US1698170A - Cableway-skidding machine - Google Patents

Description

Jan. 8, 1929.

1,698,170 R. P. RAMSEY dABLEwAY SKIDDING MACHINE Filed Aug. 22, 1924 2 Sheets-5heet l I N VEN TOR.

Haber! P Ramsey BY I ATTORNEYS" Jan. 8, 1929. 1,698,170

R. P. RAMSEY cAaLEwAY sxmnme momma Filed Aug. 22, 1924 2 Sheets-Sheet 2 ATTORNEYZS' Patented Jan. 8, 1929.

UNITED ,STATESPATENT oFFica,

ROBERT 1. RAMSEY, 0F DUIJUTH; MINNESOTA, ASSIGNOR TO CLYDE IRON WORKS, OF DULUTH, MINNESOTA, A CORPORATION OF MAINE;

CABLEWAY-SKIDD'ING MACHINE.

Application filed August 22, 1924. S.eria1' .No. 733,486.

In conveying systems known as rableway skidders, such as are employed for example in transporting logs in logging operations and the like, it has long been customary to use a trolley running back and forth on a tight line stretched between two elevated points of support, the log or like article-being hauled up to such trolley and the latter being then hauled in to one end of such tight line. For the purpose of pulling the trolley out, a so-called out-haul cable or line is. re-

quired in addition to the in-haul cable, the

[latter serving the dual purpose of elevating or lifting the log to, the trolley and then pulling the trolley in in the fashion just referred to. A third line or cable is likewise required where the. in-haul cable is employed to perform such dual "function, such third cable being called a slack pulling line since its purpose is to take the slackout of the in-haul cable when the trolley is hauled out and a fresh log is'to be picked'up. For the purpose of operating the aforesaid outhaul, in-haul and slack pulling lines, a suitable engine with corresponding winding drums, one for each line, and known in the trade as a skidding machine, is employed.

In such skidding machines it has furthermore been the practice" for sometime past to provide means for interlocking the in-haul and out-haul drums so that after the log has been raised, it will require no further expenditure of power to sustain the dead weight, power being required merely to pull or haul the log in to the loading station. It will be understood, in other words, that if these drums were not thus intergeared, the out-haul drum would have to be braked and thereby waste energy in amount substantially equal to the load imposed on the in-haul drum by the weight of the article being hauled in. Despite the marked improvement effected in the operation of cableway skiddingsystems by thus inter-gearing the in-haul and outhaul drums, a serious operative difficulty has nevertheless remained. Obviously when the trolley is at the outer endof the span which it covers, the out-haul drum will have on it an amount'of cable equal to the length of the span and this materially increases the effective diameter of saiddrum at which the cable is coiled, while at the stage of operation in question, the in-haul drum will be substantially empty of cable. Onthe contrary, when thetrolley is at'the innervenol of the span, the condition in question will be reversed, the out-haul drum now being nearly empty, while the in-haul drum has w,ound on'it an amount of cable equal to the length of the span which materially increases theellective diameter of such drum at which the in-haul cable is coiled when compared with the empty state of said drum; It will accordingly be seen that the varying amounts of cable on these two drums will vary the diameters at which the out-haul and in-haul lines arevbeing coiled and consequently vary the speed at which the cables or lines are being coiled, even though the engine that operates the drumis running at a uniform speed. The result will be to proper height, whereupon the two drums may be againintergeared and the normal opera tion resumed, only, however, to beinterrupted Y 1 by the recurrence of the condition just described. Atfthe mid-point in the span only will the twodrums payout and wind'in their respective cables at approximately 7 the same rate. On the other hand, in passing over the inner half of the span, the logwill be unduly elevated and j am against the trolley unless the'in-haul drum be stopped and theout-haul line payed out the proper amount. This likewise may have to be done a number of times in the case of a long span, with the result that considerable delay is incurred in hauling in alog and there is of course a waste of power every time the line 1138 to be readjusted.

One principalobj ect of the present invention, accordingly, is to provide a skidding machine in which the in-haul and out-haul lines may at alltimes be intergeared or interlocked together, whatever the length of span covered by the trolley operated by such-machine. Briefly stated, this result is accomplished by providing means for intergearing the drums in question together in difiierent ratios. Asa result,'it is unnecessary to interrupt the operation o't-Lthe machine and being greaterowing to the fact that gear 23 is larger than gear 28 and pinion 22 is smaller than pinion 27. This drum therefore can be rotated in a counter-clockwise direction at two different speeds which may be called high speed and low speed for the purpose of distinction.

