BACKGROUND
This invention relates to tools for automated cutting or milling machines. Generally, milling machines are used to machine metal into finished manufactured parts. To manufacture parts quickly and efficiently, milling machines can be numerically programmed to perform repetitive production machining operations on a plurality of work pieces. Each work piece must be secured in place with some type of fastener prior to beginning the machining process. Currently, each work piece is secured in place manually with some type of work holding device such as vise, chuck, clamps etc. What is needed is a tool which can be controlled by a numerically programmed milling machine for tightening or loosening fasteners that hold work pieces in place.
SUMMARY
The present invention provides a tool for attachment to a milling machine. The tool of the present invention provides the capability of automating the tightening and the untightening of fasteners required to secure work pieces in place during the machining process. The present invention significantly decreases the time it would take to secure each work piece on the work table during the cutting process, thereby increasing production.
The tool comprises an elongated hollow housing defined by a neck section, a middle section, and a bottom section. The neck section is adapted to engage a spindle of the milling machine for rotational and axial movement therewith. A torque spring is situated within the middle section of the housing. A torque adjuster is dimensioned and configured to sit within the neck section of the housing on top the torque spring. The torque adjuster provides the capability of setting the torque spring to a predetermined torque threshold level. A bit holder is rotationally mounted to the bottom section of the housing. A driver mechanism is interposed between the bit holder and the torque spring. The driver mechanism is coupled to the bit holder for simultaneous rotation therewith. When the torque threshold is reached by the bit holder, the driver mechanism rotationally disengages from the bit holder. The system further includes a means for automatically controlling the rotation of the bit holder until the predetermined torque.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a frontal view of the present invention with each component separated.
FIG. 2A is a bottom view of the barrel.
FIG. 2B is a top view of the barrel.
FIGS. 2C and 2D are cross-sectional views of the barrel.
FIG. 3 is a side view of the torque adjuster.
FIG. 3A is a top view of the torque adjuster.
FIG. 4 is a side view of the bit holder.
FIG. 4A is a top and opposite side view of the bit holder.
FIG. 5 is an exploded top view of the driver mechanism.
FIG. 5A is an exploded bottom view of the driver mechanism.
FIG. 6 is an exploded top view of the cap for the bit holder.
FIGS. 6 and 6A are an exploded bottom view of the cap and bit holder.
FIG. 7 illustrates a plurality of work pieces along with the tool in place above a plurality of work pieces.
DETAILED SPECIFICATION
Referring to FIG. 1, there is shown a frontal view of the present invention, a tool (10) attachment for an automated cutting or milling machine (5) as shown in FIG. 7 which will be described below. Tool (10) further comprises an elongated hollow barrel (100) defined by a neck section (110), a middle section (115), and a bottom section (120). The internal hollow configuration of housing (100) and cap member (127) are adapted to enclose and to support each mechanical component (125) of tool (10) as described below. Tool (10) can be made of steel alloy or another suitable material.
Referring to FIG. 2A, there is shown a frontal view of barrel (100). In the illustrated embodiment, middle section (115) and bottom section (120) of barrel (100) are cylindrical in shape. The internal diameter of section (115) encompasses torque transmitter (570) (show in FIG. 1). Bottom section (120) internal configuration is adapted to encompass driver mechanism (300) and bit holder (250) shown in FIG. 1.
Circumferentially surrounding the bottom opening of barrel (100) is a plurality of bores (128). Each bore is adapted to support the engagement of fasteners utilized to secure cap member (127) (shown in FIG. 1) to the bottom of barrel (100). In the illustrated embodiment, each bore is threaded to support the engagement of the fasteners. Referring to FIGS. 6 and 6A cap member (127) further comprises a plurality of bores (350) which aligns over bores (128) when cap member (127) is placed over the bottom of barrel (100). Cap member (127) is then secured with fasteners which secure bit holder (250) in place. Bit holder (250) is adapted to protrude through opening (345) in cap member (127)
Referring to FIG. 2B, there is shown a top view of barrel (100). Neck section (110) of barrel (100) is formed upon the top of middle section (115). Neck section (110) further comprises lid member (116) formed upon the top of barrel (100). Tubular portion (118) is formed upon lid member (116). Tubular portion (118) projects outward to a predetermined distance from lid member (116). Internal bore (117) is formed within tubular portion (118) along axis (112).
