US2094278A - Control mechanism for power shovels - Google Patents

Description

sq, 2a, 1937.

s. e. MORIN ET AL I CONTROL MECHANISM FOR POWER SHOVEL S Filed Nov. 19, 1935 5 Sheets-Sheet 1 INVENTOR 50mm 6 Mon/1v 40m 7 BY [Mas d fimsraav VWML ATTORNEYS Sept. 28 1937. e. s. MORIN ET AL 2,094,273

CONTROL MECHANISM FOR POWER SHOVELS Filed Nov. 19, 1935 3 Sheets-Sheet 2 I I I INVENTOR v 0R6E6 fl/R/A/ 40D MILE 1/. (3 L570 ATTORN YS 's p 1937- G. G. MORIN ET AL 2,094,278

CONTROL MECHANISM FOR POWER SHOVELS Filed Nov. 19, 1935 I s Sheets-Sheet 3 INVENTOR 6/ I 550mm 6: MoR/w A:

BY 54/1511 (imam/v m6 ATTORNEYS Patented Sept. 28, 1937 PATENT OFFICE 2,094.21: con'rnor. suron rowan snovans George G. Morin and smut J. Carleton, Holyoke,

' Mass; said Carleton a-ignor to said Morin Application November 19, 1935, Serial No. 50,554

2' Claim.

This invention relates to excavating machinery of the type of shovels, cranes, and scoops, and has particular reference to improved mechanism for swinging the boom by which the shovel is carried. 5 As will be pointed out below. however, the invention is not in all particulars limited to this use, certain features finding applicability to mechanical means for tripping the door at the bottom of the shovel.

swinging of the boom, particularly with respect to the amount of eflort required of the operator in actuating the controls. Inanother aspect the invention is concerned with, mechanism permitting the boom to be swung rapidly and surely to any desired position and then held firmly while the desired excavation or unloading is being accomplished without the necessity of using the reversing mechanism of the swing in order to bring the boom to rest. As is well imderstood. it is customary to swing the boom by moving not only the boom but the wholecab and operating mechanism as well, giving a considerable weight which it is necessary to bring rapidly to rest when the swing has been completed. For reasons which will appear in detail below the prior practice of using the reversing mechanism for this purpose has entailed a seriously great wear on the parts, which it is one object of the present invention to eliminate. Other objects will appear from the following description and claims.

Referring to the drawings,

Fig. 1 is a transverse sectional view of a'driv ing means for rotating the boom of a power shovel, embo y g the present invention;

Fig. 2 is a side view of the brake mechanism through which movement of the boom in one direction is controlled; 7

Fig 3 is asimilarviewof the brake mechanism which holds the boom when the control shaft is in neutral position;

Fig. 4 is a view on a smaller scale showingthe general assembly of the steam shovel and con- 45 trolled parts;

- Fig. 5 isa-transverse sectional view oi'adipper tripping mechanism embodyingthe present inventlon; T

Fig. 6 is a fragmentary-side view of the clutch 5o actuating cams;

Fig. Us a sectional view on line I-'-I-of showing the clutch actuating camsln operative position;

vievg'similar-tol'ig. showing the 'Fig; 8 is a 55 parts in clutch operating position;

In one aspect the invention is concerned with giving a better control over-the- Fla- . Fig. 9 is an end view of the control cam shaft showing the relative position of the several control cams; and

Fig. 10 and Fig. 11 are views similar to Fig. '1, but showing two alternative forms of interen- 5 aging cams. V

Referring toFlg. 4, a. conventional power shovel is shown comprising a caterpillar carriage I, upon which is rotatably mounted a. cab 2 in which the engine and driving mechanism is mounted. The boom pivoted at its lower end to the cab is indicated at 3 and carries a dipper 4 and dipper stick 5, the latter retractably and pivotally mounted on the boom.

