The switch on traditional ratchet wrenches makes it hard to remember what direction the tool will apply torque to a bolt or nut. If the Little Ratchets create a design that makes the switch a simple button, the initial torque applied by the user can instantly set the wrench in the correct direction. The button that will reset the mechanical system will also work better in tight spaces, and will not accidentally switch positions by miscellaneous objects. This will make the use of ratchet wrenches universal for all levels of experience. If the design is feasible it could replace the easy release wrench currently on the market. The easy release feature will still be available because the new design must resemble current wrenches, and the comparison between new and old will appeal to consumers. Easy to follow instruction manuals with images will be provided to all customers. The Self-Directing Ratchet will revolutionize the tool industry and save countless mistakes across the world.
Proof of Concept
The proof of concept for the Self-Directing Ratchet is a way to experimentally show that the concept depicted in previous tasks will actually work. Team 12B has constructed the PoC out of relatively inexpensive materials, and it will provide a range of variabilities that can be adjusted prior to manufacturing. The proof of concept model has been drawn up on solidworks and further analysis can be done to test fatigue risks. Risk of failure will also be tested in the real model that has been built to prove this concept.
Items needed for this PoC consist of a plastic six sided die with a ninety-degree V-cut into one side, a T-bar secured to the pawl, and two wooden plates that hold everything together. The wooden plates hold the die and the wrench in an orientation that ensures the user input does not assist with the alignment.
The purpose of the Self-Directing Ratchet is to make the use of ratchet wrenches as easy as possible. The wrench itself has come a long way, but Team 12 is determined to take it one step further. Ratchet wrenches on the market today either have a switch or a rotating nob that is moved, by the user, to change the engagement of direction. Continuously flipping the switch one direction, or rotating the nob in the opposite direction, leads to the wrench setting being forgotten by the user. This may not seem like an issue to the average person, but after speaking with professionals in the industry, there was an indication of a common problem. Team 12 has designed the Self-Directing Ratchet with a button, rather than switch or nob, which is simply pressed by the user. After the press, the wrench will engage itself in the direction that the user initially applies torque. With this design, there is no need to remember which direction the wrench is set to, or which way the nob needs to be turned, and no more frustration.
Figure 1 shows a drawing created with SolidWorks of the prototype design. Being in the early stages of development, this prototype may not be as esthetically appealing as the wrenches sold on the market today, but it looks much better than the Proof of Concept (POC) which was handcrafted out of wood. This prototype will be made with higher tolerances and a 100% use success rate is to be expected. The POC had some flaws that this design will correct.
Every aspect of the design has been made with the understanding that manufacturing costs of this product must be low. The modifications have been made to a Craftsman’s wrench so replication of most parts (such as anvil and pawl) will be identical to the existing design. The directional control unit (the switch) from the wrench was replaced with a small, square button, depicted in Figure 1. Only slight modifications were made to the pawl. The button interacts with the pawl so that it twists to a neutral position, and once the user applies the initial torque, it engages the anvil in the desired direction.
This product will be useful to industry professionals as well as the average person. The user simply needs to know that the counter-clockwise direction loosens, and the clockwise direction tightens. The Self-Directing Ratchet is going to revolutionize the auto, marine, and cycling industries. Those who work with ratchet wrenches on a daily basis will be attracted to this efficient design and will wonder why it hasn’t always been this way.
Fabrication: The Auto-Locking Ratchet Wrench was fabricated using scrap metal and three machines: a manual mill, a CNC mill, and a manual lathe. The manual mill was used to create features on the main body of the ratchet. The CNC mill was used to produce the button, the main body, and the main body cover. Finally, the manual lathe was used to fabricate the anvil button and the ratchet handle.
