Abstract:
A reciprocating pneumatically driven drill motor housing for use in repetitive machining operations that uses industry standard motors, chucks and multiple spindle heads. The invention allows the user to limit set up time and obviates the need for fabricating special tooling. The unit is easily mounted on any type of fixture.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to devices for repetitive machining operations. A need exists in industrial manufacturing for a device that can be mounted on a fixture and used on an assembly line or secondary machining line that can perform actions such as drilling, routing and the like. In most of these types of operations the devices used for secondary machining are fabricated by the shop doing the work, are specifically designed for the job and have little if any other use. 
       SUMMARY OF THE INVENTION 
       [0002]    The present invention provides a device that can easily be mounted on any type of fixture and eliminates the need for fabricating special tooling. The device is designed to use and take advantage of industry standard motors and tooling, limiting down time and obviating the need to design and fabricate special tooling. The invention presented is a pneumatically actuated, reciprocating slide mounted housing which accepts industry standard pneumatic motors, chucks and tooling. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL DRAWINGS 
         [0003]      FIG. 1  is a perspective view of the invention from the top right side. 
           [0004]      FIG. 2  is an exploded view of the invention showing the relationship of it&#39;s parts. 
           [0005]      FIG. 3  is a perspective view of a collar and drive shaft used for a multiple spindle head. 
           [0006]      FIG. 4  is a perspective view showing the underside of the top portion of the invention. 
           [0007]      FIG. 5  is a plan view of the invention from the left side. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0008]    Referring to  FIG. 1 , the Drill Unit  10 , and its main components can be seen. An exploded view is shown in  FIG. 2 . The Drill Unit  10  comprises a Motor Housing  45 , a Bearing Block Mounting Plate  47 , a Cylinder Mounting Plate  48 , a Pneumatic Cylinder  16  (not shown in  FIG. 1 ), Bearing Blocks  11 , Rail Bearings  12 , a Velocity Controller  14 , a Stop Block  51  and Limit Detectors  42 . The Drill Unit  10  is constructed so the Motor Housing  45  is free to move in an axial direction along the Rail Bearings  12  while being constrained from lateral or vertical movement. Axial movement is induced by the Pneumatic Cylinder  16  which is bi-directional and will move the Motor Housing  45  back and forth along the Rail Bearings  12 . The motor is not shown in  FIG. 1 , but a Chuck  54  attached to the motor is shown as it would be in use. Different motors are used for different jobs depending upon the speed, horsepower and torque needed. The motors are industry standard pneumatically driven motors. The motor is held in place using Set Screws  56  which extend through the Motor Housing  45 . The Set Screws  56  are provided on both sides of the Motor Housing  45 . The front of the Motor Housing  45  has a plurality of mounting holes shown at  45   a . These allow the attachment of a Collar  60  shown in  FIG. 3 . The Collar  60  allows a multiple spindle head to be attached to the Drill Unit  10 . The motors used in the Drill Unit  10  have threaded output shafts. The chucks used are threaded onto the motor shaft. When a multiple spindle head is used, it is attached to the Collar  60  using a collet supplied with the spindle head. The collar  60  is supplied with a keyway to prevent the spindle head from slipping. Because of the length of the drive mechanism for a multiple spindle head, an Extension Shaft  61  is supplied with the Drill Unit. The Extension Shaft  61  is threaded on one end to attached to the shaft of the drill motor, and has a square key on the other end that fits into a slot on the input shaft of the multiple spindle head. The Bearing Block Mounting Plate  47  and the Cylinder Mounting Plate  48  are generally rectangular in shape and made from aluminum to decrease weight, although other materials could be used. 
         [0009]    Referring to  FIGS. 2 and 4 , an exploded view of the invention can be seen and a view from the bottom of the Motor Housing  45 . The Motor Housing  45  has an axially elongated Cylindrical Cavity  45   c  at its upper region that is sized to accept a wide variety of standard motors. The motor is inserted from the Front Face  45   a  of the Motor Housing  45 . Air supply to the motor is provided by a line running through a Sleeve  24  and exhausted through a muffler  23 . Again referring to  FIGS. 4 and 2 , the position and attachment means of the Rail Bearing  12  can be seen. The two parallel Rail Bearings  12  are mounted to the underside of the Motor Housing on two axial, downwardly extending Legs  45   f , one on either side of the Motor Housing  45 , along it&#39;s outer lower edge. The downwardly extending legs define a space to accommodate the Pneumatic Cylinder  16 . The Rail Bearings  12  ride in the Bearing Blocks  11 , two of which are provided for each Rail Bearing  12 . The Bearing Blocks  11  are mounted on the Bearing Block Mounting Plate  47  and spaced apart to provide support and accommodate linear movement of the Motor Housing  45 . The Bearing Block Mounting Plate  47  is mounted to the Cylinder Mounting Plate  48 . The Bearing Block Mounting Plate  47  is provided with a channel running lengthwise to accommodate the body of the Pneumatic Cylinder  16 . The Pneumatic Cylinder  16  is also secured to the Cylinder Mounting Plate  48 , on top of the Bearing Block Mounting Plate  47 , the body of the Pneumatic Cylinder  16  extending along the channel. The Pneumatic Cylinder  16  has a Threaded Shaft  17  extending from its body. The Threaded Shaft  17  is typical of these types of cylinders. Other means of attachment such as retaining clips can be used and are well known in the art. The use of a cylinder with a threaded shaft is not part of the inventive quality of the present invention, nor is it meant to limit use to cylinders with threaded shafts. The Cylinder  16  is secured to the Motor Housing  45  by means of the Threaded Shaft  17  and a Locking Nut  31 , thereby providing the moving force for the Motor Housing  45 . The Pneumatic Cylinder  16  is a standard bi-directional pneumatic cylinder. These types of cylinders require two ports for the introduction and release of compressed air, both of which serve alternately as supply or exhaust ports depending on which direction the cylinder is moving. Flow Control Valves  44  at the ports introduce or exhaust air as required. The  44  are industry standard three way valves having an air inlet, an air outlet and an exhaust orifice. Air pressure is supplied to the inlet of the  44  and introduced to the Pneumatic Cylinder without modification. Air is exhausted through the other  44  through the exhaust orifice. The exhaust orifice is sized to limit the speed of travel of the  45  and prevents it from banging back and forth and damaging the unit. To make the Drill Unit  10  more easily used, an Air Channel  48   a  is provided in the Cylinder Mounting Plate  48  to direct the air flow from the bottom of the Cylinder  16  to the rear of the Reciprocating Mounting Unit  10 . This way, all of the air lines run out the back of the unit and do not interfere with mounting or movement of the unit as a whole. When in use, the Reciprocating Mounting Unit  10  will usually be mounted on a fixture using the Mounting Holes  48   b  provided in the Cylinder Mounting Plate  48 . 
