US2956792A - Cutting tool holder having a resiliently biased retaining means - Google Patents

Description

Oct. 18, 1960 G. A. YATES cu'rwmc TOOL HOLDER HAVING A RESILIENTLY BIASED RETAINING MEANS Flled May 1 1958 mm as mm mm mm L 8 w ml s 0% m MY A E G R 0 E G 44 47 m L, A; ATTORNEY 2,956,792 Patented Oct. 18, 1960 United States Patent Ofitice v v 1 79 oo'rrmo 'rooL HOLDER HAVING .A mesm- ENTLY BIASED RETAINING MEANS George A. Yates, 3391 N. Broadway, Grove City, Ohio Filed May 1, 1958, SenNo; 732,395 7 Claims. drapes i'nvention relates 'to a tool holder and more particularly to. at'ool holder havingmeans 'to quicklyremove the tool tl'rerefrom. Y

M'echanization in coal mining operations resolves .itself basically to the cutting away or disintegrating of the coal'rsearn by 'aiplur'ality t cutter'bits. The cutter bits may be a part of a continuous beringtty e mining machine that removes the coal bjy boring an elliptical entry into the vein of coal. The cutterbitsmay be 'a part of a drum head type continuous mining machine having a plurality of horizontal endless cutter chains arranged adjacent to each other and driven as a uriit. This type of mining machine chips away the coal as it advances into the vein. The 'bits may also be a partof a single endlesscutter chain that is employed to undercut the. coal in thevein in preparation for. the blasting operation.

, The e'fiieiencybfany of the above mentioned mining machines dependsupon the sharpness of the multitudes ofcutter .bits secured thereon. Continuous research is being carried onto extend the period that a cutter bit canbe efliciently retainedwon the machine. Even with theadvances that have been made, present-day cutter bit-s remain sharp for a relatively short period of time and the continuous mining machine must be shut down and the dull cutter bits removed and replaced with new sharpened bits; The time spent replacing the cutter bits is considered non-productive in that the machine is not in use and coal is not being mined during this inactive period. .Any reduction in the down-time of a continuous mining machine would proportionately increase the tonnage of coal mined withthat particular machine.

The conventional method for securing cutter bits in the present bit holders is by means of :a set screw wedging the bit shank against the side wall :of the shank receiving socket. To loosen and retract the set Screw, ipry out the dull bit, insert the shank of anew, sharpened bit and again advance the set screw to wedge against'the new cutter bit shank is a laborious and time consu ming-operation. This is especially true when the operat'ion m ust be repeated tor each of the mauy'cutter bits carried by a continuous mining machine.

To further complicate the bit securing or Wedging 'op eration and prolong the down-time of the continuous miner, there have been instances reported where the threaded receiving apertures for the set screw have been contaminated and damaged or the set screws have been 2 holder and gathered with the dislodged coal. 'Not only is the efliciency of the mining machine reduced, but special equipment must then be provided to recover the relatively expensive bits, otherwise machinery used in clean ingflthe coal. may be damaged by the metallic cutter bit,

With my new and. improved bit holder, the time required for the bitych'angin'g operation is materially re 'du'ced. In my construction I eliminate the; set screw typeiof shank securing, means and in its stead I employ a securing means that, through a wedging action, urges thefbitishank against the side wall of the tool holder bit socket. Further, I provide an external means to quickly release the shank securing means so that the cutter bit may be easily removed. securing means includes a cylindrical roller bearing surface that permits the shank of anew, sharp' bit to be inserted into the shank socket without externally releasing the bit securing means .My new, improved bit holder not only provides a means to quickly remove the cutter bit therefrom, but also sturdily carries the cutter bit so that it performs itscutting operation in --afpro.per manner. My cu't'ter bit holder is not aifecte'd" or-contarninated by. coal dust and functions equally-well under the severest mining operations. My cutter bit holder is .furt-her'not affected by the vibration of mining machine so that'the loss of cutter bits due to mining machine vibration is materially reduced.