The assembly of the Auto-Locking Ratchet Wrench is simple. The following steps describe the assembly of the ratchet. First, the snap ring goes on the groove for the button. Then, the t-bar is placed into the pawl with the “t” on top and the “t” arms oriented from left to right, with respect to the ratchet. The t-bar is then adhered with epoxy. The anvil is placed into the main body. The pawl is then locked into either the counterclockwise or clockwise position with the anvil. The main body is rotated up, with the handle hole being on top. The ball bearing and spring are placed in the handle hole, respectively. The handle is screwed on hand tight, lock tight can be used. The anvil button and pawl button assembly are then placed into the main body cover with the anvil button in the square hole and the pawl button in the circular hole. A spring is placed in the hole on the bottom side of the pawl button. While keeping the main body cover in a fixed position, the main body assembly is placed on the main body cover assembly. Pressing the main body cover tightly to the main body, the wrench is flipped 180 degrees. The three main body cover screws are installed. Check for proper functionality of the Auto-Locking Ratchet Wrench. Finally, the assembly is complete.
Testing and Results
The Auto-Locking Ratchet Wrench (ALRW) is designed to solve the problems posed by current ratchet wrenches. Mainly, the switch mechanism on some ratchet wrenches create problems in unreliability, time consumption, and lack in user ease-of-use. The switch is easily moved from outside objects, without the user’s consent, and the user has to remember to change the switch direction before using. The ALRW solves these problems successfully, which, in turn, makes it easier for the user to use. Proof of problem solutions are seen in the product tests and survey done on the ALRW.
The ALRW went through a series of tests to prove its durability and functionality. Three tests were done in order to display the durability, operations, and torque strength of the product. First, a drop test was used on the ALRW to display success in the product’s strength. Second, was to test the functionality of the innovative design. Third, a torque test was performed to prove the strength in the handle and main body.
The drop test is in conjunction with the ASME B107.110 standard which states that socket wrenches, handles, and attachments must withstand a drop from six feet above the ground. If the ALRW does not show any signs of broken parts and obstruction to its overall functionality, the product passes the test. This test is important because it proves the product will not fail under user wear and impact. The ALRW passed the drop test a total of 10 times without causing any damage to the main body or interior components.
The functionality test resembles the test performed on the proof of concept. The operation was tested 250 times, with random directions selected, to ensure the product works in rotating both clockwise and counterclockwise from the push of the button. The test is successful if the wrench achieves a 100% success rate in the 250 trials. The wrench passes this test and successfully proves its functionality and thorough design synthesis. There has been an interference discovered with some socket attachments. This was not discovered until after the test. There is a displacement in the anvil which will cause the pawl to slip and some sockets put the anvil in that location. Fixing this is done by eliminating the easy-on function which was added to the wrench during manufacturing. Since this is not the innovation of the design it does not change any invention in the product.
The torque test is also congruent with the ASME standard which states that the handle and wrench must be able to withstand 150ft•lbs . Prior to innovation day a total of 100ft•lbs was exerted on both. A precision tool was used on the ratchet to prove its sturdy torque application. The team decided to not apply too much torque to the ratchet in the test to protect the product before public display. After innovation day 150ft•lbs were applied to the wrench to display its torque abilities and overall strength. This torque was applied in both directions a total of 4 times. If the product did not break under such applied moments, then the ratchet passes the test. The ALRW successfully held up under the 150ft•lbs of torque and passed the torque test. No permanent deformation was observed. The ALRW shows substantial ability to withstand torque that is much higher than will be observed in everyday use. THE Auto-Locking Ratchet Wrench achieves all applicable standards laid out by the ASME B107.110 which was a goal of the team.
During innovation day a survey was provided for those who tested the product in order to gauge how the public would react to this product on the market. A total of 28 surveys were taken by persons attending innovation day. The first survey question asked about the user liked the ALRW. Out of the surveys collected, we achieved a 91% overall. The second question asked about the ease of use for the ALRW and also achieved a 91% overall score. Lastly, product testers were asked how they liked the ALRW and the team is pleased to report that we achieved a whopping 96%.
