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DACOR Corporation was a former American manufacturer of scuba diving equipment which was founded in 1954 by Sam Davison Jr. in Evanston, Illinois as "The Davison Corporation". Its name is derived from the first two letters of his surname, "Davison," and the first three letters of "corporation". Since it's foundation. DACOR was one of the five early American diving equipment manufacturers.

Together, they were:

• DACOR
• U.S. Divers (Now Aqua-Lung)
• Healthways (Sold to Scubapro in the early 60's)
• Swimaster (Sold to Voit in the early 60's)
• Voit (Sold to AMF somewhere in the late 50's to early 60's)

DIVE DACOR

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The Professional's Choice

Cable: DIVECOR Details
Genre	Diving equipment
Founded	1954 | Evanston, Illinois, United States
Founder	Jr Samuel M Davison
Headquarters	Evanston (1955-1959) Skokie (1959-1970) Northfield (1970 - Last) , United States
Key people	Samuel Davison, Donald Davison, Robert Oslon, Wallace Mitchell, Doug McNeal, Gordie Shearer, Jerry Warner, Eric Johnson, Frank Fuentez, Vern Pedersen. Lenny Dwarkins.
Products	Scuba Equipment: Scuba Regulators, Aluminum Cylinders, Steel Cylinders, Stainless Steel Cylinders (INNOVATION NEVER RELEASED), Masks, Snorkels, Fins, Backpacks, Wetsuits, Drysuits, Seachute Jackets, B.C Vests, Nautilus CVS, Lights, Instrumentation Consoles, DIve Watches, Photo Equipment, Knives, Stingray Spearguns, Polespears, Merchandise, Bags, Flags/Floats/Lift Bags, Weight Belts, Books, Schematics, Accessories,
Website	Domain Not Operational divedacor.com

HISTORY

Davison Corporation

                                 DACOR 1954 - 1998  

Jr Samuel M Davison - Founder and President of DACOR

Legend of Diving

Sam Davison's time in Guam profoundly influenced both him and his well-known company, DACOR. His significant contributions to the sport are immeasurable. Serving as a US Marine during World War II, Sam Davison Jr. spent considerable time in the South Pacific, where his experiences on Guam left an unforgettable mark on his life. Those images left him with memories that he would never forget.

The story of DACOR begins with its founder, Sam Davison Jr. He and his fellow Marines stumbled upon a new discovery during their service on the island of Guam: Japanese underwater goggles. This discovery ignited a desire within him to capture and share the images he encountered. It became a moment that would shape the trajectory of his life. During post-World War II, Sam began experimenting with different ways of breathing under water. Sam soon became aware of WWII surplus Diluter O2 regulators that were modified for use as scuba regulators from instructions published in Do It Yourself magazines. Also, the French Cousteau – Gagnan CG45 Scaphandre Autonome regulators were being imported into America and receiving publicity in newspaper articles and other media. Inspired by the success of these products, Sam began sketching his own ideas for constructing a scuba regulator. Upon returning home from the war, he sold vacuum cleaners from 1945 to 1947. Subsequently, in 1948, he enrolled at the University of Miami to pursue engineering, yet his underwater adventures off the shores of Guam continued to exert a profound influence on him. Reconnecting with his childhood friend, Bob Olson, at Lake Michigan further fueled their shared passion for underwater exploration. Using makeshift methods like inverted buckets with air hoses, they improvised until 1950, when Davison learned of the invention of SCUBA equipment in France. Eager to adopt this safer and more efficient gear, he swiftly abandoned the makeshift apparatus. Their dreams of diving were fully realized upon discovering an article in the July 1953 edition of SCIENCE POPULAR magazine featuring "How to construct your own Diving Lung." In those early days, Sam Davison explored depths of up to 170 feet with little knowledge of decompression sickness. To fund his venture into manufacturing diving equipment, he borrowed $10,000 from his mother. Over two years, he meticulously crafted a double-hose regulator. Its innovative design caught the attention of a buyer from Montgomery Ward, who purchased ten units initially, followed by an order of 300 more. Convinced of its superiority, Davison resolved to establish his own company for its production. Thus, the Davison Corporation of Evanston, Illinois, was founded in 1954.

