Patent Application
20060279133
The present invention relates, in general, to cutting tools and, more particularly, this invention relates to an improved retaining system for retaining such cutting tools in their support blocks.
Prior to the conception and development of the present invention, cutting tool assemblies have been in widespread use. These cutting tool assemblies are used, typically, in mining, in the surface milling of roads and for clearing debris from undeveloped land. The cutting tool usually carries a hardened work tip for increased tool life and is rotatably mounted into a support block. The support blocks are either bolted or welded onto a drum or other carrier, which in turn is rotatably driven to engage the cutting tools forcibly into whatever material is chosen to be addressed by the machinery.
Each cutting tool is generally secured within the support block with at least one retaining pin engaging complimentary and radially opposed grooves formed in a bore of the support block and in the shank portion of the cutting tool. The axis of the complimentary grooves are disposed transversely to the longitudinal axis of the bore and the shank of the cutting tool. Additionally, such axis are generally parallel to a rotational axis of the drum or other carrier.
To increase performance, it is desirable to have the aforementioned drum equipped with a large quantity of cutting tools disposed in close proximity to each other thus limiting the lateral space between adjacent support blocks. A problem in increasing the quantity of cutting tools is that the resulting limited lateral space between adjacent support blocks increases the difficulty and the effort of removing and replacing retaining pins in order to replace the cutting tool which is, as is generally well known, subject to substantial wear during use.
Therefore, there is a need to provide an improved retaining system for securing a cutting tool within the support block.
The present invention provides a retaining system for securing a cutting tool to a support block which is rigidly attached to an outer surface of a carrier normally having a rotational axis. The retaining system includes a first groove, having a first predetermined shape, formed in an outer surface of a shank portion of such cutting tool. The first groove is formed in a direction generally transverse to a longitudinal axis of the shank portion. There is a second groove, having a second predetermined shape, formed in a surface of a bore formed through an axis of the support block for receiving therein such shank portion of the cutting tool. The second groove formed in the outer surface of such shank portion of the cutting tool is radially opposed to the first groove formed in the surface of such bore formed through the axis of the support block when such shank portion is inserted into the bore of the support block. The second groove has a longitudinal axis aligned substantially perpendicular to such rotational axis of the carrier. The final essential element of the retaining system is a pin member engageable with each of such first groove formed in the outer surface of such shank portion of the cutting tool and the second groove formed in such surface of the bore formed through the axis of the support block for securing the cutting tool to the support block. The alignment of the second groove enables ease of installing and removing the pin member in applications wherein the support blocks are disposed in close lateral proximity to each other and further facilitates use of simple power tools.
It is, therefore, one of the primary objects of the present invention to provide an improved retaining system for affixing a cutting tool to a support block.
Another object of the present invention is to provide an improved retaining system for securing a cutting tool to a support block that allows reduced lateral spacing between adjacent support blocks.
Yet another object of the present invention is to provide an improved retaining system for securing a cutting tool to a support block that allows easy replacement of the cutting tool.
A further object of the present invention is to provide an improved retaining system for securing a cutting tool to a support block that allows use of simple power tools to replace the cutting tool within the support block.
Yet another object of the present invention is to provide an improved retaining system for securing a cutting tool to a support block that is easy to manufacture.
An additional object of the present invention is to provide an improved retaining system for securing a cutting tool to a support block that is easily adaptable to prior art type cutting tools.
In addition to the numerous objects and advantages of the present invention listed above, various other objects and advantages of the invention will become more readily apparent to persons skilled in the relevant art from a reading of the detailed description section of this document. The other objects and advantages will become particularly apparent when the detailed description is considered along with the attached drawings and the appended claims.
Prior to proceeding to a much more detailed description of the present invention, it should be noted that identical components which have identical functions have been identified with identical reference numerals throughout the several views illustrated in the drawing Figures for the sake of clarity and understanding of the invention.
Referring initially to
The cutting tool 20 has at least one groove 22 having a predetermined shape, formed in an outer surface of a shank portion 24, groove 22 being formed in a direction transverse to a longitudinal axis of the shank 24. Preferably, such predetermined shape of the at least one groove 22 is oblong.
When the shank portion 24 is inserted into the bore 18, and the first ledge 28 abuts a face of the support block 30, the groove 22 is radially opposed to the grooves 16a and 16b and complimentarily aligned therewith.
To securely retain the cutting tool 20 within the support block 12, at least one pin member 8, being preferably a pair of pin members 8, are inserted into apertures 19a and 19b and are engageable with groove 22 of shank portion 24 of cutting tool 20 and grooves 16a and 16b formed in surface of the bore 18. Once the pin members 8 are fully inserted into apertures 19a and 19b, through grooves 16a and 16b respectively, and while the shank portion 24 is fully inserted into support block 30, the presence of pin members 8 prevents shank portion 24 from being removed from the bore 18 of the support block 30.
It will be appreciated that an alignment of grooves 16a and 16b, wherein their longitudinal axis 17a and 17b respectively are disposed generally perpendicular to the rotating axis 6 of the drum 2 offers ease of installing and removing pin members 8 in applications wherein the support blocks 30 are disposed in close lateral proximity to each other as generally vertical disposition of apertures 19a and 19b enables unobstructed access to the pin members 8 and facilitates use of simple power tools.
The pin members 8 are formed of at least one of metal, plastic, ceramic or various combinations thereof. More particularly, metal and preferably rolled spring steel pin members 8 are used in the presently preferred embodiment of the invention. Such pin members 8 are slightly compressed when inserted through apertures 19a and 19b and tend to grip the surface of grooves 16a and 16b thereby frictionally securing the retaining pin members 8 within such grooves 16a and 16b. Accordingly, the size of the apertures 19a and 19b and diameter of the grooves 16a and 16b will be slightly less than identical to the diameter of the pin member 8.
It will be appreciated that pin members 8 manufactured from a rolled spring steel offer increased strength and reduction in cost.
Advantageously, groove 22 of shank portion 24 is formed slightly larger than pin members 8 so that the expanded size of pin members 8, although limited in expansion by the slightly smaller size of grooves 16a and 16b, and thereby smaller than the diameter or groove 22, shank portion 24 is allowed to laterally rotate within the bore 18 of support block 30. Such rotation allows for more even wear of the work tip 21 of the cutting tool 20.
As best shown in
In an alternative embodiment of the present invention, the groove 22 of the shank portion 24 may be formed less than a complete circumference of the shank portion 24 or just a partial circumference to allow rotation in both directions but not a complete lateral rotation in one direction or the other.
Although the present invention has been described in terms of a cutting tool 20 having the first ledge 28, the second circumferential groove 26 and a second ledge 32, it will be apparent to those skilled in the art, that the present invention may be applied to other types of cutting tools which have a shank portion 24 of a uniform diameter having the work tip 21 disposed at one end.
Furthermore, different types of pin members 8, for example, spiral or solid type pin members may be utilized for retaining such cutting tool within the support block.
While the present invention has been described by way of a detailed description of a particularly preferred embodiment or embodiments, it will be apparent to those of ordinary skill in the art that various substitutions of equivalents may be affected without departing from the spirit or scope of the invention as set forth in the appended claims.
This application is closely related U.S. Utility patent application Ser. No. 10/733,607 filed on Dec. 11, 2003, to co-pending U.S. Ser. No. ______ entitled “CUTTING TOOL”, filed concurrently herewith. These applications being assigned to the assignee of the present invention and the disclosures of these applications are hereby incorporated by reference thereto.