The cab is pivoted on the carriage at 6 and is rotated about said pivot through a stub shaft l0 journaled inthe cab frame and provided at its lower end with a pinion meshing with a gear l2 also carried by the cab. A planetary pinion l3 secured to gear l2 engages an internal gear I! fixed to carriage concentrically with pivot 5 whereby rotation of shaft i0 causes pinion l3 to travel around gear I! thus turning. the cab and the parts carried thereby about pivot 6 in a direction determined by the direction of rotation of shaft I8. This mounting of the cab on the carriage is conventional and need not further be described.

Referring now'to Fig. 1, the upper end of stub shaft i0, is shown provided with a bevel gear .8 engaging diametrically opposed bevel pinions l5 and i5 freely mounted on a power shaft l6 which is normally constantly rotating and serves as the source of power to drive shaft ill in either direction depending on which of pinions l5 or N is coupled to power shaft l6. Bushings and I1 are interposed betweenthe pinions and the shaft. As is obvious from Fig.1: pinions l5 and I5, and the parts associated therewith are similar but reversed and similar parts are given the same reference characters except that the characters to'the right as viewed in Fig. 1 are primed. Adescrlption of the parts associated with pinion l5 will serve equally for the parts associated with pinion l5.

Pinion Ii isformedwith a flange |8't o which an annular member "is secured by bolts 20. An annular disc 2| forming one member of. a friction clutch by which pinion i5 is coupled to shaft i6 is mounted on bolts 22 threaded into member II, the annular member 2| having a slight amount'of free play axially of the bolts. Disc 2| extends between opposed clutch members 24? and 25, thefaces of disc 2| being provided with annular friction members 26 secured to disc 2| by rivets 21.

Clutch member 24 is formed integrally with a hub 29 splined at 39 to shaft l6, and positioned between a collar 3| fitting in a groove 32 formed in the shaft and a thrust bearing 33 interposed between the hub and pinion l5. Clutch member 25 is formed with a hub portion 35 rotatably and slidably mounted on hub 29. Members 24 and 25 are connected by pins 36 secured in bosses 31 formed in member 24 whereby both members 24 and 25 constantly rotate with shaft "5, member 25 sliding on hub 29 and pins 36 to frictionally engage disc 2| between the clutch members to thereby couple pinion l5 to shaft |6.

The means for forcing the member 25 toward 24 to engage the clutch comprises two ring members 49 and 4| fitted on hub 29. Member 40 is pinned to hub 35 as at 42. Member 4| is rotatably mounted on the hub 29 but normally partakes of the rotation of ring 49 by engagement of reentrant cam surfaces 44 and 45 formed in rings 40 and 4| respectively, see Fig. '7. As shown in Fig. 1, hub 35 is undercut at 46 to accommodate cam 44. A nut 41 threaded on hub 29 restrains outward axial movement of the rings. It will be obvious that if a s ufiicient drag is placed upon ring 4| to restrain its tendency to move with ring 40, cam 44 will advance relative to cam 45 as shown in Fig. 8, and since ring 4| is held against outward movement by nut 41, ring 4|| and member 25 to which it is attached are moved inwardly as cam 44 advances along the incline of cam 45, thus engaging clutch member 2| between members 24 and 25 and coupling pinion |5 to the power shaft.

Alternative forms of interengaging cams are shown-in Figs. 10 and 11. In the form shown in Fig. 10, earns 44 and 45 are replaced by opposed concave and convex cam members H6 and Ill forming an enclosure for a free cylinder or ball H2. As will be clear, relative movement between ring members 4|) and 4| will cause free member 2 to engage the inclined surfaces of members 0 and ill to separate the ring members, thus engaging the clutch as previously described. The form shown in Fig. 11 is similar in operation, the cam members 4 and H5 in that figure taking the form of elongated curved depressions presenting curved cam surfaces against which a free cylinder or ball 6 operates in the same manner as member ||2in Fig. 10.

