Patent ID: 8544154

Claim:
A clamp assembly for selectively gripping material, the clamp assembly comprising: a housing having a first end, a second end, a first portion and a second portion, the first and second portions cooperating to define a material receiving slot therebetween, the material receiving slot extending from the first end of the housing and terminating a distance from the second end of the housing, the first portion of the housing having a channel angularly disposed relative to the material receiving slot and a slot formed therethrough, the channel having a first end terminating a distance from the first end of the housing and a second end terminating a distance from the second end of the housing, the second portion of the housing having a gripping surface; a gripping assembly slidably disposed within the channel and through the slot such that the channel and the slot cooperate to define a travel path so that the gripping assembly is selectively movable between a biased first position and a second position, the gripping assembly having a guide plate disposed on an outer surface of the first portion of the housing and a neck member connected to the guide plate so that the neck member extends into and through the slot of the first portion of the housing, the gripping assembly further comprising at least two cylindrical rollers rotatably connected to a lower end portion of the neck member with at least one roller positioned on each side of the neck member in axial alignment with the other roller, in the biased first position the rollers extending into the material receiving slot in such a way as to cooperate with the gripping surface of the second portion of the housing to grip material positioned in the material receiving slot and in the second position the rollers being substantially withdrawn from the material receiving slot; and a spring positioned in the channel of the housing for biasing the gripping assembly in the biased first position, the spring having one end engaging the gripping assembly and another end engaging the second end of the housing, the spring having a tapered configuration with a smaller end engaging the gripping assembly and a larger end engaging the second end of the housing.