Sam Davison, Carl Aldrin, and Wally Mitchell

First DACOR Regulator on a tankOriginal proto-type Diving Lung (courtesy Jerry Powell)

First DACOR Regulator on a tankOriginal proto-type Diving Lung (courtesy Jerry Powell)

That same year, Sam met with his longtime acquaintance Wallace (Wally) Mitchell, who was a design engineer by profession and also very wealthy. Wally agreed to help Sam with his scuba regulator ideas. They would meet at The Superior Tea and Coffeehouse in Arlington Heights, Illinois, a Chicago suburb. As they sipped their morning coffee, they would study scraps of paper with pencil drawings of regulators that Sam had drawn. When they were satisfied with the drawings, they would sign them and would also have the waitress add her signature. They were always brainstorming over new styles of regulators. They had regulators in tank valves, a full-face mask with a built-in regulator, and many other versions they developed. There were over 176 blueprints found with their designs during this time period. They had the prototype and production designs for the first generation of regulators, which were referred to as the Lung Model R-1, sparking a surge in manufacturing activity. This regulator featured two diaphragms as well as the others that came later in the future. This strategy was adopted to avoid a Spirotechnique patent. Wallace Mitchell filed for patent #3,028,859 for an underwater breathing device in September 1955, with DACOR as an assignee, and production for the first generation series 2500 regulator began in the spring of 1955. In selecting a name for his regulator, Sam had to avoid “Aqua Lung” which was protected by the French manufacturer La Spirotechnique, and later by René Bussoz, who imported Aqua Lungs for his US Divers brand. The Northill Garrett Corporation had also entered the regulator manufacturing market and called their model the “Air Lung” but Sam kept the “Lung” connection going by calling his model the “Diving Lung,” and so it began -

The Future of Sam Davison (Resumed)

Sam worked with Wally Mitchell on the R4 and the C3 regulators, the two hose regulators that replaced the model 2500 Dial-a-Breath. He also worked with Vern Pedersen, one of the early, experienced divers and fabricators of the day. They experimented with various spring and lever combinations. He later worked with another engineer, Lenny Dwarkins, on the first single hose regulator, called the “Dart.” By all indications, he was four years ahead of Sportsways on the invention of the single hose. His drawings featured advanced downstream second stages and work on piston first stages. But for some unknown reasons, they had to wait four years to introduce them to "SCUBA” That is a question that remains unanswered, but it is possible that Sam lacked funding. however, deserves to be recognized as a forerunner in regulator design. DACOR’s first in-house engineer was Doug O’Neil, who later helped to design the "Olympic" single hose regulators. Sam came up with the original idea for the “Glo-Top” snorkel with the neon orange decal around the top of the snorkel tube. He was the originator of the larger barrel snorkel, as well. DACOR called it the “Big Barrel,” a wrap-around snorkel. Davison came home one night with one of those see-through plastic life-sized models of a human head. He played around with shapes and lengths to find a snorkel that felt just right. This was done in the kitchen, of course. He brought some clear straight tubing and bent it to various shapes with a heater. He made a few prototypes and went to Racine Quarry in Wisconsin to test them out. There was a lot of detail work, burnt hands, and a lot of rejection, but Sam wanted them to be perfect.