To impose the desired drag on ring 4| the latter is provided with a brake drum' 59, secured to the ring by rivets 5|, against which drum brake shoes 52 (see Fig. 2) operate. Shoes 52 are pivoted at 53 to operating arms 54. Links 55, also pivoted to .the shoes at 53 are pivotally connected at 56 to a stationary frame member 51. The operating arms 54 are connected together by a link 59. Separation of the upper ends of arms 54 to move shoes 52 into contact with the drum 50 is effected by a generally diamond-shaped control cam 60 secured on a rock shaft 6|. As previously indicated the pinionsl5 and 'l5' and their respective associated parts are mirror images of each other. It should further be noted (see Fig. 9) that control cam 60' is positioned on shaft 6| at anangle with respect to cam 60, so that rotation of shaft 6| to cause application of shoes 52 to drum 50 by cam 66, simultaneously moves cam 60' out of operating relation to arms 54'. Thus shaft may be caused to rotate in the desired direction by rocking shaft 6| to apply appropriate brake 21 or 21'.

Rock shaft 6| is provided with a hand lever 62 or other suitable operating means. Dependent on the extent to which the shaft 6| is rocked a greater or less force will be applied to brake drums 21 or 21' and a correspondingly greater or less degree of slippage between clutch members 51 and 24-25 (or 51 and 24-25') will take place, thus regulating the speed with which cab 2 and boom 3 are rotated.

As will be clear from Fig. 9, the angle between cams 60 and 60' is such that shaft 6| can be moved to a neutral position in which neither cam is operative to actuate the breaking mechanism and that in this position neither pinion l5 or 15' is coupled to shaft IS, the cam and boom being stationary. For proper operation of the shovel it is desirable that the cab be positively held in its stationary or working position. To accomplish this we provide means to hold one of the pinions |5 or l5 against rotation when shaft 6| is in neutral position. As shown, annular member I9 is provided at its outer periphery with a facing of friction material 65 against which is positioned a brake band 66. The ends of brake band 66 are pivotally connected at 61 to operating arms 68. Arms 68 are respectively pivoted at 69 to parallel links 19 which are pivotally secured at 1| to frame member 51. Pivots 69 are adjustably connected by a turnbuckle 12. The free ends of arms 68 are provided with flanged rollers 15 engaging a control cam 16 secured to shaft 6| and so arranged with respect to cams 6|! and 6| that its operative position corresponds to the common neutral position of the latter cams. It will thus be seen that when shaft 6| is moved to neutral position upon the completion of a movement of the cab and boom in response to either cam 6|! or 6|, cam 16 acts to apply brake 66 thus bringing thecab and boom to rest without use of the reversing mechanism and 'that brake 66 holds. the boom in the position to which it is moved. Since normally a positive brake action is desired in neutral position cam 16 is provided with recesses 11 in which rolls 15 may seat. Cam surfaces 18 however preferably begin to act before cams 60 or 60"are completely released so that the movement of the boom is always controlled and overrun is prevented.

In order to increase the efliciency of the brake 66 we prefer to make it self-energizing in bothcounterclockwise in Fig. 3, the band 66, when the brake is applied, tends to follow the surface of the drum as the band tightens. Such tendency is restrained at the left hand pin 64 (as viewedin Fig. 3) since that pin is in engagement with what is then the rear end of its slot. The other end of the band however is free to advance from its pin with the result that the brake band tends to wrap itself around the drum due to the motion of the drum. When the drum is to be brought to a stop from a clockwise direction of rotation as viewed in Fig. 3, the action is exactly similar except that the function of the two pins and their slots is reversed.

The control mechanism of this invention may be employed to actuate the dipper trip of the shovel or the tag line of a clam shell bucket if the latter is used. In Fig. 4 the boom is shown equipped with a dipper but the dipper trip cable shown at 19 might for illustrative purposes equally well be the tag line of a clam shell bucket.