Accordingly, the principal object of this invention is to provide a tool holder having a means to secure a tool shank therein:

Another object of this inventionris to provide a tool holder having a tool securing means-that may be easily released for tool removal.

'Another object of my invention is "to provide a tool holder in which thetool securingmeans does-not .loosen because of .machineyibration. 1

Another object of my invention is to-provide a cutter bit holder in which the tool securing means is notedversely :atfected' by coal dust or fine coal particles.

Still another object of this invention is to provide a tool holder that is rugged and simple in construction,-easy to assemble and operate.

This invention comprises the new and improved eonstruct-ion and combination of parts and their operating relation to each other which will be described more fully herein'aftertand the novelty of which will be particularly pointed out and distinctly claimed.

In' the accompanying drawings, 'to :be taken as part of this specification, I have fully and clearly illustrated my invention in which drawings:

Figure 1 is a top plan view of a'cutter chain link with the cutter hit secured in the bit holder.

cross threaded in the set screw receiving apertures, 'so

machine results in the bits being pulled out of the bit Figure 2 is a view in section taken along the line 2- 2 of Figure l and illustrating my bit securing means section.

:Figure '3 is a fragmentary view in section taken along the :line 3-3 of Figure 2 and illustrating the upper side wall of the bit shank socket.

"Figure 4 is a fragmentary perspective view of my bit holder illustrating in detail the relative position of the bit shank and the bit securing means.

Figure 5 is a perspective view of my bit shank secure ing means removed from the tool hlder.

Figure 6 is an enlarged fragmentary view in section taken substantially along the line 66 of Figure 3 "illustrating the bit securing means chamber extending into the bit shank socket. I

Referring to the drawings and particularly to Figuresfl and 2, there is illustrated a cutter chaih linlc'generaily indicated by the numeral 11) having a link portion "12, "a bit or tool holder 14, :and a cutter bit 16 The "12'' has a pair of :depending parallel portions 18- and 20 aligned pintle receiving apertures 22 therethrough and a body portion 24 with a single pintle aperture 26 there through. The link 12 is adapted to be connected in an endless chain by means of pintles or pins extending through the apertures 22 and 26 in the illustrated link and other overlapping connecting links. The link depending portions 18 and 20 have outwardly extending top flanges 28 and 30 which also form the base for the bit holder 14. Although the bit holder 14 is illustrated as integrally formed with the chain link 12, the bit holder 14 may also be independently formed and secured to the flange portions 28 and 30 as by welding or the like.

The bit holder 14 is of block-like construction and has an upper side wall 32 and a lower side wall 34. As shown in Figure 2, the bit holder side walls 32 and 34 are in converging relation to each other. The bit holder 14 has a front end wall 36, a rear end wall 38 and a top wall 40 (Figure l). Extending longitudinally through the bit holder 14 is a bit shank socket generally designated by the numeral 42. The socket 42 is rectangular in shape and has a top side wall 44, a bottom side wall 46 and end walls 48 and 50. The top and bottom side walls 44 and 46 are clearly illustrated in Figure 2, and end walls 48 and 50 are illustrated by dotted lines in Figure 1. The longitudinal axis of the socket 42 is indicated in Figure 2 by the line A-A that extends substantially parallel to the bit holder bottom side wall 34. The bit shank socket 42 is adapted to receive the rectangular shank of the cutter bit 16. It should be noted that the socket 42 is rectangular in section and the shank of cutter bit 16 is also rectangular in section.

The bit holder 14 has a securing means chamber generally designated by the numeral 52 formed therein. The chamber 52 has a pair of end walls 54 and 56 (Figure 1) which are substantially parallel to the socket end walls 48 and 50. The chamber 52 also has a top wall 58 and a bottom wall 60 (Figure 2). The chamber 52 is in juxtaposition with the socket 42 and has a greater endwise dimension than the socket 42 so that there is formed a pair of bottom rails 62 and 64. The bottom rail 64 is indicated in dotted lines in Figure 2 and is clearly shown in Figure 6. The bottom rails 62 and 64 support the bit securing means. The longitudinal axis of the securing means chamber 52 is indicated by the line B-B in Figure 2. A portion of the chamber 52 extends into the bit shank socket 42 due to the relation of the longitudinal axes of both the bit shank socket 42 and the securing means chamber 52. The portion of chamber 52 that extends into socket 42 is illustrated in Figures 2 and 6.

