Patent ID: 8789520

Claim:
A crossbow for shooting an arrow, the crossbow comprising a bow frame extending between a front end and a rear end, the bow frame including a trigger assembly configured to selectively interengage with a bow string to control the firing of the crossbow, the crossbow further including a firing system joined relative to the bow frame, the firing system having a single spring assembly having at least one spring that is actuateable between an unloaded condition and a fully loaded condition wherein the spring assembly has a designated amount of stored energy to propel an associated arrow when in the loaded condition, the spring assembly having an exposed spring plate that moves with the actuation of the at least one spring, the firing system further including a first crank rotatably attached relative to the bow frame about a first crank axis and having a first spring leg and a first string leg with a first pivot region joining the first spring and string legs, the first spring leg being shaped to engage the exposed spring plate, the string leg having a first mount to rotatably support a first rotatable bow string support about a first support axis wherein the first support includes a first outwardly facing guide groove for a bow string that is guided therein about the first support axis; the firing system further including a second crank rotatably attached relative to the bow frame about a second crank axis that is spaced from the first crank axis, the second crank having a second spring leg and a second string leg with a second pivot region joining the second spring and string legs, the second spring leg being shaped to engage the exposed spring plate, the string leg having a second mount to rotatably support a second rotatable bow string support about a second support axis wherein the second support includes a second outwardly facing guide groove for the bow string that is guided therein about the second support axis; the bow string being joined between the first and second first rotatable bow string supports wherein when the bow string is pulled from an at rest condition to a full drawn condition the first and second rotatable bow string supports rotate and are urged toward one another thereby rotating the first and second cranks about the first and second crank axes thereby compressing the at least one spring, the at least one spring springs providing an amount of stored energy to propel an associated arrow when the bow string is released by the trigger assembly.