U.S. Padlock Patents Book

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Padlock Patents Book - Revision 8

Searchable Data Items...
Patent Number
Issue Date
Inventor Name
Assigned to Name
Patent Type Code

Searchable Patent Type Codes ... Entered as (type code)
chain        Chain Locks, including Cable Locks
comb        Combination
design      Design
fire           Patent lost in 1836 fire
ind           Indicator/Counter, including recording locks
lever         Lever
pk            Push Key
pt             Pin Tumbler
ptpk         Pin Tumbler Push Key
scandi      Scandinavian
screw       Screw
seal          Seal
trick         Trick
wafer        Wafer Tumbler, including Grip Tumbler, Disc Cylinder
warded     Warded
misc         The patent does not fit into a major (type code)
research   This patent requires further research
noimage   We have not found a padlock for this patent

Active Links...
Patent Number Links to Google PDF


There are over 2,000 patents listed in the book.

Not all patents were manufactured.

There are a few patents that were not found in the USPTO database. We have assigned patent number 000000 to these patents.

Some manufacturers used their door patent mechanisms to cover their padlocks. For instance: A cylinder pin tumbler mechanism is used to cover a padlock pin tumbler. This we believe to be a legitimate use of the patent.

There are a few cases where the patent used to cover a padlock is erroneous. We can only imagine why this was done.

If the Assigned to Name does not clearly represent the manufacturer or the manufacturer is not correct, we will add a note as to who we believe the manufacturer was.

When possible, an image of the actual padlock is added.

Not all padlocks covered by a patent bear a patent number or patent date, we will do our best to find an image of the actual padlock.

There are numerous patents that are an improvement of a previous patent. In most cases this patent number or date never appears on a lock, but the improvement is employed in the locks produced. The only way to identify these locks is to open each lock and examine them. This is something we have not done. We have added an image of a lock that we believe contains this improvement.

We have included a list of padlock patents that were lost in the USPTO fire of 1836. The information known is limited. We will add to this list as they are discovered.

Search Tips

To find all Push Key patents search for (pk).

To find all patents that do not have an image search for (noimage).

To find all Push Key patents that do not have an image you will have to do 2 searches, this is because a patent can be assigned more than 1 type code.

        Search #1: Search for (pk)(noimage). This will return most of the Push Key patents that do not have an image.

        Search #2: Search for (noimage)(pk). This will return very few if any Push Key patents that do not have an image.



Patent Summary

Patent Detail


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