The bit holder upper side wall 32 has a T-shaped slot 66 which provides a means for inserting both the bit securing means into chamber 52 and also for inserting a wedging tool as will later be described. The slot 66 extends through upper side wall 32 into chamber 52. The slot 66 forms in the bit holder 14 another wall 68 which serves as a fulcrum for a tool to release the bit securing means.

Positioned within the chamber 52 is a bit shank securing means generally indicated by the numeral 70 (Figure which includes a cylindrical roller bearing 72 and a flexible or resilient block 74. This block 74 may be constructed of a rubber material or the like and has a metallic face portion 76 which is arranged to abut the cylinder 72. As illustrated in Figure 2, the bit shank securing means 70 substantially fills the chamber 52 and urges the roller bearing 72 along the rails 62 and 64 into the bit shank socket 42.

The cutter bit 16 has a body portion 78 with a front cutting edge 80 and a rear shoulder portion 82. Extending from the body portion 78 is an enlongated rectangular shank 84. The shank 84 is positioned in the shank socket 42 and urged downwardly therein until the bit shoulder portion 82 abuts the bit holder top wall 40. In this manner the shank portion 84 properly positions the cutter bit 16 in the bit or tool holder 14. The roller bearing 4 72 is urged against one side wall of the bit shank 84 by means of the compressed resilient block 74 and wedging the other side of the bit shank 84 against the socket bottom side wall 46. In this manner the cutter bit 16 is rigidly secured in the bit holder 14.

Operation To remove the cutter bit 16 from the bit holder 14 a tool such as a screw driver or the like is inserted through the T-shaped slot 66 in the bit holder upper side wall 32 between the roller bearing 72 and the chamber top wall 58. The wall 68 formed by the T-shaped slot 66 serves as a fulcrum for the tool blade. Rotation of the tool in a counterclockwise direction as viewed in Figure 2 will further compress the resilient block 74 and move the roller bearing in the chamber 52 away from the chamber top wall 58. Movement of the bearing 72 upwardly along the rails 62 and 64 releases the wedging action of bearing 72 that was formerly exerted against the side wall of bit shank 84. The cutter bit 16 may then be easily removed from the bit holder 14 by simply removing the bit shank 84 from the bit shank socket 42.

To insert the cutter bit 16 in the bit holder 14, the bit shank 84 is inserted in the socket 42. Although the roller bearing 72 is in the portion of chamber 52 that extends into socket 42, pressure on the bit 16 will compress the resilient block 74 and move the roller bearing 72 upwardly along the rails 62 and 64- to provide adequate clearance for the bit shank 84.

As has been described, with my new hit securing means it is a simple, quick operation to remove the bit 16 by simply moving the roller bearing 72 in chamber 52 out of the portion of chamber 52 that extends into the socket 42. This may be accomplished as previously set forth with a screw driver or the like. It is also a very simple procedure to insert a new, sharp cutter bit by simply urging the roller bearing upwardly by a pressure on the cutter bit 16.

Another advantage of my bit securing means 70 is its operability under severe conditions of contamination. Coal dust or fine coal particles in chamber 52 do not materially afiect the releasing operation of my bit securing means. The block 74 of resilient material and the roller 72 substantially fill the chamber 52 so that the collection of coal dust or fine coal particles is highly improbable.