His experimental team comprised his sons, Gary and Jeff. One evening, he filled the bathtub with water and had his boys try out regulators. Excitedly, he called his wife, exclaiming, "Look! They can breathe underwater!" In 1960, he developed a curved snorkel designed to conform to the head. DACOR gained a reputation as the most innovative dive equipment manufacturer in the 1960s. He would often take company divers to Lake Racine in Wisconsin to field-test new equipment. Despite never being certified as a diver himself, he had a distinctive style, always bringing an inner tube with a rope and a plastic twist-top bottle containing cigarettes and blue-tipped matches, which he'd strike off his mask to light a cigarette underwater. Success didn't come instantly for the company. His philosophy was to have someone sell the products and someone else make them, often taking on both roles himself. He believed that by making the best diving equipment, his company would ultimately surpass the competition. In the 1960s, key individuals joined the company, which he considered a family. He learned Spanish to communicate with Spanish-speaking workers and organized "taco days" to foster camaraderie. Mike Martin, who started in the repair department in 1973, eventually became head of regulator production and later transitioned to a sales role. By the mid-1970s, DACOR was a prominent name in SCUBA equipment worldwide, yet Sam Davison remained relatively unknown, preferring to let the products speak for themselves. He was a dedicated worker, often working late into the night and maintaining an open-door policy for employees and friends. Outside of work, he was a skilled pilot, glider pilot, licensed captain, and passionate photographer

Sam had a close friendship with Mel Fisher, the renowned treasure hunter who famously discovered the Atocha off the Florida Keys, unearthing one of the most valuable treasures ever found. Sam used to provide Mel with DACOR equipment for his dives, which served as effective advertising for the company. When Mel found the Atocha, he immediately contacted Sam, and they met at the site. Shortly after this encounter, DACOR's Shipping and Receiving Department received ballast stones from the Atocha, securely wired to pallets. Sam arranged for all the stones to be shipped to DACOR's home office, where he constructed a wall in the lobby using these historic stones. At Portage Quarry, a visiting diver from Chicago mentioned acquiring ballast stones from a contractor dismantling the DACOR building, illustrating the rich history behind them.

The Andrea Doria wreck has long been revered as the Mt. Everest of diving destinations worldwide. DACOR's hyperbaric chamber was utilized by divers at the wreck site and was made available to the wider dive community. Sam's passion for innovation was evident in his excitement for new equipment. He insisted that all key personnel at DACOR were experienced divers and that any item sold had to meet their rigorous standards for quality. Sam's family played integral roles in his business, reflecting his commitment to family values. His son, Gary, played a crucial role in sales, and Jeff, served as an engineer for the company, Throughout Sam''s entire career, his wife, Joan, and his sons Gary and Jeff, worked alongside him. Jeff laater became president of DACOR. -

In August 1987, Jr Samuel M Davison passed away from lung cancer.

In 1998, DACOR merged with Mares, altering its identity from the original company established prior to 1987. From 1999 onward, DACOR operated under Mares management until 2006, when DACOR vanished from the industry.

The Davison Corporation name still lurks on its way with collectors items and its regulators in use. This year (2024) marks its 70th Year Anniversary.

Everyone who cherished Sam and the DACOR family would undoubtedly wish for the company to return for its groundbreaking reputation and innovations in the scuba industry.

DACOR, remembered with excellence in the diving industry, has ascended to legendary status alongside its visionary founder, Sam Davison. Renowned as "The Professional's Choice," DACOR was a company of "divers for divers." Embodying a commitment to unparalleled quality, expertise, and sophisticated innovation.

