are mounted to relatively small frame bars 35 and biased against compression springs 36 which are supported beneath a frame crossarm 37 the pair of guide bars 28 29 and the pair of guide bars 30 31 are mounted at a slightly skewed angle with respect to the vertical plane 27 fig3 whereby they diverge slightly away from the plane as they extend from their y shaped entry end towards their rear ends indicated generally at 39 a pair of rotary disk blades 40 and 41 are mounted to the ends of rotary shafts 42 and 43 which are driven by fractional horse power electric motors 44 and 45 respectively it will be noted that the shafts 42 and 43 are located along shaft axes which are inclined as they extend from their respective motors towards the disk blades it will also be seen that the shafts are not perpendicular to the path of travel of the conveyor but rather are cocked at a sight acute angle contra to the direction of conveyor movement this is done in order to position the rotary cutting blades 40 and 41 closely adjacent and between the two pairs of guide bars for making clean high speed cuts through the shoulder joints of birds as hereinafter described preferably the rotary blades are driven at a speed of some 1725 rpm although other speeds may be employed finally several adjustment mechanisms are provided for altering the positions of the various elements of the apparatus as shown in fig1 these adjustments include a rack and pinion assembly shown partially at 50 for altering the elevation of the entire apparatus with respect to the overhead conveyor by rotation of a crank 51 for clarity only a portion of this adjustment mechanism is illustrated in the detailed fig1.