Overfill protection device

• US 6,138,709 A
• Filed: 01/27/1998
• Issued: 10/31/2000
• Est. Priority Date: 01/27/1998
• Status: Expired due to Term

• Current Assignee: Home, William
• Original Assignee: Home, William
• Inventors: Home, William
• Primary Examiner(s): Walton, George L.
• Application Number:
  US09/013,887
• Time in Patent Office: 1,008 Days
• Field of Search: 137/430, 137/413, 137/446, 137/442, 137/443, 137/444, 141/198, 141/18, 251/900
• US Class Current: 137/413
• CPC Class Codes: F16K 1/303 with a valve member, e.g. stem or shaft, passing through the seat
• CPC Class Codes: F16K 1/307 Additional means used in combination with the main valve
• CPC Class Codes: F16K 31/34 acting on pilot valve controlling the cut-off apparatus
• CPC Class Codes: F17C 2250/0413 with floats
• CPC Class Codes: Y10S 251/90 Valves with o-rings
• CPC Class Codes: Y10T 137/7371 Fluid pressure
• CPC Class Codes: Y10T 137/7472 Vertical inlet riser
• CPC Class Codes: Y10T 137/7478 With interposed cam, gear or threaded connection

Abstract

A overfill protection device includes a first tubular member, a cylindrical piston slidably fitted within the first tubular member, a spring arranged within the first tubular member and fitted over an intermediate portion of the piston, a first and second O-rings fitted in the first and second neck portions of the piston respectively, a second tubular member having an upper portion having a cylindrical recess open at a top and engaged with the first tubular member, a plug arranged within the second tubular member and located under the piston, a float rod having a cam plate at an upper end thereof, and a float fixedly connected with a lower end of the float rod, whereby no gas will be allowed to flow through the overfill protection device when the pressure within the gas tank exceeds a predetermined level.

Claims

1. A overfill protection device comprising:

a first tubular member having an upper portion formed with a first axial through hole, an intermediate portion having a second axial through hole with a larger diameter than said first axial through hole and four radial through holes, a lower portion having a third axial through hole with a larger diameter than said second axial through hole and external threads, and an annular groove formed between said second and third axial through holes;

a cylindrical piston slidably fitted within said first tubular member and having an upper portion, dimensioned to fit into said first axial through hole, an intermediate portion having a larger diameter than said upper portion of said cylindrical pistion and dimensioned to fit into said second axial through, a lower portion having a larger diameter than said intermediate portion of said cylindrical piston and dimensioned to fit into said third axial through hole, a first neck portion between said upper and intermediate portions of said cylindrical piston, a second neck portion on said lower portion of said cylindrical piston, and a circular recess at a bottom of said lower portion of said cylindrical piston, said upper portion of said piston being formed with a through hole, said first neck portion having an axial through hole having same diameter as a lower end of said through hole of said upper portion of said piston, an axial through hole being formed in said intermediate and lower portions of said piston and having an upper and lower ends communicated with said axial through hole of said first neck portion and said circular recess;

a spring arranged within said third axial through hole of said lower portion of said first tubular member and fitted over said intermediate portion of said piston, said spring having an upper and lower ends respectively bearing against said annular groove and said lower portion of said first tubular member;

a first and second O-rings fitted in said first and second neck portions of said piston respectively;

a second tubular member having an upper portion having a cylindrical recess open at a top and provided with internal threads engageable with said external threads of said first tubular member, an intermediate portion having an axial through hole with a smaller diameter than said third axial through hole of said first tubular member, and a lower portion having an axial through hole with a smaller diameter than said axial through hole of said intermediate portion, said lower end of the second tubular member being divided by a diametrical slot;

a plug having an upper portion formed with a neck portion fitted with a O-ring and a lower portion having a smaller diameter than said axial through hole of said second tubular member and formed with a conical lower end, said plug being arranged within said second tubular member and located under said piston;

a float rod having a cam plate at an upper end thereof, said cam plate being fitted into said slot of said second tubular member and pivotally connected thereto by a spindle extending through said second tubular member and said cam plate, said cam plate being contoured to form a lobe, a convex edge and a concave edge; and

a float fixedly connected with a lower end of said float rod.

2. The overfill protection device as claimed in claim 1, wherein two of said radial through holes are aligned with another two of said radial through holes and two axes through the radial through holes intersect at an angle of 40-50 degrees.

3. The overfill protection device as claimed in claim 1, wherein said conical through hole of said piston has an upper diameter and a lower diameter which are in a ratio of three to one.

4. The over fill protection device as claimed in claim 1, wherein said first tubular member is formed with a radial perforation extending through said first tubular member to communicate with said annular groove.