"DacorForever: Honoring Sam and his Team's Legacy

DACOR REGULATORS |Model's R & C|Dart| Olympic| PACER*|

Evolution of Regulator Innovation

1950's DACOR

DACOR DIVING-LUNG model R-1

In 1955, DACOR began the production of their first regulator, called "Diving Lung R-1," sparking a wave of manufacturing. This regulator had two diaphragms and a vane in the airflow to control how much air the diver got. Back then, people thought that making divers breathe harder would make them use less air, but later they found out that wasn't true. But interesting enough, this was the first "Adjustable" regulator ever made. DACOR would have three model versions of the series 2500 regulator during a seven-year production period from 1955 to the end of 1961. All three models used the same two-stage pressure block, the same case body, case cover, exhaust spacer, springs, levers, and diaphragms, which left the three models with very few differences. The R-1 is a two-stage pressure reduction system with two mechanical levers to activate flow. The unique design using two low-pressure diaphragms would become the trademark and strong sales feature for most of DACOR’s two hose regulators. During the design phase for the regulator, Sam had a problem with the exhausting air in the breathing cycle. Cousteau-Gagnan had a patent for their exhaust design, and Sam did not like the method used in the Northill "Air Lung" where the exhausting air mingled in the same chamber as the inhaling air before exhausting out through a mushroom valve, creating a potential problem for water contamination. Sam’s answer was to have the chambers separated via two diaphragms. The first diaphragm was to seal out water from the inhalation chamber and activate the levers on inhalation. The second was to sense increased water pressure and transfer that pressure to the first diaphragm. Additionally, a mushroom valve was placed in the center of the diaphragm for exhaling air from the diver. An afterthought was that the regulator now had a double protection feature and DACOR would use that as a major selling point. Air entering the regulator from the tank valve was filtered by two screens and a perforated brass metal disc. The exterior parts of the regulator were finished in brushed nickel chrome, and a black painted nameplate was riveted to the cover. The nameplate reads, “DIVING LUNG", 2 stage regulator, Dacor Corporation, Evanston, ILL.” followed by the serial number. The main body case, diaphragms and cover were clamped together via six screws and nuts. The hoses were very soft and pliable, and only 17 inches long, with one inch and one and a quarter inch openings. Hoses were attached to the regulator and mouthpiece with tinnerman clamps. All DACOR model two hose regulators used tinnnerman clamps. The mouthpiece assembly had an off-center mouthpiece design, for which DACOR held patent rights.

DACOR Seeks NAVY Approval

With production underway, DACOR sought to expand its market by getting its regulator approved by the U.S. Navy. DACOR regulator serial number 588 was submitted to NEDU, but the official report stated that it failed. As the first report was not favorable, DACOR requested further evaluation of the apparatus, and in April 1956, after some adjustments, regulator 588 was re-submitted along with a second regulator serial number 923. This time, the NEDU report stated that “the DACOR "Diving Lung"" demand regulator meets EDU laboratory criteria of suitability for the use in the Naval service.” Some comments were made that the small check valves on either side of the mouthpiece were too small and restrictive, but were marginally acceptable. DACOR could now include “Navy Approved” to their credits and use the term in their advertisements. Verified serial numbers to date for the first generation series 2500 Model R-1 are numbers 588 to 1,646. This takes into consideration the two regulators verified in NEDU test report. These figures equate to 1,058 regulators, with a probable 1,500 regulators made by the end of 1955. Since no regulators have surfaced with a serial number below 1,000, one can’t help wondering where the low-serial-numbered regulators went. Since only serial numbers in the 1,000 bracket have been found, I will only consider those in the total count for the collector. Verified serial numbers range from 1,183 to 1,646, which equates to only 463 regulators, with a probable total of some 500 manufactured. This explains why we very seldom see an R-1 regulator come up for auction.

DACOR DIVING-LUNG model R-2

The model R-2 regulator was introduced in January 1956 and would continue in production until early in 1959. The R-2 was essentially the same as the R-1 but with some minor changes. The first and most notable was the label, which now read “DACOR, DIVING LUNG, double diaphragm, 2 stage regulator, Dacor Corporation, Evanston, ILL.” followed by the serial number. Next were the hoses, which were now made with crush proof ribbing, making the hoses stiffer but still pliable enough to not interfere with a diver’s side-to-side head motion. The hoses had also been increased in length to 20 inches. At some point during the year, DACOR replaced the three - piece inlet filter system with a single filter screen (sinter metal). Verified serial numbers to date for the second generation series 2500 model R-2 regulator are, numbers 2,140 to 7,756. This equates to 5,616 confirmed regulators manufactured, with a probable 6,000 made over the three-plus years of production. Since no regulators with serial number under 2,000 for the R-2 regulator have so far been located, it is presumed that DACOR started the R-2 regulators with serial number 2,001.