FIG. 3 illustrates an exploded side view of one embodiment of torque adjuster (200). Torque adjuster (200) further comprises cylindrical shape plate member (210) having an upper surface area (211) and a lower surface area (212). Plate member (210) is configured and dimensioned to seat inside the top circular opening of middle section (115) of barrel (100) illustrated in FIG. 2B. As depicted, torque adjuster (200) further comprises a cylindrical elongated top portion (215) formed upon the upper surface area (211) of plate member (210). Top portion (215) projects outward from the upper surface area (211) of plate member (210) to a predetermined distance. Additionally, top portion (215) is dimensioned and configured to slide into internal bore (117) of neck section (110) illustrated in FIG. 2B.
As shown in FIGS. 2C and 2D, internal bore (117) is adapted to receive an adjustment fastener (400) which is utilized to compress and uncompress upon top surface (220) of top portion (215). The adjustment fastener (400) can be a conventional set screw. Internal bore (117) is threaded throughout its internal diameter to receive the adjustment fastener (400).
Referring back to FIG. 1, lower surface area (212) of plate member (210) sits upon torque transmitter mechanism (570). As depicted torque transmitter mechanism (570) is a spring. In operation, the adjustment fastener (400) is rotated until the desired torque threshold is achieved. The bottom of the adjustment fastener (400) sits upon lower surface (212). As the adjustment fastener (400) is rotated, the bottom of the adjustment fastener (400) compresses upon lower surface (212) which in turns compresses spring (570). Spring (570) is compressed to increase the torque threshold level and spring (570) is uncompressed to decrease the torque threshold level. As the spindle of the milling machine rotates, the spindle also moves downward to maintain the constant set torque threshold level. Referring to FIGS. 1 and 2A, barrel (100) further comprises a pair of parallel elongated slits (25). Slits (25) form an opening on each opposing side of barrel (100). In operation, an operator can view the compression of spring (570) within slits (25) of barrel (100).
Referring to FIG. 4, there is shown an exploded view of bit holder (250). Bit holder (250) further includes plate member (265) which is defined by an upper surface (271) and a lower surface (270). Plate member (265) has a cylindrical shape with a circumference dimensioned and configured to seat within the internal diameter of bottom section (120) as shown in FIG. 1.
Referring to FIG. 4A, there is shown an exploded top view of bit holder (250). The upper surface (275) has a plurality of pockets (280) adapted to fit a plurality of ball bearings. In the present invention each ball bearing is a sphere. Each pocket (280) is adapted with sufficient depth to receive a portion of the area of each sphere. Bottom portion (260) is formed upon the lower surface (270) of the plate member (265) and projects outward to a predetermined distance therefrom.
As shown in FIG. 4, hole (251) is formed within the bottom portion (260). Hole (251) is adapted to fit bit (255). Bit (255) can be exchanged to support the tightening and untightening of a plurality of different type of fasteners utilized to secure work pieces during the machining process.
Referring to FIG. 5, there is shown an exploded view of driver mechanism (300). Driver mechanism (300) has a cylindrical shape with a circumference dimensioned and configured to seat within the internal diameter of bottom section (120) upon bit holder (250) as shown in FIG. 1. Driver mechanism (300) further comprises plate member (317) which is defined by an upper surface (318) and a lower surface (315). Plate member (317) is dimensioned and configured to seat within the bottom section (120) as shown in FIG. 1. The lower surface (315) of plate member (317) has a plurality of pockets (310) adapted to fit a plurality of ball bearings. Each pocket (310) is adapted with sufficient depth to receive a portion of the area of each sphere. As shown in FIG. 5A, upper surface (318) is substantially flat. Within bottom section (120), upper surface (318) abuts the bottom of spring (570) as shown in FIG. 1.
