Computerized numerical controlled (CNC) machines are unique automated machines capable of forming small intricate end-use products from material stock with great precision and accuracy. As with all CNC machining operations, the ability to control output in terms of an acceptable finished product for the least amount of cost is of the utmost importance to today's production shop. To realize this goal as well as others, the CNC machine is typically fine tuned to the extent of programming the controller for intricate manipulation of the tooling rack in specified axial directions (X, Y, and Z axes or a combination of each), spindle speed and direction (fast or slow, forward or reverse), coolant flow (on or off), and material feed rate (fast or slow), to name a few programmable features of today's most advanced CNC machines.
Besides the most noted programmable features and operable components inherently made part of the CNC machine, the CNC machine may require the presence of operable external means for feeding material stock into and through the headstock spindle assembly. The most primitive approach may involve operator placement of material stock into the headstock spindle assembly of equivalent length and upon completion of interim machining operations, push or grab the material stock through the spindle assembly to permit further machining thereof or subsequent extraction of the finished product. Although this approach may be suitable for CNC machining operations involving low production runs, it is most commonly employed with turning and milling machines lacking programmable capabilities, such as a manually operated lathe having chucking means made available for supporting and holding the workpiece during machining operations. A more sophisticated approach, on the other hand, may utilize a bar feeder having ample storage capacities and automated means for loading and advancing the material stock into and through the headstock spindle assembly, respectively. An alternative approach for feeding material stock, generally of equivalent sophistication as a bar feeder but lacking ample capacity, may involve the use of a bar puller which pulls on the material stock rather than pushing it through the headstock spindle assembly. In typical applications, the bar puller is generally positioned at the machine's turret station, laterally away from the headstock spindle assembly.
Because of the inherent desire to maximize profit, the production shop often avails itself to the use of automated equipment, such as bar feeders having ample capacities and more or less automated features to cooperate with those most notably present in the CNC machine. However, in some instances, the use of automated bar feeders of the type noted herein can be cost prohibitive in terms of capital investment, operating cost, downtime for changeover and adjustments, spatial requirements, and so forth. Conversely, the simple placement and movement of material stock by operator means may fail to meet the timely demands and requirements of today's production shop.
Accordingly, there remains a need for a material advancing apparatus capable of cooperating with the operable components of the turning and milling machine, regardless of its programmable capabilities, to yield finished parts and the like within reasonable timeframes and of acceptable quality without the undue costs and spatial requirements often associated with prior art devices.