.Seeing the Light: "The diaphone fog signal" by Jeff Laser Hope-Jones' design was based on a piston that was closed only at its bottom end and had slots, perpendicular to its axis, cut through its sides; the slotted piston moved within a similarly slotted cylinder. Outside of the cylinder was a reservoir of high-pressure air. Initially, high-pressure air would be admitted behind the piston, pushing it forward. When the slots of the piston aligned with those of the cylinder, air passed into the piston, making a sound and pushing the piston back to its starting position, whence the cycle would repeat.For the patents of Hope-Jones' diaphones that were used as foghorns, see: Hope-Jones, R., "Sound-producing apparatus suitable for sirens, organs, etc.," British patent 26,738 (31 Dec. 1901). See: Patents for Inventions: Abridgements of Specifications … Period – A.D. 1901-4. (London, England: Patent Office, 1907) page 122. Robert Hope-Jones, "Sound-producing device suitable for sirens, etc.," U.S. patent 702,557 (filed: 26 Nov. 1901; issued 17 June 1902). A modification of Hope-Jones' design was patented by John Pell Northey, head of the Northey Co. Ltd. of Toronto, Ontario, Canada, which manufactured pumps and small gasoline engines.For further information about John Pell Northey and the Northey Company of Toronto, see: SmokStak: The Northey Co., Ltd. Buzzcoil.Brinkster.net/Northey. Northey added a secondary compressed air supply to the piston in order to power it during both its forward and reverse strokes and thus create an even more powerful sound.Northey's patents for diaphones: John Pell Northey, "Sound-producing device suitable for sirens or like instruments," U.S. Patent 736,428 (filed: 22 Nov. 1902; issued: 18 Aug. 1903). This patent mentions a second source of high-pressure air that caused the slotted piston to reciprocate. John Pell Northey, "Sound-producing device," U.S. Patent 973,960 (filed: 5 June 1908; issued: 25 Oct. 1910). John Pell Northey, "Sound-producing device," U.S. patent 976,682 (filed: 5 June 1908; issued: 22 Nov. 1910). John Pell Northey, "Sound-signaling installation," U.S. Patent 1,619,585 (filed: 8 June 1926; issued: 1 March 1927). John P. Northey, "Sound-producing device," U.S. patent 1,799,387 (filed: 1 March 1929; issued: 7 April 1931). The entire horn apparatus was driven by a compressor. To manufacture the new equipment, Northey set up the Diaphone Signal Co. at Toronto in 1903.Laser, J. Seeing the Light accessed 2008-03-09 It manufactured a range of diaphone models: the large "Type F", which created a tone of about 250 Hz, found worldwide use as a fog signal, especially in lighthouses. The mechanism of the diaphone created a noticeable low-frequency "grunt" at the end of each note produced, caused by the piston decelerating as the air supply was cut. As this low-frequency sound could carry further, Northey's son Rodney redesigned the "Type F" model to sustain the second low tone,Rodney V. Northey, "Sound-producing device," U.S. patent 1,844,226 (filed: 27 March 1931; issued 9 February 1932). creating the familiar two-tone fog signal, commonly used in lighthouses and lightvessels in the United States and Canada (as well as in a famous series of radio commercials for Lifebuoy soap). This version, known as the "Improved Type F" or later as the "F2T", was particularly common in installations on the West Coast of the United States and in lightvessels. Installations in Europe generally used single-tone diaphones.Fox, F. Diaphone at Douglas Head Lighthouse accessed 2008-03-09
History The diaphone horn was based directly on the organ stop of the same name invented by Robert Hope-Jones, creator of the Wurlitzer organ.Michael Lamm (Winter 2003) "Feel the Noise: The art and science of making sound alarming," Invention & Technology, 18 (3) : 22–27.Seeing the Light: "The diaphone fog signal" by Jeff Laser Hope-Jones' design was based on a piston that was closed only at its bottom end and had slots, perpendicular to its axis, cut through its sides; the slotted piston moved within a similarly slotted cylinder. Outside of the cylinder was a reservoir of high-pressure air. Initially, high-pressure air would be admitted behind the piston, pushing it forward. When the slots of the piston aligned with those of the cylinder, air passed into the piston, making a sound and pushing the piston back to its starting position, whence the cycle would repeat.For the patents of Hope-Jones' diaphones that were used as foghorns, see: Hope-Jones, R., "Sound-producing apparatus suitable for sirens, organs, etc.," British patent 26,738 (31 Dec. 1901). See: Patents for Inventions: Abridgements of Specifications … Period – A.D. 1901-4. (London, England: Patent Office, 1907) page 122. Robert Hope-Jones, "Sound-producing device suitable for sirens, etc.," (filed: 26 Nov. 1901; issued 17 June 1902). A modification of Hope-Jones' design was patented by John Pell Northey, head of the Northey Co. Ltd. of Toronto, Ontario, Canada, which manufactured pumps and small gasoline engines.For further information about John Pell Northey and the Northey Company of Toronto, see: SmokStak: The Northey Co., Ltd. Buzzcoil.Brinkster.net/Northey. Northey added a secondary compressed air supply to the piston in order to power it during both its forward and reverse strokes and thus create an even more powerful sound.Northey's patents for diaphones: John Pell Northey, "Sound-producing device suitable for sirens or like instruments," (filed: 22 Nov. 1902; issued: 18 Aug. 1903). This patent mentions a second source of high-pressure air that caused the slotted piston to reciprocate. John Pell Northey, "Sound-producing device," (filed: 5 June 1908; issued: 25 Oct. 1910). John Pell Northey, "Sound-producing device," (filed: 5 June 1908; issued: 22 Nov. 1910). John Pell Northey, "Sound-signaling installation," (filed: 8 June 1926; issued: 1 March 1927). John P. Northey, "Sound-producing device," (filed: 1 March 1929; issued: 7 April 1931). The entire horn apparatus was driven by a compressor. To manufacture the new equipment, Northey set up the Diaphone Signal Co. at Toronto in 1903.Laser, J. Seeing the Light accessed 2008-03-09 It manufactured a range of diaphone models: the large "Type F", which created a tone of about 250 Hz, found worldwide use as a fog signal, especially in lighthouses. The mechanism of the diaphone created a noticeable low-frequency "grunt" at the end of each note produced, caused by the piston decelerating as the air supply was cut. As this low-frequency sound could carry further, Northey's son Rodney redesigned the "Type F" model to sustain the second low tone,Rodney V. Northey, "Sound-producing device," (filed: 27 March 1931; issued 9 February 1932). creating the familiar two-tone fog signal, commonly used in lighthouses and lightvessels in the United States and Canada (as well as in a famous series of radio commercials for Lifebuoy soap). This version, known as the "Improved Type F" or later as the "F2T", was particularly common in installations on the West Coast of the United States and in lightvessels. Installations in Europe generally used single-tone diaphones.Fox, F. Diaphone at Douglas Head Lighthouse accessed 2008-03-09
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U.S. patent 702,557
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U.S. Patent 736,428
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U.S. Patent 973,960
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U.S. patent 976,682
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U.S. Patent 1,619,585
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U.S. patent 1,799,387
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U.S. patent 1,844,226