Patexia Contest


This contest is closed.
Runner Up

Pratap Vardhan



We request previously undiscovered prior art (If you are new, see: patent and prior art basics and tips for Patexia's prior art contests) including patents and non-patent literature (English and foreign language) that can help invalidate claim 1 of US patent 7,900,867 (‘867) - Personal propulsion Device. 

The patent describes a wearable water “jetpack” propulsed by pressurized water pumped from an auxiliary unit. The best qualifying submission is guaranteed to receive the prize. The following questions will help you understand what we are looking for in this study.

Jetpack Illustration


The reference(s) should clearly satisfy the following:

  • Must be published before March 22, 2004 (clearly dated).
  • Describes a water jetpack that operates similar to this product
  • The water jetpack uses a pump system with a source of water
  • The pump system is connected to the jetpack through a tube or hose.

Contest entries can alternatively include a combination of several references from which the above system is obvious.

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1Is the reference published before March 22, 2004 (and clearly dated)? 0
2Does the reference describe a water jetpack that operates similar to this product? 0
3Does the reference describe a water jetpack that uses a pump system with a source of water? 0
4Does the reference describe a pump system that is connected to a jetpack through a tube or hose? 0

Additional Notes

Submission Notes:

  • Submission deadline is December 14, 2012
  • All work must be prepared by a single researcher
  • If you are referred, the referral prize ($500) will be paid out of the total prize pool of $1000.
  • Maximum of one entry per person allowed
  • Entries must be in English
  • In case you are submitting foreign references, please provide a translation of key sections
  • If your reference has already been submitted by another researcher before you or is among the known references, it will not be considered for the contest.
  • Please use “Ask a Question” to post general questions or feedback about the contest to the community.
  • For specific questions, you can contact us directly by email at
  • All submissions are subject to Patexia's contest legal terms. Failure to follow these rules may lead to disqualification from the contest

Acceptance Criteria:

  • If the submitted reference(s) clearly satisfies all the questions, the researcher will be awarded full prize (102 rejection)
  • If the submitted reference(s) at least satisfies questions 1 and 2, the researcher will be awarded 20% of the prize (103 rejection)

Known References:

The following US patents are known prior art related to patent ‘867. Please do not resubmit them.

  • 1,833,354
  • 2,461,347
  • 2,509,603
  • 2,920,841
  • 3,021,095
  • 3,023,980
  • 3,149,798
  • 3,176,984
  • 3,243,144
  • 3,245,637
  • 3,277,858
  • 3,381,917
  • 3,443,775
  • 3,747,987
  • 3,503,574
  • 3,570,785
  • 3,586,263
  • 3,614,024
  • 3,700,172
  • 4,040,577
  • 7,348,976
  • 4,417,706
  • 4,541,357
  • 4,738,212
  • 5,679,035
  • 5,779,188
  • 6,488,232