US2720392A - Bit mounting for cutter chains - Google Patents

Description

1955 J. R. CARTLIDGE ,7 0,

BIT MOUNTING FOR CUTTER CHAINS Filed May 18, 1953 INVENTOR. claw/v Cmin was;

QZZWVW ATTORNEYS.

United States Patent BIT MOUNTING FOR CUTTER CHAINS John R. Cartlidge, Cincinnati, Ohio, assignor to The Cincinnati Mine Machinery Company, Cincinnati, Ohio, a corporation of Ohio Application May 18, 1953, Serial No. 355,740

6 Claims. (Cl. 26233) My invention relates to cutter chains and bits such as are employed in mining machinery, and especially to that type of structure wherein various link elements of a traveling cutter chain are provided with sockets which accept the shanks of cutter bits.

The general details of such structures do not require description here, since they are old and well known. The sockets are normally formed as integral parts of the double link elements of cutter chains, which elements are interconnected by single link elements through the agency of suitable pintles. The angularity of the openings in the socket elements which receive the shanks of the cutter bits normally vary from link to link so that successive cutting bits coact to provide a cut of suflicient width to accommodate the driven cutter chain and the arm on which it is mounted.

The mounting of the shanks of cutter bits in the sockets aforesaid presents a serious problem inasmuch as the bit and chain elements are subjected to excessive strain and vibration during the cutting operation. Usually an endeavor is made to hold the bit shank in the socket by means of a set screw which, threaded through one of the walls of the socket, forces the bit shank against an opposite wall. Since it is sometimes desirable to change the direction in which a cutter chain operates, forward and rear walls of the sockets are usually perforated and threaded so that the position of the bit may be reversed as desired.

When, in such a structure, the set screw becomes loosened or worn, the shank of the cutter bit will be released in greater or less degree and when so released is capable of longitudinal movement as well as lateral movement. It has hitherto been understood that longitudinal movement of a cutter bit is highly undesirable, and it has been suggested that such movement could be prevented or minimized by forming a notch in the bit shank and by providing in the socket a member having a detent or tooth to enter the notch. Such a detent or tooth can be formed on the end of the set screw, but this has the elfect of diminishing the area of contact between the set screw nose and the bit shank and increasing, to some extent, the likelihood of the set screw becoming loosened. It has also been suggested that a member having teeth or serrations could be afiixed within the socket to coact with notches or serrations in the bit shank; but the use of such a member, by reason of the room it occupies, requires the use of bits with smaller shanks than could otherwise be accommodated in the same socket.

The fundamental object of my invention is to provide a mode and structure for holding bit shanks in socket members, wherein the above mentioned disadvantages are avoided.

It is an object of my invention to provide a mode and structure for holding bit shanks wherein a detent or detents fixed with respect to the socket engage cooperating serrations in the bit shank, but wherein the cooperating tooth-and-notch engagement does not involve the clamping set screw.

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It is an object of my invention to provide a structure wherein tooth-and-notch engagement is elfected without taking up space inside the socket so as to diminish the otherwise possible cross section of the cutter bit shank.

It is an object of my invention to provide a structure and mode of operation wherein the above advantages may be attained without sacrifice of the ability to reverse the position of the cutter bit and with the further advantage of longitudinal adjustability of the shank in the socket.

These and other objects of the invention which will be set forth hereinafter, or will be apparent to one skilled in the art upon reading these specifications, I accomplish by that structure and arrangement of parts of which I shall now describe an exemplary embodiment. Reference is made to the accompanying drawings wherein:

Figure 1 is an exploded elevation of a threaded plug and toothed insert.

Figure 2 is a partial cross sectional view through the socket of a cutter chain showing a cutter bit in engaged position, the threaded plug being also sectioned to show the coaction of the parts.

Figure 3 is a partial sectional view which is similar to Figure 2 excepting that neither the plug nor the set screw is sectioned.

Referring further to Figure 2, I have there shown in longitudinal section the integral socket element 1 of a double link element of a cutter chain, one of the link cheeks of which is partially shown at 2. The element 1 provides a socket by reason of a perforation or hole 3 of a size to accept the shank 4 of a cutter bit having a head 5. The details of construction of the cutter bit are not a limitation on this invention. The holding of the cutter bit by means of the shank 4 is the thing which is of importance here. Hence, the cutter bit may have an integral head 5 with or without a hard cutting insert, or it may be of more elaborate construction wherein a plurality of parts coact to hold and mount a separate replaceable cutting element.