Based on the positive feedback received during innovation day and these three successful tests on the product, the ALRW meets its requirements in durability, operations, strength, and user satisfaction. With the ALRW passing each test, the wrench is seen to withstand impacts, torque, and use; these results express that the ALRW solves the problems it was originally designed to solve. The Auto-Locking Ratchet Wrench set out to eliminate all problems posed by current ratchet wrench designs by eliminating old methods and creating a simple, easy to use button mechanism. The final prototype far exceeds all expectations set forth by the team and by users of the product.
Meet the Team
Cameron Gish was born and raised in Sacramento, CA. He is a senior in the undergraduate mechanical engineering program and business and administration program at the University of Nevada, Reno. He is a problem-solving oriented person with a strong interest in pursuing a career as a mechanical engineer. Cameron has been fortunate enough to obtain two seasonal internships with high quality firms by persevering through his studies. Throughout the course of his internships and his college career he learned first hand of what traits it takes to create a strong team and successful engineer. Cameron plans to work at Kitchell as a mechanical engineer when he graduates, but still is keeping an open mind for other opportunities.
Tanya Flint is a senior studying Mechanical Engineering and concurrently working towards her Masters in Business Administration at the University of Nevada, Reno. She is very involved on campus and has been involved in various organizations from being a member of the Delta Gamma sorority to being in the American Society of Civil Engineers and even a Concrete Canoe Team member. Tanya has held many leadership positions in her various organizations, including the title of Panhellenic President, where she oversaw all of the sororities on campus, to her current title of ASCE President where she has helped plan conferences and networked with many local professional engineers. She enjoys being involved and being a leader on campus. Tanya is from Sacramento, California and enjoys being so close to home and Lake Tahoe at the same time. Tanya is currently working towards acceptance in the MBA program at the University, and if accepted, will stay in school a year to complete her Masters.
Quaid Berry is a senior in the undergraduate mechanical engineering program at the University of Nevada, Reno. He held an internship for a year in a half which has given him experience in manufacturing, heat transfer, and engines testing. His six years of customer service have made him very comfortable with public speaking, and engineering communications prepared him for technical presentations. He currently does research at DRI which is influential in future regulations of biofuels. Quaid’s experience has given him intuition, understanding, and creativity in the physical world which will be helpful in reaching the group’s goals. Quaid is a local who learned how to fly small aircraft at the Reno/Tahoe airport, and received his Private Pilot’s Licence in 2009. Flying is his passion and he wants to work towards an Instrument Rating after graduation. He will consider this a form of specialized education, but to achieve this goal he will have to be established in his first career as an engineer in training.
Tyler Burger was born in Long Beach, CA. and moved to Reno, NV. in 2005. He is a senior in the undergraduate mechanical engineering program at the University of Nevada, Reno. In the 2014 school year he was recognized on the Mechanical Engineering Dean’s List.Through practical work experience he has shown proficiency with accurately interpreting technical writing as well as performing complex testing procedures on a variety of electro-mechanical systems. He is currently employed with two separate employers working as a Sales Associate and Bike Technician at Sierra Cyclesmith as well as a New Car Build Technician for the Nevada Highway Patrol. After graduation from the University of Nevada, Reno, Tyler would like to pursue a career in suspension design and optimization for mountain bikes.
Kristen Shutt is a senior studying Mechanical Engineering and Art at the University of Nevada, Reno. Kristen is from Dana Point, CA. She embraces her studies outside of the classroom–from seasons of travelling across the U.S. for an Oak Ridge National Laboratory internship to humbly working at local ski resort, Squaw Valley. Kristen eagerly resolves issues, presents herself, and listens to others with an open mind. These abilities allow her to strengthen her leadership, problem solving, and designing skills in her schooling. All these qualities will enhance and compliment the senior team’s capabilities, and, one day, help the community. Kristen plans on working as an automotive designer, firmly applying her aerodynamic, fluid dynamic, and design skills in the field. Her passions in the automotive field will one day lead her to off-road competition.
Team 12 thanks Tara Radniecki, Tony Berendsen, Nicholas Maus, Nicholas Zerbel, Dr. Ingole, Patrick Stampfli, and Kai Carl for all the help received toward the Auto-Locking Ratchet Wrench project.