DACOR DIVING-LUNG model R-3 "Dial-A-Breath"

The last model for the series 2500 was the R-3, which was nicknamed the “Dial-a-Breath” and introduced in April 1959. A small adjustable vane (butterfly valve) was added in the path of inhaling air to the already proven R-2 regulator. The principle was that the airflow could be slowed or maximized depending on the diver’s need. This could be done by either presetting the vane direction before a dive or by reaching back and turning the knob during the dive. The low-pressure seat and lever assembly were rotated 90 degrees to inject air at the intake opening and around the butterfly dial-a-breath assembly. All other features for the model R-3 were the same as the model R-2, including the label. During 1961, DACOR introduced a new mouthpiece with larger one-and-a-quarter-inch check valves, and hoses that were increased in size on one end to accommodate the larger mouthpiece and secured with tinnerman clamps. So for collectors of DACOR regulators, it is likely that you may find a late serial number R-3 regulator with the newer hoses and mouthpiece assembly. The exterior finish of the “Dial-A-Breath” regulator was brushed nickel chrome as were the previous models, but several regulators at random times of production were finished in polished chrome. I have verified four of these to date: serial numbers 18,900, 30,328, 30,331 and 30,971, making these models an extra novelty. The “Dial-A-Breath” regulator would remain in production for nearly three years ending in December 1961. Serial numbers continued in sequence with the ending of the model R-2. To date, verified serial numbers for the series 2500 model R-3 are numbers 7,876 to 34,068. This equates to a whopping 26,192 confirmed regulators manufactured with a probable 27,000 made over the three year period.

(1960's)

DACOR MODEL R-4

By 1962, DACOR had almost eight years of success, and it was time for a major makeover for their 2500 series two hose regulator designs. With access to new technology and a wealth of manufacturing experience, DACOR went back to the drawing boards, made several major changes to the internal workings of the regulator, and produced the R-4 series. They added more adjustment features for fine-tuning the high pressure and intermediate pressure settings and completely changed the second stage valve, poppet assembly, and levers. They also moved the location of the low - pressure spring, and added an adjustment screw for fine-tuning and lever height adjustment. By adding more ports for filling the inhalation chamber, they also increased the air flow to the diver. The R-4 regulator maintained the double diaphragm system, and the adjustable vane (dial-a-breath) feature. The newer design large mouthpiece and hose assembly patented in 1961 was used on this model and all future models. The label got a make-over as well, and now reads “Double Diaphragm, two-stage regulator, DACOR, Model R-4, Dacor Corporation, Evanston, ILL.” followed by the serial number. The R-4 regulator would have an 11-year run, from 1962 to the end of 1973, which would be the longest of any of the DACOR model two hose regulators. During those 11 years, DACOR. would move their plant twice. The first move was to Skokie, ILL. and then later to Northfield, ILL. I have never located or seen an R-4 label with the Skokie address, but labels with the Northfield address start to appear in 1970 at around serial number 7,000. The famous dial-a-breath feature was eliminated in 1966 at around serial number 3,500, and the exterior finish would change from brushed nickel chrome to polished chrome in 1963 at around serial number 1,650. One gold-plated R-4 regulator with the serial number 1,111 was presented to DACOR to celebrate the start of a new generation of regulators. To date, verified serial numbers for the Model R-4 regulator are 1,057 to 9,162. This equates to 8,105 confirmed regulators, with a probable total of 9,000 manufactured over the 11-year production cycle.

DACOR Grew to Become a major scuba diving manufacturing company

As a young company in the expanding field of scuba equipment manufacturing, DACOR would survive through the trial years of the 1950s, and expand during the decade of the 1960s, when it would become one of the major players in the fields of innovation and safety in that industry.

