Linear Motion Medical Applications for Animals

Healthy animals are necessary for efficient stockyard production. Disease and other bacterial conditions thrive in close quarters; making regular vaccination for all livestock a natural pre-requisite. However, implementing and documenting consistent injections for all animals is tedious, expensive and, in some cases, hazardous. To solve these problems, Acushot, an innovative vetrinary design company, designed an automated, needle-free injection gun for mass livetock vaccination. The design required a linear bearing system to absorb recoil. Acushot™ turned to Colpitt Designs, who recommended PBC Linear’s Simplicity® plane bearings for the task.

Typically, hand-held needle injections were used for vaccinating the animals in the stockyards and barnyards; however, with thousands of animals coming through production at once, succesfully and safely supervising the injections became an increasing concern. Acushot’s new system elilminated needles, removing the possibility for an unsafe employee needle-slip. The unit also enhances sanitary conditions. The battery powered injection unit can be used hundreds of times without risk of cross contamination to the animals.

For a rapid prototype and possible added refinements to their design, Acushot™ turned to Colpitt Designs—a third party engineering firm. Colpitt worked to reduce components and assemble the triggering/injection system by using a gas cylinder with varying degrees of strength to provide up to 600 pounds of force. The system also automatically saves each dose with a time stamp for accurate vaccination records. The cylinders are designed to inject the vaccines to the same recommended depth as a typical needle that would have been used on a range of animals. The injector can be set at a low threshold of 0.2cc and deposited just in the skin of the animal, or set up to 2.5cc and injected to the recommended depth into the muscle of the animal.


Colpitts immediately set to work. Using a simplified approach, they were able to reduce moving components and make the design more cost-effective, while still adhering to Acushot’s criteria. The final product was a lightweight, compact and battery powered needle-less injection unit that packed up to 28,000 psi delivery pressure, while concurrently documenting each injection.

One obstacle to overcome was finding a linear bearing assembly to support the force of the injection delivery. Throughout the cycle, 650 lbs of force act continuously on the bearings under extreme temperatures and outdoor working conditions. To solve this, Colpitts Designs used Simplicity® plain bearings to withstand the system parameters and harsher environments of the application.

Simplicity bearings glide using a proprietary Teflon liner. This provides even disbursement of forces throughout the bearing and smooth, reliable travel. Bronze and linear ball bushings spall the shafting under the high forces and short stroke which accumulate and contaminate the system; resulting in catastrophic failure. Simplicity bearings self-lubricate to ensure smooth and quiet operation for constant or intermittent use. They also thrive in temperature extremes (from -400°F-400°F)! These design factors allowed Simplicity to drive consistent and satisfactory performance of Acushot’s injection gun.

No needle trauma recovery was necessary for the animals. In fact, the livestock do not even take notice when given their injection with Acushot’s new injector. It also reduced the diameter of the injection mark to about 1/8th the size. The Acushot system has been found to be easy to use with no extra vaccine containers, and has improved productivity, safety and the overall health in stockyards and barnyards world wide.

For more info on Acushot or Colpitts Designs, please visit them at their respective websites:

For more information on PBC Linear or Simplicity technology, please email us at You can also contact us by phone at 1.800.962.8979.