US 2013/0078073

It is a gantry for a 3d printer. It uses what is commonly referred to as an H-Bot configuration. It was filed Sep.23, 2011.

A simple Google search with the term H-Bot from 2009-2010 will reveal sites, videos and other info for the -exact- same mechanical setup. For example here(dated Oct 29, 2009):

Rockwell automation catalogue

The H-bot gantry is essentially what is called a Cartesian robot, and Cartesian robots are a building block of many robots including but not limited to CNC machines, laser cutters and similar. The only difference here is that a known component is placed into a 3d printer instead of a CNC machine or other similar robot.

I would love to make a call for prior art, but I would like to hear thoughts from people who know more about the patent system first.

Claim 1 of the application:

  1. A gantry assembly comprising:

    a first bearing shaft extending along a first axis;

    a carriage slidably engaged with the first bearing shaft;

    a second bearing shaft operably supported by the carriage, the second bearing shaft extending along a second axis that defines a plane with the first axis;

    a tool-head mount slidably engaged with the second bearing shaft;

    a drive belt secured to the tool-head mount;

    a first motor having a first drive shaft engaged with the drive belt; and

    a second motor having a second drive shaft engaged with the drive belt, wherein the first motor and the second motor are configured to operate independently to rotate the drive belt in manners that move the carriage along the first bearing shaft and that move the head-tool mount along the second bearing shaft based on relative rotational directions and rotational rates between the first drive shaft and the second drive shaft, so as to allow movement of the tool-head mount to any coordinate location within the plane, wherein the gantry assembly is configured to reduce pivoting of the carriage in the plane.

1 Answer 1


I'm not a lawyer but I know a bit about 3D printing (this isn't legal advice :) )

It's still a patent application so it's not approved yet and we don't know whether any of the claims will be accepted.

You're right that the H-bit you show in that catalogue looks a lot like it, and given it was being used on a CNC which is "subtractive manufacturing", I doubt that using it in a 3D printer which is "additive manufacturing" can really be considered novel or unobvious but who knows.

What's a little surprising is that this is Stratasys which is a major player in 3D printing, who I'm sure would know about the H-configuration, yet their prior art references is a little on the short side and seems to not mention any existing such configurations.

You're allowed to submit 3 pieces of prior art for free against that application (here are some easy instructions: I want to make a difference - how can I submit prior art to the Patent Office?). I'd say pick the best 3 that a USPTO examiner can understand and just do it.

  • Thank you. The patent intentionally avoids calling it an H-bot, a well established term among 'those skilled in the art' as called in the patent text, thus making the search for prior art nigh impossible, that's what I'm afraid of here. I will see about the best examples I can find :) Nov 27, 2013 at 5:48
  • Yeah - again, I'm not a lawyer but I believe these guys are supposed to sign a declaration that they are not aware of any other prior art that may be related and I find that a little misleading from one of the top 3D printing companies in the world. Do send those examples in/call for prior art.
    – aed
    Nov 27, 2013 at 6:59
  • The IDS form filed by the applicant listing relevant publications it knows about has 17 US patents, another 17 UA published patent applications, 1 PCT application and 2 non-patent literature references. I don't have a view on the merits of the application but it is incorrect to say the applicant claims to be unaware of anything similar previously done. At this point (11/27/13) the application has had a non-final rejection. If you are going to send in 3 items they will need to be something beyond what is already on the record in the case to be of much impact.
    – George White
    Nov 27, 2013 at 17:39
  • Thank you for your reply Mr. White. Yes, it does list several references of prior art but the usage of the system in those is very different than in the actual application (such as a drawing board), while there are machines out there which are much more similar (such as CNC machines). Can you please explain what the non-final rejection means? Nov 27, 2013 at 22:57
  • From what I can tell this patent has received a "Final Rejection Mailed" status two days ago. I don't know if the title of the question should be updated or something done with this. I'm completely new here so sorry about being uninformed. Dec 14, 2013 at 15:28

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