In either case tension is placed or maintained 5 on cable 19 by winding it on a drum 88, see

Fig. 5. As shown drum 8! is freely mounted by means of roller bearings 8i on a stub shaft 82 secured to the end of constantly rotating power shaft 63, which may be shaft ll previously de- 10 scribed. An annular clutch member 8|, similar to member 2| previously described, is secured to drum 80 at 85 to extend radially inwardly between clutch members 86 and 81 similar in arrangement and construction tomembers 24 and 25. Member 86 is formed with a hub portion 88,

splined at 89 to shaft '82, member 81 being slidably mounted on hub 88 and pinned to member 86 by means of pins 88 for rotation with and movement toward and from the latter member to thereby couple drum 88 to shaft 82. The means for actuating the clutch member 81 comprises a pair of cam rings SI and 82 similar to rings 4|! and ll. Rings 9i and 92 are respectively provided with normally interengaging cam surfaces 83 and.

9.4.. Ring 9! is secured to member 81 by rivets or bolts 95 and ring 82 is riveted at 81 to a brake drum 98. Thus any drag placed on drum 88' causes ring 8! to advance with respect to ring 82 causing cam surface to act; as illustrated in Fig. 8 with respect to rings 48 and ll, to move clutch member 81 into engaging position. The

clutch parts are held in assembled relation by:a

nut I80 threaded on hub 88, a coil spring ill being positioned between nut liiiltand ring Ii vto maintain sumcient pressure on the clutch menbers so that no slack forms in the trip cable or tag line connected to drum II.- r

. Drag is applied to drum 88 for actuation of the clutch by brake means indicated at in whichmeans may be exactly similar. to that employed with drum 5' and therefore needs no further description.

We claim:

1. Means for controlling the rotation of a power shovel cab on its carriage which comprises, a

shaft for rotating the cab, a bevel gear on said shaft, a constantly driven power shaft, two bevel pinions freely rotatable on the power shaftand engaging the bevel gear on opposite sides ofsaid I cab rotating shaft, a friction clutch member connected with each bevel pinion, friction clutch members secured to the power shaft and respectively engageable with the int mentioned clutch members for coupling said pinions to the power shaft, a pair of interntting cam members associated with the power member of each clutch and normally rotatable therewith, one of said cam members being secured to said power member, the second cam member normally rotating with 5 the first cam member by its interengagement therewith and brake means operating on the second cam member to cause relative angular displacement between the cam members to effect engagement of the associated clutch members, 10 the degree of engagement of the clutch members varying with the force of the application of the brake, a rock shaft, a cam on said shaft for actuating one of said clutch actuating brakes when the rock shaft is rocked in one direction, and a 15 cam on said shaft to actuate the other said clutch actuating brake when the rock shaft is rocked in the opposite direction.

2. Means for controlling the rotation of a p wer shovel cab on its carriage which comprises, 20 a shaft for rotating the cab, a bevel gear on said shaft, a constantly driven power shaft, two bevel pinions freely rotatable on the power shaft and engaging the bevel gear on opposite sides of said cab rotating shaft, a friction clutch mem- 25 her connected with each bevel pinion, friction clutch members secured to the power shaft and respectively engageable with the first mentioned clutch members for coupling said pinions to the power shaft, a pair of interfltting cam members associated with the power member of each clutch and normally rotatable therewith, one of said cam members being secured to said power memher, the second cam member normally rotating with the first cam member by its interengagement therewith, and brake means operating on the second cam member to cause relative angular displacement between the cam members to eifect engagement-of the associated clutch members, the degree of engagement of the clutch members 40 varying with the force of the application of the brake, brake means acting directly on one of said pinions to lock the cab against rotation, a rock shaft, a .cam on said shaft for actuating one of said clutch actuating brakes when the rock shaft is rocked in one direction, a cam on said shaft to actuate the other said clutch actuating brake when the rock shaft is rocked in the opposite direction, and a cam on said rock shaft to actuate the cab locking brake when said rock shaft is in neutral position.

' GEORGE G. MORIN.

EMILE J. CARLE'I'ON.

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