More than half a century has passed since Bettcher’s electric trimmer debuted, but engineers continue the pursuit of design improvement.
Keith Moffitt demonstrates a power knife equipped with a vacuum-removal element to salvage small quantities of breast meat from chicken carcasses. Originally designed for removal of cow’s spines, the knife was adapted for harvesting meat from smaller animals.
A common gripe among OEMs is a lack of insight into how their machines are used. It’s the downside of outsourcing: An engineer can design equipment to perform a specified task, but without an understanding of how the equipment is used, design improvements aren’t going to be made.
That was never a problem for Louis Bettcher and the company he founded. Bettcher’s machine shop was in the heart of Cleveland’s meatpacking district, where Bettcher had a front-row seat to its practices. Believing the proper tool could debone much of the meat being thrown away, he machined a handheld power knife. His design-a ring-shaped blade that rotated at high speed-quickly won him entrance to the plants, where he observed how workers used the knife. That began a cycle of refinements and improvements that continues to this day. By the time Bettcher retired as chairman in 1987, a team of mechanical engineers and toolmakers was dedicated to continuous improvements and prototyping, based on end-user feedback and the team’s firsthand observations.
Bettcher’s retirement coincided with the addition of Jeffrey A. Whited to the R&D staff. Whited joined Bettcher as a special projects engineer, working with existing equipment and later developing new equipment for the company’s foodservice line. He was named research & development manager in 1996. He began his career as an assembler of packaging machinery and later worked as a design supervisor of packaging equipment at the Aluminum Company of America. Whited is a graduate of the University of Akron with a BS in mechanical engineering. He is named as the inventor on 26 US patents assigned to Bettcher Industries.
FE: Did the firm’s founder mentor you?
Jeffrey A. Whited, research & development manager, Bettcher Industries Inc., Vermilion, OH. Source: Bettcher Industries.
Whited: Another engineer worked directly with Lou when I joined. My first responsibilities involved tools for foodservice. The first patent application listing me as the inventor was filed in 1994. It was for a rotary electric-powered knife with a slicing gauge for cutting gyro meat. FE: What initiated that project?
Whited: Most gyro-shop owners are experts with a carving knife, and they control yield by doing the sandwich slicing themselves. The meat cooks from the outside, and it’s very important that the cuts aren’t too deep, or you’ll cut into uncooked or undercooked meat. Some shop owners were improvising with our trimmers, and a UK company had developed a round disk unit so that nonexperts could do the slicing, but neither approach was very easy to use.
We had an in at some restaurants in Chicago, where the gyro cones also were manufactured, so I went there and spent a few weeks in gyro shops, watching the process and figuring out how we could design a tool that would be easier to use. We came up with a gauge to control the depth of the cut, a narrower blade profile to make it easier to trim the meat at the bottom of the cone, then added a splatter shield and a chute where the slices dropped down. We put the motor into the trimmer handle, made some additional tweaks and ended up with an affordable system that was easy to use and let anyone do the slicing.FE: How has the trimmer product changed during your time?
Whited: A modular version was developed around 1987. It allowed users to change handles to fit their hands and switch between right- and left-handed use. A rubber handgrip was added to reduce vibration and provide insulation from the cold aluminum handle. A micro-brake strap was incorporated so users could momentarily relax their hands without losing control of the tool.
At that time, we had an ergonomist on staff. The trimmer is designed to increase yield, and that excites the buyers, but reducing worker fatigue also is important. Trimming meat from bone or fat is boring, hard work. Workers are stressed after eight hours. Making the job easier is a major R&D goal. The ergonomist went into the plants with us and conducted EMG (electromyography) measurements to determine how workers’ muscles reacted to the tool’s vibration. Vibration measurements were taken in three axes while the tools were in use. Carpal tunnel syndrome was a concern, and we wanted to ensure the tools weren’t aggravating the problem.FE: What are the key research objectives?
Whited: Improve yield, reduce maintenance and improve worker comfort. We’ve learned that higher blade revolutions per minute usually make trimming easier, but a higher rate produces amplified vibration, greater drag and increased wear on metal parts. We’ve worked on different gear designs and tried to hold the rotating blades stable in the center of the tool. We tried a three-speed motor, which allowed speed adjustments, but eventually we concluded the highest speed was the one most operators liked.
We also learned that lighter wasn’t necessarily better. If meat is positioned on a flat surface, there’s actually less operator fatigue with a heavier tool. On the other hand, if workers are cutting chickens on an overhead line, reducing weight is beneficial. We experimented with many different blade edges, finally settling on a micro-serration that holds its sharpness longer than if the edge is smooth. FE: How do food production’s hygienic requirements impact trimmer design?
Whited: Today’s tools have fewer parts and are easier to disassemble for cleaning. Probably the biggest impact is in the choice of materials of construction, which is limiting. Coatings technology that comes out of NASA and automotive offers significant advances in performance and wear-resistance, but much of it can’t be used in direct food contact. We use some 440C stainless steel and an alloy with a 59 Rockwell, but the best overall edge-holding materials for our blades is not necessarily stainless. FE: Eight years ago, you collaborated with a German group to develop a trimmer combined with a vacuum system. How did that partnership come about?
Whited: The gentleman who came to us with that idea was one of our European distributors. The vacuum trimmer was developed for removing spinal membrane and spinal cords from cattle after the carcass was split. Mad Cow was already an issue in Europe, and the first US incident occurred about the same time as the tool was introduced. We tried to adapt the system for pork processing, but it was too cumbersome and the line speeds too fast.
More recently one of our salesmen got the idea of using the system on poultry cone lines. About half an ounce of breast meat under the wishbone typically is not harvested with the other white meat. It either goes to rendering or is recovered later and mixed with lower-value trimmings. Adapting the spinal cord system required very little time for the tool itself; a blade already existed for stripping meat from a pork rib. A bigger issue was the vacuum. A large hose is used for cattle, and the system is flushed with water. We can’t add water to an edible product, and the hose needs to be a short run. We’re still working out some vacuum issues.FE: How has newer drive technology impacted the tools?
Whited: Originally the tools were powered by small 1,725 rpm electric motors with flex shaft drives, but different approaches to power have been tried. Two electric motor options now exist, including a washdown-rated motor at 5,000 rpm. Our air shearers have a servo mechanism that causes the scissor to do whatever the user’s hand does, and the gyros carver has a DC motor in the handle.
The most common set-up is to hang the motor behind and to the side of the operator, with a flexible drive shaft connecting it to the trimmer.FE: As technology changes, how has the makeup of the R&D staff changed?
Whited: Twenty years ago, we had two or three engineers and a lot of designers who learned their craft using drafting boards. Now we have degreed engineers, mostly mechanical but also an electrical engineer who serves as the lab supervisor. Occasionally we call on an electronics expert for support.