A bar clamp specifically designed for use with hockey puk devices would likely be a clamping tool that is used to mount hockey puk semiconductors to heat sinks. The clamp would have a mechanism for holding the semiconductor in place and applying a clamping force to keep it securely attached to the heat sink.
The clamp may have a stack of preloaded Belleville springs, which help to guarantee the perpendicularity of the clamping force. It may also have an indicator washer on the spring guide to indicate when the correct clamping force has been achieved.
This type of bar clamp would be used in double-sided cooling applications, where it is necessary to dissipate heat from both sides of the semiconductor. It would be an important tool in the operation and maintenance of hockey puk devices, as it would help to ensure that the semiconductors are securely attached to the heat sinks and are able to effectively dissipate heat.