According to the provisions of the patent statutes, I have explained the principal, preferred construction and mode of operation of my invention and have illustrated and described what I now consider to represent its bat embodiment. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

I claim:

1. A cutter bit chain link comprising in combination a chain link, said link having a cutter bit holder extending laterally therefrom, a cutter bit having a body portion and a shank portion, said shank portion being rectangular in section, said cutter bit holder having a body portion with a cutter bit shank receiving socket extending therethrough, said shank socket being rectangular in section and adapted to receive said cutter bit shank portion, said cutter bit holder body portion having a rectangular chamber formed therein in juxtaposition with said socket, said chamber having its longitudinal axis inclined to the longitudinal axis of said socket and a portion of said chamber extending into said socket, a cylindrical tool securing member positioned in said chamber and having its longitudinal axis transverse to the longitudinal axis of said chamber, a flexible rubber block positioned in said chamber in abutting relation with said tool securing memher, said block arranged to urge said tool securing mem her into said chamber portion extending into said socket to thereby urge said cutter bit shank portion against a side wallof said socket and secure said cutter bit in said bit holder, said cutter 'bi-t'ho'lder body portion .having a l'-shaped slot extending into said chamber, one leg of said slot forming an end wall in said cutter bit body portion in overlying relation with said chamber portion extending into said socket, :said slot adapted to provide an opening for positioning said cylindrical .tool securing means and said rubber block in said chamber, said last named end wall adapted to serve as a for a means to movesaid tool securing member in said chamber away from said chamber portion extending into Said socket to thereby release said cutter bit tool shank.-

A tool holder'having a body portion with a shank receiving socket therein, a cutting tool having a rectangular shank portion, said socket being rectangular in section and adapted to receive said cutting tool shank portion, said tool holder body portion having a rectangular chamber formed therein in juxtaposition with said socket, said chamber having its longitudinal axis inclined to the longitudinal axis of said socket and a portion of said chamber extending into said socket, a flexible tool securing means positioned in said chamber and extending into said shank socket to thereby secure said cutting tool shank portion in said socket by urging said cutting tool shank portion against a side wall of said socket, said tool securing means including a flexible block, said tool holder body portion having a slot extending into said chamber, said slot spaced from said chamber portion extending into said socket, said slot providing an opening for positioning said flexible block within said chamber, and said tool holder body portion having access means to said chamber to provide a means to move said flexible tool securing means in said chamber away from said chamber portion extending into said socket to thereby release said cutting tool shank portion.

3. A tool holder having a body portion with a shank receiving socket therein, a cutting tool having a rectangular shank portion, said socket being rectangular in section and adapted to receive said cutting tool shank portion, said tool holder body portion having a rectangular chamber formed therein in juxtaposition with said socket, said chamber having its longitudinal axis inclined to the longitudinal axis of said socket and a portion of said chamber extending into said socket, a flexible tool securing means positioned in said chamber and extending into said shank socket to thereby secure said cutting tool shank portion in said socket by urging said cutting tool shank portion against a side wall of said socket, said tool holder body portion having a T-shaped slot extending into said chamber, one leg of said slot forming an end wall in said tool holder body portion in overlying relation with said chamber portion extending into said socket, said slot adapted to provide an opening for positioning said flexible tool securing means in said chamber, said last named end wall adapted to serve as a fulcrum for a means to move said tool securing means in said chamber away from said chamber portion extending into said socket to thereby release said cutting tool shank portion.

4. A tool holder having a body portion with a shank receiving socket therein, a cutting tool having a rectangular shank portion, said socket being rectangular in section and adapted to receive said cutting tool shank portion, said tool holder body portion having a rectangu lar chamber formed therein in juxtaposition with said socket, said chamber having its longitudinal axis inclined to the longitudinal axis of said socket and a portion of said chamber extending into said socket, a flexible tool securing means positioned in said chamber and extending into said shank socket to thereby secure said cutting tool shank portion in said socket by urging said cutting tool shank against a side wall of said socket, said tool holder body portion having a T-shaped slot formed therein with a vertical leg intersecting a horizontal leg, said slot extending into said chamber with said verticalleg forming, an end wall in said tool holder body'lportion in overlying relation with said chamber ertion extending into said socket, said slot horizontal leg spaced from said chamber portion extending into said socket and providing an opening for positioning. said flexible tool securing means in said chamber, said last named end wall adapted to serve as a fulcrum for a means to move said tool securing means in said chamber away from said chamber portion extending into said socket to thereby release said cutting 'tool shank portion.