         [0010]    Referring again to  FIG. 1 , the mode of movement of the invention will be described. The Motor Housing  45  is free to move axially along the Rail Bearings  12 . Forward movement is limited by the Stop Block  51  which comprises an Adjustable Stop Pin  28 . The Adjustable Stop Pin  28  will generally be an elongated threaded bolt with a Locking Nut  30  to keep it from moving. During forward movement of the Motor Housing  45 , compressed air is applied to the Cylinder  16 , moving the Threaded Shaft  17  outward. The Threaded Shaft  17 , being secured to the Motor Housing  45 , will move the Motor Housing  45  forward within the constraints of the Rail Bearings  12 . The Motor Housing  45  will move forward at a rate determined by Cylinder  16  until it is about to engage a work piece. At a distance set by the operator, the Velocity Controller  14  will engage the Adjustable Stop Pin  28 . Forward velocity of the Motor Housing  45  will there after be limited by the Velocity Controller  14 . The Velocity Controller  14  is a type of shock absorber device well known in the art having an external pin  14   a  and an internal plunger. When the external Pin  14   a  impinges upon the Adjustable Stop Pin  28 , an air volume inside the Velocity Controller  14  is compressed and allowed to bleed out in a controlled fashion which regulates the forward movement of the Motor Housing  45 . The Motor Housing  45  travels forward at a speed determined by the exhaust orifice in the Control Valve  44  until the external pin  14   a  is engaged. Then the speed is reduced and controlled by the Velocity Controller. The Velocity Controller is adjustable and the speed at which the Motor Housing moves forward after the Velocity Controller is engaged may be set by the operator. The forward travel of the Motor Housing Unit  45  will be terminated by reversing the action of the Cylinder  16  when the desired forward movement is attained. 
         [0011]    Referring to  FIG. 5  the method of determining the position of the Motor Housing  45  will be described. The position of the Motor Housing Unit  45  is determined by a Limit Detector  42  attached to the Front Limit Detector Mounting Block  49 . Similarly, rearward movement is detected by a Limit Detector  42  attached to the Rear Limit Detector Mounting Block  50 . The limit detectors used in the present invention are proximity detectors of a type well known in the art. They will note the proximity of the forward and rearward edge of an adjustable Limit Actuator  53  which can be seen in the exploded view of  FIG. 2 . A signal is sent from the Limit Detectors  42  to a controller for the Pneumatic Cylinder  16 . The signals are used to actuate the Pneumatic Cylinder  16 , causing forward or reverse movement, or ceasing movement altogether. The rearward end of the Limit Actuator  53  is fixed, and the forward end is adjustable. Adjustments in the length of the Limit Actuator  53  are made by using a Threaded Bolt  27  and Locking Nut  29 . In keeping with the concept of universality of the invention it should be noted that the ancillary components are easily obtainable and will not require the end user to either fabricate or purchase special parts in order to make modifications or repairs to the unit. 
         [0012]    Referring to  FIG. 4 , a bottom view of the Motor Housing  45  is presented. In this view, the downwardly extending Legs  45   f  which the Rail Bearing  12  are secured to, can be seen. It can also be seen how the legs provide clearance for the body of the Cylinder  16 . In the preferred embodiment, the Motor Housing  45  is a single piece, either machined or cast from aluminum. The upper portion of the Motor Housing  45  includes an axially extending Cylindrical Cavity  45   c  for holding and securing a motor. A motor is inserted into the Motor Housing  45  through an opening in the front face  45   a  and secured into the cylindrical cavity,  45   c . The motor is secured in the cavity  45   c  and held in place using a plurality of set screws using threaded holes  45   d . At the front of the Motor Housing  45  on it&#39;s lower edge an elongated buss  45   b  is provided to secure the Threaded Shaft  17  of the Cylinder  16 . A second elongated buss  45   e  is provided on the side of the Motor Housing  45  to secure the Velocity Controller  15 .