Driver mechanism (300) further comprises locking mechanism (320) for securing driver mechanism (300) in place within the internal diameter of bottom section (120) as shown in FIG. 1. As depicted, the locking mechanism (320) further comprises aperture (325) and pin (320). Aperture (325) emanates through the center of the side of plate member (317). Aperture (325) is adapted to receive pin (320) which firmly secures the driver mechanism (300). Each edge of pin (320) sits within each opposing slit (25) of barrel (100) as shown in FIG. 2A. As drive mechanism (300) rotates, each edge of pin (320) reciprocates within slit (25) as soon as the drive mechanism reaches its torque threshold.
To form a cage for the ball bearings, the lower surface (315) of the plate member (317) of driver mechanism (300) in FIG. 5 is aligned over the upper surface (275) of plate member (265) of the bit holder (250) shown in FIG. 1. Ball bearings are interposed between driver mechanism (300) and bit holder (250) with a slight gap such that lower surface (315) and upper surface (275) do not abut. The ball bearings allow driver mechanism (300) and the bit holder (250) to simultaneously rotate together. When bit holder (250) exceeds the torque threshold, the driver mechanism (300) and the bit holder (250) rotationally disengages. The ball bearings are locked in place in the cage until the driver mechanism (300) disengages from the bit holder (250). Once disengaged, the driver mechanism continues to rotate jumping one pocket at a time over each ball bearing until the spindle of the machine stops rotation. The bit holder (250) ceases to rotate while the rest of tool (10) continues to rotate until the spindle of the milling machine stops rotation.
The system further comprises an automation component which is part of a numerical program for a milling machine. The automation component controls the rotation of the spindle until the driver mechanism (300) exceeds the predetermined torque threshold and rotationally disengages from the bit holder (250) as shown in FIG. 1. The automation component comprises two automated subcomponents (1) an automated tightening component for securing each work piece in place prior to beginning the machining process and (2) an automated untightening component for unsecuring each work piece when the machining process is over. The automated tightening component controls the placement of the tool (10) directly over each fastener (not shown) required to secure the work piece in place, the torque applied in forward direction to fastener to secure the work piece in place, and return of the tool (10) to its home position. The untightening component controls the placement of the tool (10) directly over each fastener (not shown) required to unsecure the work piece from the milling machine work table, the torque applied in a reverse direction to fastener to unsecure the work piece, and return of the tool (10) to its home position.
Referring to FIG. 7, generally, a numerical controller (270) is used to automate the operation of a milling machine. In normal operation, the operator would load the numerical program into numerical controller (270) for performing a series of operations on a work piece. The individual tools required to perform the operations are placed within a cache (272). Then, the numerical controller (270) controls the process of loading each required tool in series from the cache (272) of tools into the spindle of the milling machine, perform the operation on the work piece and return the tool back to the cache (272). At the end of the operation, the spindle of the milling machine (5) is returned to its home position.
In operation, the present invention is just another tool located in the cache. Referring to FIG. 7, the operator of the milling machine (5) chooses a bit (255) to be place within the bit holder (250). The operator compresses the torque spring to the desired torque threshold level as discussed above. The tool of the present invention is placed within the cache of the milling machine (5). Then, the numerical program including the automation component of the present invention is loaded into the numerical controller as part of the overall machining operation. A plurality of work pieces (6) are secured in some type of holding fixture which is secured upon the work table. Finally, the operator presses the start button on the numerical controller to begin the machining process. The tool holder (4) of the milling machine (5) is adapted to engage neck section (110) for rotational and axial movement along the central axis line. The tool (10) performs the tightening and untightening of work pieces (6) as part of the overall machining process.
Patent Application
20060053619
