Patent writing and filing
Patent searching and evaluation
Patent infringement opinions
Patent litigation
Advice for "designing around" patented products
Trademark filing
Trademark searching


Don Ersler helped me complete my first aircraft patent.  His diverse background including multiple engineering degrees gives him the ability to quickly understand and evaluate complex designs and concepts.  The patent I attained with his help has proven to be most valuable and it possesses the depth and breadth to stand in our industry with great strength.  Firms such as Perkins Coie and other major players in our industry (i.e. Boeing) have acknowledged and even cited it in their own efforts to patent other designs near our space and expertise.  I have appreciated the solid and efficient work that Don achieved and I will engage him again for another set of patents on my next generation design projects.  I highly recommend Don especially for any technical design patent needs.

Brian H. Morgan

Inventor & Founder

Morgan Engineering LLC


Until we engaged Don Ersler as patent counsel our experience with several other firms had been, in the main, disappointing. His expertise in the fields of mechanical and electrical engineering coupled with his quick grasp of complicated issues resulted in our obtaining three essential patents in a very short period of time at a cost that was more than reasonable. His ability to communicate with the examiners at the patent office certainly has been of a real benefit to Altapure. I would recommend Atty. Ersler without reservation.

Carl L. Ricciardi
President and General Counsel
Altapure, LLC


I have recommended you to a few of my close friends. I like the way you work. Honesty and trust is not easy to come by lately.

Dorge O. Huang


Mr Ersler has represented me since the beginning of 2014 to secure a utility patent through the USPTO. The Nonprovisional Patent Application was filed in February of 2014.  The Notice of Allowance for the patent was provided from the USPTO in January of 2015,


During his engagement Mr Ersler has prepared the application, responded to a restriction requirement, amended claims after a First Office Action, prepared and provided new independent claims, timely completed all necessary filings and secured the notice of allowance.  He has, in a kind, steady and methodic fashion, completed the necessary patent search, worked with the draftsman to secure all drawings, provided progress reports, completed all filings and was always available to answer and discuss the project by phone.

It should be noted that his charges are reasonable, he completes all necessary tasks on time, he is straight forward with you and works with you toward the achievement of your issuance goal.


This is my first experience with Mr Ersler and I recommend his services without reservation.  Please note that I am a practicing attorney for the last 37 years.

William J. Parker, J.D.


Mr. Donald Ersler guided me through what I thought was going to be a very pain-staking process. Instead it was efficient, timely, educational and painless. From the beginning of the process to the end Mr. Ersler kept me constantly and instantaneously informed with every action taken. I was informed and educated by him every step of the way and was shocked at the speed in which he operates. Every time I had a question Mr. Ersler himself answered my call and did not hesitate to take the time to answer it. My experience working with Mr. Ersler was a refreshing and pleasant one and would recommend his services to anyone. If you are in need of a true professional, I would highly recommend that you stop here!

Bernard Jock


Attorney Donald Ersler has helped me with numerous intellectual property issues over the years. I have found his advice to be sound, his patient and thorough probing to be responsible, and his prices to be very reasonable. I recommend him without reservation to anyone needing help with patents, trademarks, or copyright issues.

Dr. Joel Orr
Orr Associates International


If you are looking for a top-notch patent attorney, look no further than Mr. Donald Ersler. With over 17 years of legal experience, Mr. Ersler practices law with poise, professionalism and a prudence that is second to none. His keen ability to navigate the tumultuous waters of the patent process, from the initial search to any subsequent defense, leaves his clients feeling assured that they are dealing with a prompt and highly productive professional. Clients will undoubtedly appreciate his upfront flat fees that allow for easier budgeting and long-range planning. He is responsible and reliable, ethical and enthusiastic, and client-centered and community-minded. His interpersonal communication style works to ease any anxiety his may feel at the onset of the patent process. I will continue to work with and promote the highly reviewed and regarded, Donald J. Ersler, as the top patent attorney in Greater Milwaukee.

Jennifer Wells


Attorney Ersler is by far the best patent attorney we've worked with. His expertise shines through in every thing he's done for us. Why have we placed such an enormous amount of trust in his abilities over the years? Because Attorney Ersler has handled all of our patent work with great care and extraordinary attention to detail. He is very skilled in his art and easy to work with.

Matt Collins


I offer this letter of recommendation on behalf of patent attorney Don Ersler. I have trusted his judgment for patent applications and patent infringement matters. Unlike other patent attorneys, Don encourages me to think of alternative embodiments for my invention when filing a patent application. When I have need of infringement analysis for an issued patent, Don provides me with a thorough analysis of the patent and also provides alternative design strategies for avoiding infringement of the issued patent. All this expertise done at a reasonable cost and within a reasonable time period.

Karl B. Schmidt
Pivot Putter, Inc.

Contact information concerning the above clients are available upon request.


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