' 5. In combination, a cutter bit holder, a cutter bit having' a body portion and a shank portion, said shank poi-- tion being rectangular in section, said 'cutter bit holder having a body portion with a cutter bit shank receiving socket extending therethrough, said shank socket being rectangular in section and adapted to receive said cutter bit shank portion, said cutter bit holder body portion having a rectangular chamber formed therein in juxtaposition with said socket, said chamber having its longitudinal axis inclined to the longitudinal axis of said socket and a portion of said chamber extending into said socket, a cylindrical tool securing member positioned in said chamber and having its longitudinal axis transverse to the longitudinal axis of said chamber, a flexible rubber block positioned in said chamber in abutting relation with said tool securing member, said block arranged to urge said tool securing member into said chamber portion extending into said socket to thereby urge said cutter bit shank portion against a side wall of said socket and secure said cutter bit in said bit holder, said cutter bit holder body portion having a T-shaped slot extending into said chamber, one leg of said slot forming an end wall in said cutter bit body portion in overlying relation with said chamber portion extending into said socket, said slot adapted to provide an opening for positioning said cylindrical tool securing means and said rubber block in said chamber, said last named end wall adapted to serve as a fulcrum for a means to move said tool securing member in said chamber away from said chamber portion extending into said socket to thereby release said cutter bit tool shank.

6. A tool holder having a body portion with a shank receiving socket therein, a cutting tool having a rectangular shank portion, said socket being rectangular in section and adapted to receive said cutting tool shank portion, said tool holder body portion having a rectangular chamber formed therein in juxtaposition with said socket, said rectangular chamber being greater in lateral extent than said shank receiving socket, said chamber having its longitudinal axis inclined to the longitudinal axis of said socket and a portion of said chamber extending into said socket, a flexible tool securing means positioned in said chamber and extending into said shank socket to thereby secure said cutting tool shank portion in said socket by urging said cutting tool shank portion against a side Wall of said socket, said tool securing means including a flexible block and a cylindrical roller member, said tool holder body portion having a slot extending into said chamber, said slot spaced from said chamber portion extending into said socket, said slot providing an opening for positioning said flexible block and said cylindrical roller member within said chamber, and said tool holder body having access means to said chamber to provide a means to move said flexible tool securing means in said chamber away from said chamber portion extending into said socket to thereby release said cutting tool shank portion.

7. A tool holder having a body portion with a shank receiving socket therein, a cutting tool having a rectangular shank portion, said socket being rectangular in section and adapted to receive said cutting tool shank portion, said tool holder body portion having a rectangular chamber formed therein in juxtaposition with said socket, said chamber having its longitudinal axis inclined to the longtudinal axis of said socket and a portion of said chamber extending into said socket, a flexible tool secure 7 ing means positioned in said chamber and extending into said shank socket to thereby secure said cutting tool shank portion in said socket by urging said cutting tool shank portion against a side wall of said socket, said tool securing means including a flexible block and a cylindrical roller member, said tool holder body portion having a slot extending into said chamber, said slot spaced from said chamber portion extending into said socket, said slot providing an opening for positioning said flexible block and said cylindrical roller member within said chamber, and said tool holder body portion having access means to said chamber, said access means permitting access to said chamber portion extending into said socket, said access means arranged to provide a means to move said flexible tool securing means in said chamber away from said chamber portion extending into said socket to thereby release said cutting tool shank portion.

References Cited in the file of this patent UNITED STATES PATENTS 1,325,029 Morgan Dec. 16, 1919 2,089,166 Reichhardt Aug. 3, 1937 2,483,032 Baer Sept. 27, 1949 2,576,225 Hostetter Nov. 27, 1951 2,657,482 Launder et a1. Nov. 3, 1953 2,846,790 Davis et a1. Aug. 12, 1958

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