CST/BERTEL ROLLE LASER LEVELS
The C.E. Stempel Company was founded in 1885 by Karl Ernst Stempel (1863–1933) and Wilhelm Carl Ertl (1865–1940). The company’s first product was a rotary lens with a high-speed focusing mechanism, which was used for photography until it ceased production in 1936 due to lack of demand.
The company produced a wide range of products including lenses, lamps, cameras and other optical devices. In 1938 the company was acquired by the German government and renamed to C. E. Stempel & Co., Inc.. The name “Stempel” means “stem” or “lever”.
In 1941 the company changed its name again when it became part of the Curtiss-Wright Corporation (now known as Boeing). Curtiss-Wright had been manufacturing aircraft engines since 1903 and their first airplane, the Wright Flyer, took flight in December 1903.
By 1945 the company’s main business was producing military equipment such as tanks, gunships and fighter planes. During World War II they manufactured bombs and rockets for the Allies.
The company is still in business today and produces a wide range of equipment such as unmanned aerial vehicles (UAVs), military training aircraft, helicopter engines, tactical missiles, rocket launchers, and much more. At present the company holds less than 1% market share of the civil aircraft industry.
C.E. Stempel used a trademark consisting of the letters “C E S” with a small “stem” or lever rising from the bottom of the “C” and crossing the “E”. This trademark was registered by the U.S.
Patent Office on January 3, 1935.
The company started manufacturing laser levels in the early 1960s, during which time it was a subsidiary of the CV Stempel Corporation. The trademark was still the same as before except that the letters “C E S” were replaced with a drawing of a rotary laser level. This drawing looks very much like the original trademark except that the “stem” or lever which rises from the bottom of the “C” and crosses the “E” is replaced by a laser beam.
Within the laser beam is an arc which looks very much like the figure “8” lying on its side, and at the top of the arc is a small circle containing the letter “C” which stands for “C.E. Stempel”.
During the 1960s and 1970s C.E. Stempel manufactured a wide range of rotary laser levels. These included the “RLS3”, “RLS5”, “RLS7”, “RLS10”, “RLS15”, “RLS20” and the “RLS30”.
In addition to these models, they also manufactured the “PLS4 Point Leveling System”, which could be used with any of these rotary laser levels.
The rotary laser level was powered by a 6V dry cell battery and could be connected to an external 12V battery for extra power.
Rotary laser levels were generally mounted on the front of a surveyor’s tripod. They had a range of different attachments which could be used to mount different equipment such as angle heads, targeters or vertical rods.
Rotary laser levels worked by emitting a laser beam at 90 degrees to the rotary housing. There were different types of rotary laser level available. The most common one was the “single beam” type, which had a single laser beam. In addition to this there were also models which had two laser beams (these were called “double beam”) or even three.
The “single beam” types could measure distances up to 200 feet (61 meters). The “double beam” types could measure up to 400 feet (122 meters), and the “triple beam” types could measure distances up to 600 feet (183 meters).
These rotary laser levels were equipped with a horizontal circle which had graduations every two degrees. The horizontal circle was connected to the laser on a vertical rocking arm and rotated in unison with the laser.
Three types of graduations were available on the horizontal circle:
1). Graduations every two degrees. These were used to measure horizontal distances in a straight line.
2). Graduations every five degrees. These were used to measure horizontal distances when the laser level was set at an angle in order to obtain an approximate slope of the land.
3) No graduations (only a slight arc). These were used for leveling the instrument or connecting it to a plumb bob.
These rotary laser levels had a “T-Bar” attached to their top which could be used for leveling. There were also models with an angle head mountable on the T-Bar.
Rotary laser levels manufactured by C.E. Stempel all seem to have serial numbers starting with “S”, followed by a number and then another letter. For example, serial number S109981 would have been the 10,989th instrument manufactured by C.E.
The rotary laser level was initially developed by “Cole Palmer & Associates” of California as the “PALaserLevel” (PAL stands for “Professional Attachment for Laserscope”, which was the manufacturer of the transit the laser level was designed to be used with). “Cole-Palmer” became insolvent in the late 1980s and was eventually taken over by C.E. Stempel who continued to manufacture the rotary laser level under their own name.
In the late 1990s, C.E. Stempel stopped manufacturing rotary laser levels and went out of business, so if you ever see one at an auction, it may be valuable!
“Cole-Palmer” (as they were known before being taken over by C.E. Stempel) manufactured the first rotary laser level. The reason why they did not use serial numbers is because they went out of business before manufacturing them had gotten to that stage!
Rotary laser levels were manufactured in five different colors:
1). Olive Drab (Green)
2). Desert Sand (Tan)
Rotary laser levels were all high-quality instruments and were very durable. In order to manufacture them, Cole-Palmer, and later C.E. Stempel, invested millions of dollars in the necessary plant and machinery.
They also employed engineers and technicians with the expertise to make such precision instruments. The rotary laser level was sold all over the world and was a high-demand item. Before C.E. Stempel went out of business, rotary laser levels were selling for as much as $4,000 a piece, but today you may be able to get one for less than $200 if you shop around.
When the Cole-Palmer company was taken over by C.E. Stempel it was initially thought that the rotary laser level would be incorporated into the product range of C.E.
Stempel, but it was decided that it would be better to concentrate on transit levels and the rotary laser level was dropped from their product range.
Needless to say, all this make the rotary laser level a highly sought after item among land surveyors, so if you have one in your possession, you may want to hang on to it!
Other survey instruments made by Cole-Palmer and C.E. Stempel, in addition to transit levels and rotary laser levels, were:
1). The “Sigma” magnetic compass. (Cole-Palmer)
2). The “Registrator” precision distance measuring device (Cole-Palmer)
3). The “Labryntester” utility instrument for checking the internal workings of theodolites (Cole-Palmer)
4). The “VertiLab” vertical circle (C.E. Stempel)
5). The “G-2” precision angle measuring device (C.E. Stempel)
6). “Cole-Palmer” and “C.E. Stempel” both made a wide range of high-grade lenses for use in all of the above instruments.
The company known as C.E. Stempel also manufactured surveying instruments under the brand name “Duffy”.
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