The socket element 1 has a threaded perforation 6 in a forward or rear Wall and a similar threaded perforation 7 in the opposite wall. These perforations may be used selectively to accommodate a set screw 8 having a nose 9 to engage the bit shank 4 and force it against the opposite interior wall of the socket element. As is well nnderstood in the art the set screw 3 may be employed either in the perforation 6 or in the perforation 7 depending upon which way the bit is oriented in the socket and the direction in which the chain is driven.

The rear edge of the shank 4 is provided preferably with a series of notches, serrations or indentations 10. These are intended to engage with serrations or teeth 11 on a plug element 12 which is to be supported in the socket 1 opposite the set screw 8 in a manner hereinafter to be described. The plug element 12 may have one or more teeth 11; the serrations 10 in the shank 4 are preferably formed as an extended series to provide for adjustability.

The element 12 is preferably made in the form of a tapered plug and is to be held in a correspondingly tapered bore 13 in a threaded plug or set screw 14 designed to be threaded into one of the threaded openings 6 or 7 of the socket member 1 in a position opposite the set screw 3. The tapered bore 13 may be continued as a straight bore 15 through the head of the set screw as shown in order to prevent difficulty with coal dust or other foreign matter in the bore 13; and the threaded shank of the set screw 14 is preferably bifurcated by longitudinal cuts indicated at 16. Thus a force tending to thrust the tapered plug 12 into the tapered bore 13 will tend to spread the bifurcations of the set screw or threaded plug 14.

The set screw 14 when in place as shown in Figures 2 and 3 supports the plug 12 in such position that its teeth 11 may engage in the serrations of the bit shank 4. This may be accomplished without causing the member 12 to take up space inside the perforation 3 of the socket element 1. The position of the plug 12 may be such that rear edge portions of the bit shank 4 may abut the rear interior wall of the socket member 1 and be pressed thereagainst through the action of the set screw 8. This makes for an exceedingly firm clamping of the bit shank while preserving the advantages of detent engagement and adjustment. The ultimate position of the plug 12 may be adjusted by means of the set screw or threaded plug 14, and the threaded plug not only supports the tapered plug 12 but the pressure of the tapered plug in the bore 13 expands the threaded plug, and makes it non-loosening. The tapered plug 12 may be readily inserted into the bore 13 from the inside of the socket. It may also readily be removed from its engagement within the bore 13 by a knockout pin inserted through the bore 15. Thus, should the tapered plug 12 become worn or broken it may easily be replaced. Moreover, the structure is such that the tapered plug and set screw combination is easily installed in either of the threaded openings 6 or 7, or changed from one to the other so that the cutting direction of the chain may be varied at will.

Modifications may be made in my invention without departing from the spirit of it. Having thus described my invention in an exemplary embodiment, what -I claim as new and desire to secure by Letters Patent is:

1. In a cutter chain combination a chain element providing a member for a socket, a cutting element having a shank for entering said socket, said socket element having opposed threaded perforations in its front and rear portions, a set screw engaged in one of said perforations and acting to urge said shank toward the other of said perforations, so as to force said shank against the opposed portion of said socket element, a plug located in the other of said perforations and having a detent, said shank having a notch engaged by said detent, and a set screw threaded in said other of said perforations and acting as an abutment for said plug to hold it in adjusted position without forcing said shank away from said opposed portion of said socket element.

2. The structure claimed in claim 1 wherein the plug engages in an opening in said last mentioned set screw.

3. The structure claimed in claim 1 wherein the plug engages in an opening in said last mentioned set screw, said opening and the plug itself being correspondingly tapered, the said set screw in the area of said opening being split so that the forcing of the said plug into said opening expands said set screw.

4. The structure claimed in claim 3 wherein said last mentioned set screw is perforated throughout its length to facilitate removal of said plug.

5. The structure claimed in claim 4 wherein said shank is provided with a plurality of notches for adjustability.

-6. In a structure of the class described a chain element having a socket member, a cutting element having a shank adapted to enter said socket member, a set screw threaded in said socket member to force the shank against an opposite portionv thereof, aid opposite portion having a threaded opening, a plug having a detent located said threaded opening and engageable with a notch in said shank, and a set screw in said threaded opening for controlling the position of said plug such that its detent will engage in said notch without forcing said shank away from said opposite portion of said socket member.

References Cited in the file of this patent UNITED STATES PATENTS 936,549 Lyndholm 'Oct. 12, 1909 1,045,813 'Carr Dec. 3, 1912 1,310,213 Rixson July 15, 1919 1,777,515 Cartlidge Oct. 7, 1930 2,658,740 Dann NOV. '10, 1953

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