| # | Country | Total Patents | |
|---|---|---|---|
| #1 | United States | 21 | |
| #2 | Canada | 4 |
| # | Industry | |
|---|---|---|
| #1 | Mechanical elements | |
| #2 | Machines | |
| #3 | Packaging and shipping | |
| #4 | Engines, pumps and turbines | |
| #5 | Civil engineering |
| # | Technology | |
|---|---|---|
| #1 | Venting or aerating devices | |
| #2 | Unspecified technologies | |
| #3 | Pistons and sealings | |
| #4 | Pipes | |
| #5 | Pumps | |
| #6 | Winches | |
| #7 | Earth drilling | |
| #8 | Elevators and escalators | |
| #9 | Unspecified technologies |
| # | Name | Total Patents |
|---|---|---|
| #1 | Stillwagon Crawford K | 25 |
| Publication | Filing date | Title |
|---|---|---|
| US3172424A | Disc type check valve | |
| US3129920A | Conduit connection and valve | |
| US3127904A | Disc valve | |
| US3043557A | Disc valve having periphery sealing ribs | |
| US3024802A | Disc valve | |
| US2994342A | Valve | |
| US3100500A | Disc valve with removable seat and unitary stem and disc, and seat and stem bushing unit therefor | |
| US2942841A | Slide valve | |
| US2856952A | Valve | |
| US2936778A | Butterfly valve | |
| US2912218A | Valve | |
| US2740423A | Disc valve | |
| US2656229A | Piston and piston and rod combination | |
| US2679441A | Piston | |
| US2597829A | Piston | |
| US2288116A | Snatch block | |
| US2318112A | Union | |
| US2232890A | Derrick elevator | |
| US2235302A | Snatch block | |
| US2216577A | Combination piston and rod |