| # | Country | Total Patents | |
|---|---|---|---|
| #1 | United Kingdom | 7 | |
| #2 | Denmark | 3 | |
| #3 | France | 3 | |
| #4 | Australia | 2 | |
| #5 | Belgium | 2 | |
| #6 | Canada | 2 | |
| #7 | EPO (European Patent Office) | 2 | |
| #8 | Italy | 2 | |
| #9 | United States | 2 | |
| #10 | Brazil | 1 | |
| #11 | Switzerland | 1 | |
| #12 | Cyprus | 1 | |
| #13 | Germany | 1 | |
| #14 | Spain | 1 | |
| #15 | Ireland | 1 | |
| #16 | Malaysia | 1 | |
| #17 | Norway | 1 | |
| #18 | Singapore | 1 | |
| #19 | South Africa | 1 |
| # | Industry | |
|---|---|---|
| #1 | Civil engineering | |
| #2 | Materials and metallurgy | |
| #3 | Machines | |
| #4 | Mechanical elements |
| # | Technology | |
|---|---|---|
| #1 | Foundations and excavations | |
| #2 | Foundry moulding | |
| #3 | Sewers | |
| #4 | Venting or aerating devices | |
| #5 | Unspecified technologies | |
| #6 | Shaping clay |
| # | Name | Total Patents |
|---|---|---|
| #1 | Harvey David Martin | 8 |
| #2 | Bowley Clive | 4 |
| #3 | Elkington Vivian | 2 |
| #4 | Holdstock Herbert Jack | 2 |
| #5 | Pollock Thomas | 1 |
| #6 | Vivian Elkington | 1 |
| #7 | Clivie Bowley | 1 |
| #8 | Harvey David M | 1 |
| #9 | Hawkins Brian Walter | 1 |
| #10 | Harvey D M | 1 |
| Publication | Filing date | Title |
|---|---|---|
| GB8509794D0 | Manhole cover frames | |
| GB8325048D0 | Covers and frames | |
| IE812272L | Manhole cover frame production | |
| CY1267A | Manufacturing manhole cover frames | |
| GB2066335A | Manhole covers | |
| GB1192321A | Improvements relating to Manhole and like Covers and Frames | |
| GB1186860A | Improvements relating to manhole and like covers and frames | |
| GB1144636A | Improvements relating to gratings for openings in roadways and floors | |
| US2877696A | Manhole covers and frames | |
| US969803A | Stop-valve. | |
| CA572282A | Manhole covers and frames |