Masterfilter Ltd is the company that owns this patent.

The patent no is PN 829158 GB I believe payments were suspended.

Has the application been abandoned, or is it still pending.

  • If you could provide a link to the patent it would make it easier to answer the question. For instance the patent number cited is not from Masterfilter patents.google.com/patent/GB829158A/en?oq=829158+GB
    – Eric S
    Jun 13, 2020 at 15:23
  • Is this the patent in question? 829158 Improved vehicle front suspension GB - 24.02.1960 Applicant GEN MOTORS CORP
    – George White
    Jun 13, 2020 at 19:55

1 Answer 1


Espacent shows this patent was filed in 1957 (the priority date) so it has in fact expired. Granted patent are only valid for 20 years from the original filing date. (in this case that was in the USA 12/02/1957)

After publication the disclosed product/prodcution method can be used as a basis for a new patent by adding a new inventive step that improves some deficiency in the original patent.The added inventive step has to be novel and must not be obvious. At filing stage the patent is given an "A" suffix and when granted a "B" suffix

In this case there is only an spec "A" (i.e.: GB829158A) patent shown. This normally indicates that it was never granted in the first place but fell during the search examination procedure.

You may find this link helpfull

[how to read a patent specification][1]


  • The problem is the patent number supplied can't possibly be the patent they are worried about since it is from a different company. Also US patents from prior to about 1995 expired 17 years from issue not 20 years from filing. Also, your attempt at a link doesn't work.
    – Eric S
    Jun 15, 2020 at 22:49
  • @EricShain - FYI - The U.S. term was changed in the Uruguay Round of TRIPS to conform with the "rest of the world". I did not readily find the term rules for the UK in the 1950's.
    – George White
    Jun 16, 2020 at 2:09
  • And a note to @logikman - welcome to Ask Patents. Like all stack exchange sites, our style is to not include signatures at the end of posts.
    – George White
    Jun 16, 2020 at 2:12
  • 1
    @logikman Actually, the "A" kind code for publication of GB patents in the 1950s indicated a granted patent. This link has a thorough summary of the kind codes of different countries' patent offices through history. Nov 23, 2020 at 16:18
  • Also, your link didn't work. Please try to fix that.
    – Eric S
    Mar 12, 2021 at 14:59

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