Patent Application
20190070670
This disclosure generally relates to boring bar heads used for machining holes. More specifically, the presented embodiments relate to an adjustable boring bar head used for machining deep holes with a closed and flat bottom.
Machining deep and flat bottomed holes is a difficult and cumbersome process. Drill shafts used for deep holes lack rigidity, causing the drill shaft to vibrate. The vibrations cause a rough finish and the bottom of the hole may not be smooth. For deep holes, bore heads can be used due to their increased rigidity. However, bore heads interfere with cutting the center of the hole, leaving a hump or conical shape in the center of the deep hole because the bore head can drill the perimeter of the bottom of a deep hole but not the center of the bottom of a deep hole. Therefore, there is a need for machining a deep hole with a closed and flat bottom.
According to one aspect of the invention, a boring bar head body has a front face, an attachment face opposed to the front face, and an axis substantially perpendicular to the front face and attachment faces. The attachment face is operably connected to a boring bar. The front face has a low plane, a high plane, an insert groove in between at least a portion of the high and low planes, and at least one cutting insert disposed in the insert groove. The high and low planes are disposed substantially orthogonal to the axis. The boring bar head has a first length and a second length. The at least one cutting insert has a cutting surface and a bottom surface. The cutting insert is removably attached to the insert groove. The cutting surface extends to a third length.
Embodiments of the present invention are illustrated in the accompanying figures where:
While the present invention may be embodied in many different forms, disclosed herein are specific illustrative embodiments thereof that exemplify the principles of the invention. It should be emphasized that the present invention is not limited to the specific embodiments illustrated.
The present invention generally relates to a boring bar head 140 for machining a deep hole with a closed and flat bottom. Referring to
The attachment face 146 is removably attached to a boring bar 150 through connection means 149. Removably attached means the attachment face 146 is secured to the boring bar 150 through connection means 149 in a way that allows for unlimited connection, disconnection, and repositioning of the attachment face 146 to the boring bar 150. In an embodiment, the connection means 149 is a dial screw. In another embodiment, the connection means 149 is a dovetail joint.
A boring bar 150 is a tool used in metalworking for boring or enlarging and shaping pre-drilled holes. Typically, boring bar heads 140 are used to bore holes into metal pieces. A boring bar 150 may have several boring bar head bodies 142 connected to it. Different boring bar head bodies 142 perform different functions including, but not limited to, cooling, roughing, shaping, and smoothening. Different boring bar head bodies 142 allow different types of holes to be bored or finished into metal pieces. The holes that are bored can vary in size, shape, depth, and surface finishes.
The front face 144 has a low plane 120, a high plane 110, an insert groove 160, and at least one cutting insert 100. The low plane 120 and the high plane 110 are two surfaces that create the foundation of the front face 144. The low plane 120 and the high plane 110 may be disposed at different distances from the attachment face 146. In an embodiment, the low plane 120 and the high plane 110 of the front face 144 are substantially perpendicular to the axis 148. In an embodiment, the low plane 120 is parallel to the high plane 110. The high plane 110 has a first length 112 that is measured as the distance between the highest point of the low plane 120 and the highest point of the high plane 110. The low plane 120 has a second length 122 that is measured as the distance between the lowest point of the attachment face 146 and the highest point of the low plane 120. In an embodiment, as shown in
The insert groove 160 is between at least a portion of the high plane 110 and at least a portion of the low plane 120. The insert groove 160 extends radially inward toward the axis 148 beginning at or near a perimeter edge 170. The perimeter edge 170 is the edge surrounding the front face 144. In an embodiment, the insert groove 160 begins on the perimeter edge 170. In another embodiment, the insert groove 160 begins at a point inside the perimeter edge 170. The insert groove 160 can intersect the axis 148 or bypass the axis 148 along a chord. A chord is a line segment that spans two points on the perimeter edge 170 without intersecting the axis 148. The insert groove 160 extends radially toward the axis 148 and ends at the insert groove end point 162 beyond the axis 148. The insert groove 160 is sized to receive at least one cutting insert 100.