DACOR Dart

MODEL C-2 “CLIPPER”

In 1963 DACOR introduced two models to their two hose regulator lineup: the R-4 and the new C-2. The patent protection held by Cousteau and Gagnan for the exhaust system design in the Aqua Lung had run its course and now could be copied. In producing the C-2, DACOR took the basic R-4 and kept the dial-abreath feature, but removed the cover, exhaust diaphragm and exhaust chamber, and replaced them with a new cover and a duckbill exhaust valve. They called this new model the CLIPPER C-2. The front cover was now larger and boxier in shape so the main inhalation diaphragm also had to be changed in shape from the R-4. They also added a rubber spacer ring just under the cover to take up the slack where the second exhaust diaphragm would have gone. On the cover face, a small red CLIPPER label was placed at the top, and a blue WORLD symbol label at the bottom, giving the regulator a unique look. The black label read, “Two stage, regulator, DACOR, model C-2, Dacor Corporation, Evanston, ILL.” followed by serial number beginning with prefix C. The regulator had a polished chrome finish and came with the same hoses and mouthpiece assembly as the R-4. The CLIPPER C-2 would have a three-year production run from 1963 to 1965. I have noticed a void in the sequence of the serial numbers for some unknown reason. No CLIPPER C-2 regulators with serial numbers in the 2,000 series have yet to be located, so the only verified numbers in the 1,000 and 3,000 brackets will be counted. To date, verified serial numbers for the CLIPPER C-2 regulator are C-1,024 to C-1,981 and from C-3,058 to C-3,985 for a verified number of 1,884 and a probable of some 2,000 manufactured over the three-year period.

MODEL C-3 “CLIPPER”

In 1966 DACOR introduced the model C-3 CLIPPER regulator, which replaced the model C-2 CLIPPER. The main body and internals remained the same, with the exception of the dial-a-breath feature. That was now fixed in position and no longer usable, and the dial-a-breath sticker was removed from the regulator. A year later, the entire dial-a-breath assembly (exterior) parts were removed and the interior butterfly was soldered in place. DACOR also eliminated the dial-a-breath feature from the model R-4 regulator that same year. The front cover had a new more streamlined shape, and this time it was adjusted to fit without having to use the rubber spacer as in the C-2 model. The CLIPPER and WORLD tags noted on the C-2 model were eliminated and the black label read; “CLIPPER, two stage regulator, DACOR, model C-3, Dacor Corporation SKOKIE, ILL.” followed by the serial number beginning with prefix C. Sometime in 1970, around serial number 4000, the address would change from Skokie to Northfield, ILL. It is worth noting that the model R-4 also changed address that year. The CLIPPER C-3 would be the only two hose regulator to have the Skokie address displayed, and would have an eight-year run, from 1966 to 1973. Confirmed serial numbers with the Skokie address are C-1,041 to 4,267, and regulators confirmed with the Northfield address are from C-4,948 to C-6,376. This equates to a total of 4,654 regulators, with a probable number of 5,000+ manufactured during the eight years.

DACOR Olympic

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(1970's)

.reference Best of the Best - 72' Olympic AFD, 76 Nautilus CVS, and 78' -

(1980's)

Reference: 79' PACER, 86' and 72' 87' (Golden age of Dacor) -

(1990's)

.reference changes

(2000's)

reference Dacor in disguise

REGULATOR EVOLUTION

Double-Hose Regulators

1978 | Model C-3NB | A "Balanced" double hose regulator that was never released

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Single-Hose Regulators

199? - 199? | ENDURO

A Dacor open-circuit scuba diving system named DaCor was patented by Dacor, e.g. see U.S. patent 3,128,481 (a safety float, in 1955 by Sam Jr, founder and president.

References

Star Wars sound designer Ben Burtt around 1977 used a Dacor Dart scuba regulator to create the heavy breathing of the notorious antagonist Darth Vader.