US1615526A - Brake-operating mechanism - Google Patents

Description

Jan. 25, 1927.

J C. SMITH BRAKE OPERATING MECH ANISM Filed March 2. 1926 Jwuentoc Patented Jan. 25, 1927.

UNITE STATES J "CLIFFORD SMITH, OF BELLE-LOWER, CALIFORNIA.

BRAKE-OPERATING MECHANISM.

Application filed' March 2, 1926.

'* anisms.

In well drilling rigs, the calf wheel is driven by an engine and is employed for lowering and raising tools in the well. These calf wheelsare controlled by a band brake operated-from a lever and often, due

to sudden reversal of the engine, an unexpected engagement of the clutch or a sudden releasing of the weight which supported from the calf wheel, this lever will suddenly shift with the result that a workman is many times injured thereby. The probability of such injury occurring will be realized when it is noted that it is necessary to have a workman in constant attendance upon the lever during drilling operations.

A further object of the invention is to produce a device of this character which may be applied to the operating levers of calf wheel brakes which are now in position upon the rig.

A further object of the invention is to provide adjustable means for controlling the position of the calf wheel brake with rela-- tion to the rimof the calf wheel.

These and other objects I attain by the construction shown in the accompanying drawings, wherein for the purpose of illustration is shown a preferred embodiment of my invention and'wherein Figure 1 is a side elevation showing brake operating mechanism constructed in accordance with my invention, the control pawl being indicated in normal position by solid lines;

Figure 2 is a plan view of the brake operating mechanism detached;

Figure 3 is a sectional view showing the manner of connecting the cable with the brake lever.

Referring now more particularly to the drawings, the numeral generally designates the calf wheel of well drilling apparatus, the calf wheel being rotatably mounted and having secured thereto the usual drum 11 upon which the tool cable 12 is wound. The numeral 13 generally designates a flexible brake band co-operating with the rim of the calf wheel and having one end thereof secured to a rigid support 14 while the opposite end thereof is secured to the crank 15 of a crank shaft 16 mounted in suitable is applied thereto.

Serial No. 91.785.

bearings 17 upon the support 1 1 or upon the floor of the derrick. One end of this shaft has rigidly secured'thereto an operating lever 18. The crank shaft 16 and lever 18 are usuallly produced from a single bar of round metal bent in the proper form. It will be obvious that by oscillating the lever 18, the band 13 may be engaged with or disengaged from the periphery of the calf wheel.

In order to limit the separation of the brake band 13 from the periphery of the drum, I provide a limiting element consisting of a rod or cable 19 rigidly securedat one end to a suitable support 20 which passes about and is substantially co-extensive with the band 13. The opposite end of the limiting element 191s adjustably secured, as at 21, to a support 22 arising from the floor of the derrick. By adjusting this limiting band, the space between adjacent faces of the calf wheel and band may be at all times maintained uniform,- regardless of wear to which the band 13 is subjected. The connection of the brake band 18 with the crank is preferably likewise made adjustable so that any extreme slack occurring in the brake band may be removed and accordingly the necessary movement of the lever 18 to apply the band kept within certain limits.

In accordance with my invention, 1 further provide an operating mechanism for the band including a shaft 24 mounted in suitable bearings 25 and 26 arising from the floor of the derrick. Between the bearings 25 and 26 a drum 2'? is secured to the shaft and at one end of the shaft a hand wheel 28 Adjacent the hand. wheel, the shaft is formed with a ratchet29 and the adjacent bearing 25 has pivoted thereto a dog 30 for coaction with the ratchet. This dog is connected by a link 31 with a foot treadle 32, the connections and construction of the various parts being such that the dog normally assumes an inoperative position but may be engaged with the ratchet by application of pressure to the foot treadle. A cable or the like is wound several times about the drum and is trained about a pulley or pulleys 83 and between the ends of the cable is inserted a sleeve 34 which slidably embraces the lever 18 intermediate the ends thereof and adjacent its free end.

In the use of the device, when it is desired to apply the brake, the hand wheel is rotated to the left. This forces the lever 18 downwardly through the sleeve 34- in the direction of the arrow with the result that the brake band is tightened upon the periphery of the calf wheel. hen the brake band has been tightened, the pawl may be engaged with the ratchet by placing the foot upon the foot treadle and after the pawl is engaged, the tendency of the brake to release will keep a constant strain of the ratchet teeth against the pawl so that this engagement is maintained. Any tendency of the lever to kick will be frustrated by the engagement of the sleeve therewith and the operator is enabled to leave the lever to assist in other work about the derrick. When it is desired to release the lever, the wheel is rotated in a direztion to tighten the same for a suliicient distance to release the pawl which moves to its inoperative position, thus permitting the wheel to be reversed and the brake to be released.

It will, of course, be obvious that the construction hereinbefore set forth is capable of a certain range of change and modification without materially departing from the spirit of the invention and I accordingly do not limit myself to such specific structure except as hereinafter claimed.

I claim z- 1. In combination, a calf wheel brake band and an operating lever for shifting the same, a drum, a cable wound upon the drum and trained through a suitable pulley, a sleeve with opposite sides of which the ends of the cable connect, said sleeve slidably embracing the lever and means for locking the drum against rotation in a direction per mitting movement of the lever to release the band.

2. In combination, a calf wheel brake hand and an operating lever for shifting the same, a drum, a cable wound upon the drum and trained through a suitable pulley, a sleeve with which the ends of the cable connect slidably embracing the lever and means for locking the drum against rotation in a direction permitting movement of the lever to release the band, said means being normally inoperative and upon a predetermined operation of the drum releasing the drum to permit rotation thereof in a direction releasing the lever.

3. In combination, a calf wheel brake band and an operating lever for shifting the same, a drum, a cable wound upon the drum and trained through a suitable pulley, a sleeve with which the ends of the cable connect slidably embracing the lever, a ratchet associated with the drum, a normally inoperative pawl for engaging the ratchet to prevent rotation of the drum in a direction permitting movement of the lever to release the band and means for shifting said pawl into engagement with the ratchet.

4. In combination, a calf wheel. a brake band therefor and an operating lever for shifting the brake band, a drum a cable wound upon the drum connections between opposite ends of the cable and opposite sides of the operating lever for shifting the operating lever in opposite directions and means for rotating the drum.

5. In con'ibination, a calf wheel, a brake band therefor and an operating lever for shifting the brake band, a drum, a cable wound upon the drum, connections between opposite ends of the cable and opposite sides of the operating lever for shifting the operating lever in opposite directions and means for locking the drum against rotation in a direction permitting movement of the lever to release the band.

6, In combination, a calf wheel, a brake band therefor, an operating lever for the brake band swinging in a given plane, a sleeve slidably engaging the lever, means connected with the sleeve for positively shifting the sleeve in opposite directions to thereby operate the brake lever, said means including a rotatable operator actuated element remote from the plane of swing of the lever and means for locking the first named means against movement in one direction.

In testimony whereof I hereunto atlix my signature.

J CLll FORl) SMITH.

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