The at least one cutting insert 100 is removably attached to the insert groove 160. Removably attached means the at least one cutting insert 100 is secured within the insert groove 160 in a way that allows for unlimited connection, disconnection, and repositioning of the at least one cutting insert 100 within the insert groove 160. Unlike prior art boring bar heads that have integrated cutting inserts permanently attached to the boring bar head, the removeably attached cutting insert 100 can be connected, disconnected, and repositioned within the insert groove 160 to allow for the machining of deep, flat bottomed holes without multiple machining parts. In prior art boring bar heads, when machining a deep, flat bottomed hole, one boring bar head is unable to machine the perimeter and the center of the hole. In the present invention, the cutting insert 100 can be disconnected and repositioned on the same boring bar head to machine the perimeter and the center of the hole. Unlike prior art methods, the cutting insert 100 is not an integrated piece of the front face 144. The at least one cutting insert 100 is removably secured in a way that causes a closed and flat hole to be bored. In an embodiment, one cutting insert 100 is used to bore a deep flat bottomed hole by disconnecting and repositioning the cutting insert 100 in the insert groove 160. In another embodiment, there are two or more cutting inserts 100 removably attached to the insert groove 160 positioned to cause a flat hole to be bored. Therefore, the at least one cutting insert 100 is secured in a way that allows for multiple cutting inserts 100 to be secured within the insert groove 160. In an embodiment, the at least one cutting insert 100 is secured within the insert groove 160 by a dial screw. In another embodiment, the at least one cutting insert 100 is secured by screwing together the cutting insert 100 and the insert groove 160.
The cutting insert 100 has a cutting surface 164 and a bottom surface 166. The cutting surface 164 is the part of the boring head body 142 that actually performs the boring. The cutting insert 100 is any shape that allows the cutting surface 164 to bore long deep holes with flat bottoms. In an embodiment, the cutting insert 100 is rectangular in shape and the cutting surface 164 is spherical. The cutting surface 164 extends to a third length 106. The third length 106 is measured as the distance between the lowest point of the bottom surface 166 and the highest point of the cutting surface 164. In an embodiment, the third length 106 is greater than the first length 112. Alternative embodiments may have other lengths.
While it is not explicitly shown, it is to be appreciated that the cutting insert 100 can be one solid component or it can be comprised of multiple components secured together. If comprised of multiple components, the components would include a cutting surface 164 and a bottom surface 166. For example, in an embodiment, the cutting insert 100 can be comprised of bottom surface 166 that can be secured to different cutting surfaces 164. In an embodiment, the different cutting surfaces 164 accommodate boring different materials with one bottom surface 166. In another embodiment, the different cutting surfaces 164 provide different finishes with one bottom surface 166.
Unlike prior art boring bar heads, the cutting surface of the boring bar head according to the invention can reach the perimeter and the center of a deep hole.
It is to be understood that the above-described arrangements are only illustrative of the application of the principles of the present invention. Numerous modifications and alternative arrangements may be devised by those skilled in the art without departing from the spirit and scope of the present invention and the appended claims are intended to cover such modifications and arrangements.
Any element in a claim that does not explicitly state “means for” performing a specified function, or “step for” performing a specific function, is not to be interpreted as a “means” or “step” clause as specified in 35 U.S.C. § 112, ¶6. In particular, the use of “step of” in the claims herein is not intended to invoke the provisions of 35 U.S.C. § 112, ¶6.
This application is a continuation in part of copending U.S. patent application Ser. No. 15/622,175 filed Jun. 14, 2017.
The United States Government has rights in this invention pursuant to Contract No. DE-AC07-05ID14517 between the U.S. Department of Energy (DOE) and Battelle Energy Alliance LLC.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15622175 | Jun 2017 | US |
| Child | 16181400 | US |
