Liquid level gauge

A gauge for measuring the level of LPG inside a horizontally oriented cylindrical storage tank having a diameter within the range of about 24 inches to about 42 inches, said gauge comprising:

• a) a gauge head having a lower portion defining a passage formed on its lower surface and a dial assembly mounting portion formed on its upper surface;
• b) a magnetically coupled indicator dial attached to said dial assembly mounting portion of said gauge head;
• c) a support arm having an longitudinal axis, an upper end connected to said lower portion of said gauge head, a pivot arm attachment portion being located at a first distance from said upper end, and a middle portion extending between said upper end and said float arm attachment portion, said first distance being within the range of about 10.5 inches to about 14 inches;
• said middle portion defining a sideways-securing shaft channel extending between said upper end and said pivot arm attachment portion along said longitudinal axis;
• d) a magnet drive shaft assembly rotatably mounted in said shaft passage and having a magnet holder located at an upper end and a pinion gear located at a distance from said upper end;
• said upper end of said shaft extending beyond said upper end of said support arm and positioning said magnet holder within said passage of said gauge head;
• e) a magnet being secured to said magnet holder of said magnet drive shaft assembly;
• f) a pivot arm being pivotally connected to said pivot arm attachment portion of said support arm, and having a spur gear portion and a float arm attachment portion;
• said spur gear portion including a plurality of gear teeth arranged in an arc around a center point and having a maximum radial distance from said center point;
• said float arm attachment portion having at least one fastening feature for securely connecting a float arm assembly to said pivot arm;
• g) a float arm assembly including a float buoyant in LPG and a float arm including a z-shaped center section, a float arm section and a counterweight section;
• said center section comprising a first, second and third straight sections separated by a first and second 90.degree. angles and being adapted to interfit with the attachment features of said pivot arm;
• said float arm section extending between said center section and said float and further comprising a curved section extending from said float, said curved section constituting, when viewed from the side, a curve having a radius of curvature of at least one inch, and being connected to a first straight section, said first straight section having a length within the range of about 5 inches to about 6 inches and being connected to a first bend, said first bend being connected to a second straight section having a length within the range from about 3 inches to about 21 inches, said second straight section being bounded on a first side by said first bend and bounded on a second side by a second bend, said second bend being connected to said first straight section of said z-shaped center section, said second straight section forming, when viewed from the front, an angle within the range of about 21.degree. to about 0.degree. with respect to a line constituting an extension of said first straight section of the z-shaped center section connected to said second bend;
• said counterweight section extending between said center section and a counterweight and further comprising a third straight section constituting an extension of said third straight section of the z-shaped center section, said third straight section having a length within the range of about 2 inches to about 3 inches, measured from the last 90.degree. bend in said center section, and being connected to a third bend, said third bend being connected to a tail section for attachment of the counterweight, said tail section forming, when viewed from the front, an angle of about 7.degree. with a line constituting
• an extension of said third straight segment,
• and a counterweight attached to said third straight segment;
• wherein said spur gear portion of said pivot arm engages said pinion gear to impart rotational motion to said shaft, said magnet holder and said magnet relative to said support arm and said gauge head upon angular movement of said pivot arm relative to said support arm.

A method of assembling a gauge support assembly for use with a magnetically driven indicating dial assembly and a float arm assembly, said method comprising the steps of:

• a) providing a support arm having a longitudinal axis, an upper end having a generally cylindrical support member projecting therefrom along said longitudinal axis and having a passage formed therethrough along said longitudinal axis, a pivot arm attachment portion being located at a first distance from said upper end, and a middle portion extending between said upper end and said pivot arm attachment portion;
• said middle portion defining a sideways-securing shaft channel extending between said support member and said pivot arm attachment portion along said longitudinal axis;
• said sideways-securing shaft channel having a plurality of securing members formed therealong;
• said pivot arm attachment portion being, when viewed from the front side, front-laterally offset with respect to said longitudinal axis and having a leftmost extent and a rightmost extent defining a lateral width therebetween, and said attachment portion defining an axle passage for receiving a pivot arm pivot axle;
• said axle passage defining a pivot axis for said pivot arm pivot axle;
• said pivot axis being front laterally offset on said attachment portion such that a first distance from the pivot axis to one of said leftmost extent and said rightmost extent is greater than a second distance to the other of said leftmost extent and said rightmost extent such that said pivot axis intersects said longitudinal axis of said support arm;
• b) providing a magnet drive shaft assembly;
• c) inserting at least a portion of said drive shaft assembly downwardly and at an angle with respect to said longitudinal axis through said passage in said support member such that said shaft portion is positioned adjacent to said securing members of said shaft channel but on the opposite side of said securing members from said longitudinal axis,
• d) positioning said shaft portion longitudinally at a desired location with respect to said channel;
• and
• e) securing said shaft portion in said shaft channel by moving it sideways into said shaft channel toward the longitudinal axis until it is secured by said securing members.