Patent Pending Blog - Patents and the History of Technology

Early Snowmobile

This is  a 1922 snow machine based on an automobile that is years ahead of Bombardier's first successful snow machine designs.  This was submitted by Dean Urevig, related to Iver Urevig the inventor.  Iver lived in North Dakota, and probably put this machine to good use there. 

Other snow machines on this blog include:

a motorized sleigh from 1913
Eliason snow sled
Bombardier snow machines
track driven roadster of 1919
screw driven snowmobile of the 1950s

The Barlow Knife

What did kids have as a toy in the days before Game Boys and Nintendo?  One thing that was prized by the boys was a knife, specifically a Barlow knife.  A Barlow knife is a style of folding knife with one or two blades, a tear drop shaped handle, and a wide bolster that reinforced the pivot of the blades, which was the part of the knife that received the most strain.  In Mark Twain's books "The Adventures of Tom Sawyer" the Barlow is noted as an admirable gift for a boy,  when...

"Mary gave him a bran-new "Barlow" knife worth twelve and a half cents;   and the convulsion of delight that swept his system shook him to his foundations.   True, the knife would not cut anything, but it was a "sure-enough"   Barlow, and there was inconceivable grandeur in that - though where the Western boys ever got the idea that such a weapon could possibly be counterfeited to its injury, is an imposing mystery and will always remain so, perhaps."

Barlow knives have been the universal pocketknife in parts of the country starting in the late 17th century.  They were made by a number of manufacturers, and were of fairly cheap construction.  They don't generally go for twelve and a half cents anymore, but can go for up to $100 or $200, like this Barlow knife made by Buck.

The Barlow Knife was also the title of a fiddle tune,  called "the Barlow Knife."  Barlow knives were carried by farmers, soldiers, colonists, trappers, explorers, mountain men, and settlers. George Washington is reputed to have loaned his Barlow knife to a teamster at the time of the crossing of the Delaware at Christmas eve before the battle of Trenton, so the teamster could light a fire.  That particular Barlow knife is still in the hands of descendents of the teamster.

Pool Cover Decking System

If you have a swimming pool, or know someone who does, you may have encountered this problem.  Powered pool covers on a roller are great for keeping debris out of the water, and to keep the water warm.  But they make one side of the pool just about unuseable.  The side that has the roller is unsupported its entire length, so it is springy, and the pool owners usually don't want you to sit on the edge because of its weakness.  Wouldn't it be nice if it could be made solid and strong enough to support people walking on the deck, sitting on the edge, and allowing that side to be used normally?  It would basically be a movable pool cover deck that offered full support, and allows you to enclose your pool cover.

A Ketchum, Idaho (home of the Sun Valley resort) structural engineer, Mike Bouiss, had an idea on how to fix that.  He built a deck that hides the pool cover, and is a rotating pool cover deck that is fully supported by a cantilevered lip, and flips open for access to the pool cover, roller, motor, and other equipment.  With the BB Deck, the edge of the pool is fully usable on the edge where that pool cover is stored, and one can walk on the rotating deck .  The deck can conceal the pool cover in a very aesthetic fashion, and provides a tray lid alternative in the form of a rotating walk on tray lid which can enclose your pool cover.  Photos and diagram are from Mike's web page, BBDeck.com.

Early Cantilever Brake

The earliest bicycles, like Lallement's bicycle, did not have brakes as such, but back pressure on the  pedals provided some braking.  Later bikes used a brake pad that pushed against the tire, like the brakes found on wagons of the day.  Later bikes used pads that pressed agains the rim of the wheel, like the centerpull brake.  Another type of brake is the cantilever brake, in which the brake arm is pivotally attached to the bike frame, with the brake pad placed between the pivot (the fulcrum of the lever thus formed) and the end of the brake arm.  This type of brake is thus a class two lever.   Although this cantilever brake is from 1939, they really became popular when added braking power was needed on bikes that were being made for off road use.

The rest of the bike technology posts are in the Bicycle Technology section.

Descending Device

This early rope descender looks it works by a similar principle as modern rope descenders, by forcing the rope to make some turns around some obstacles.

The Lighthouse at Alexandria

The Seven Wonders of the Ancient World included

The Temple of Artemis at Ephesis
The Colossus of Rhodes
The Pyramids of Egypt
The Hanging Gardens of Babylon
The Statue of Zeus at Olympia
The Mausoleum of Halicarnassus
The Lighthouse at Alexandria

When Alexander the Great died as a young man, his empire was divided up to be governed by his generals.  Egypt was governed by one of Alexander's generals named Ptolemy Soter.  Ptolemy began a lighthouse on an island called Pharos in about 290 B.C., adjacent to the harbor of Alexandria, and it was finished by his son after his death. 

The lighthouse is described as being of three sections.  The lower section was square and 184 ft in height.  The middle section was octagonal and 90 ft tall.  The upper section was circular and 24 ft high, for a total building height of 384 ft, equivalent to a 40 story building.  The core of each section was hollow and provided a circular core which was used to lift fuel to the top of the structure.  The lighthouse was the tallest structure in the ancient world.  By comparison, the tallest lighthouse in the modern world is the Marine Tower in Yokohama, which stands 348 feet tall. 

During the night a fire was kept lit, and a reflecting mirror directed the light.  During the day the reflector was used to reflect the sun for a distance of 50 km.  The reflector was removed by the Arab conquerors of Alexandria in 690 A.D.  In the 1300s two severe earthquakes made the lighthouse a ruins.  It was finally dismantled in 1490 and the stones incorporated into the walls of Alexandria by the Egyptian sultan. 

The drawing below is by Bill Munns from his site Seven Wonders of the Ancient World. 

Ultralight Tent

Here is a look at two contrasting tent styles.  The 1891 camping tent uses one central pole, four corner stakes, and two guy lines.  It has lots of headroom, and would be a comfortable tent, probably for horse packing or car camping.  The lower figure shows that this tent is a veritable hotel room, and might sleep 4.

A total opposite design philosophy is seen in the ultralight Rainbow Tent by Tarptent. This tent sleeps 1, weighs less than 2 pounds, and has one pole curving side to side, and a cross pole that forms the center beam of the tent ceiling.  If you attach hiking poles to the corners the tent becomes freestanding, but you can also just stake the corners. 

Tent with a View

Here is an interesting tent from 1891.  In fair weather the side can be opened up, and when it is raining the side rolls down for full protection.  This idea is pretty similar to some modern ultralight tents, like the Tarptent tent shown below which has a side that opens, or that can be closed by rolling down the flaps and zipping them together to form an enclosed threshold.  This tent is by Tarptent, which has a number of models that look very light and innovative.

Zeppo Marx's Cardiac Monitor

Herbert "Zeppo" Marx was the youngest of the vaudeville and movie act of the Marx Brothers.  He also had quite a mechanical inclination.  When he left the Marx Brothers, he first joined his brother Gummo in a talent agency.  Later he coinvented a wrist worn device to warn the wearer of irrigularities in heart rythms.  Thousands of these were sold.  He later developed a type of clamp for securing cargo in airplanes, and his cargo clamp was widely used by the Army Air Corps in WW II.

1896 Motorcycle, with Heated Handlebars

This nifty bicycle/ motorcycle has a motor to the rear of the back wheel, and what is exceptional about this motorcycle is that the exhaust from the gasoline engine is routed into the bike frame, so that the foot pegs and handlebars can be heated. The inventor is from Ohio, so this modification would help the motorcycle be a year around mode of transportation.

The rear wheel is driven by the actual piston rods of the gas engine, like an old steam locomotive.