Out-haul drum 9 can be rotated at a. cer tain speed in a clockwise direction by thrusting gear 25 thereagainst, and in a counterclockwise direction at a greater speed by thrusting gear 29 against its opposite end, gear 25 being larger than gear 29, and pinion 22, which drives said gear 25 through gear 23, being smaller thanpinion 27. hen it is desired to use slack pulling line drum 15, the brake is held on out-haul drum 9 and gear 30 is thrust into engagement with said drum 15*, as a result of which the latter Will be rotated in a. clockwise direction and pull in the slack pulling line. The effect of pulling in such line will be to cause the outer end of the in-haul line to slack beyond pulley block 12 towards the ground.

By way of general description of the operation of the system, assuming the trolley or carriage 2 to be in the air directly above a. log that is to be skidded, the slack pulling line drum 15" will be operated in the manner just explained to bring the end of the in-haul cable 11 to within reach of the log. It is then suitably fastened thereto by means of the tongs 13 or equivalent device. The out ha-ul line 9 is now held stationary by means of the brake on drum 9 and gear 23 is thrust against the in-haul drum 11 which winds up the inhaul line 11 and causes the log to be raised up toward the trolley or carriage. lVhe-n the log is elevated to the proper height, gear 25 is engaged with the out-haul drum and thebrake on said drum simultaneously released. As a result, the in-haul and out-haul drums will be geared together and the out-haul line will be paid off the drum at the same time that the in-haul line is wound up. As the operation is continued, these two lines are respectivelypaid out and pulled in at certain relative speeds, the speed of the line going out being somewhat greater than that of the line com ing in so that the log will gradually lower away from the carriage.

lVhenever the log becomes sufficiently low so that it is in danger of dragging on the ground, gear 23 is released from the in-haul. drum and gear 28 engaged therewith instead. It will be understood that the standard means provided for thus engaging these gears with the drum, such as the thrust cylinders shown, may be so arranged that the change in question can be made practically instantaneously, that is, the gear 28 will be engaged with the drum the moment gear 23 is released and vice versa. As a result of this lastmentioned shift of gears, the in-haul drum 11 will be rotated at its high speed and thereby wind in the corresponding line faster, the arrangement in fact being such as tocause its line to be thus wound in faster than the out-haul line is going out. As a result the log will gradually rise again as the carriage travels along the tight line, and if this condition were permitted to continue, the log would eventually jam against the carriage. Before this can occur, how-ever, the gear 28 is disengaged from and the gear 23 engaged with the in-haul,

drum-so as to restore the first described eondition. t

It will be seen from the foregoing that a log'suspended from the in-haul line under-the carriage and being brought towards the loadingstation can be raised or lowered at the will of the operator by thus engaging and disengaging the gears in question with the inhaul drum. It will be- -noted further'that the speed of travel of the carriage is controlled entirely bythe rate at which out-haul line 9, which is fastened at its outer end to such carriage, is paid off of drum 9. i The result, therefore, of applying high or low speed drive to in-haul drum 11 is to cause the log to gradually be raised or lowered under the carriage in its travel towards the machine, as just set forth.

lVhile I only show two speeds for the inhaul drum, it will be understood that if for any reason it should be found desirable to increase the number of speed changes in the mechanism for driving this drum, this .may be readily accomplished. With this arrangement the operator is enabled to run his engine at full speed continuously and still control the elevation of the log very easily by simply changing the drive from thein-haul V drum from high to low speed or vice versa, these changes being made instantaneously and without shock to machinery or lines. Furthurmore, the iii-haul and out-haul drums being at all times interlocked or geared together, none of the advantages of the inter geared system arelost nor is there any waste of power involved inv adjusting the elevation of the log by my improved arrangement since the downward movement by correspondingly relieving the load on the in-haul cable will make up for the energy required again to elevate the log.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the mechanism herein disclosed, provided the means stated by any of thefollowing claims or the equivalent of such stated means he employed.

I therefore particularly point out and distinctly claim as my invention 1. The combination with a power driven shaft; two drum-shafts parallel therewith; in-haul and out-haul drums mounted on said drum-shafts, respectively, and normally free- 1y rotatable with respect thereto two gears on each of said drum-shafts, respectively, said gearsbeinglikewise normally freely rotatable and one pair thereof intermeshing; means adapted to fix said gears to the corresponding drums as desired; a pinion fixed on said driveshaft and meshing with the one of. said intermeshing gears corresponding with said inhaul drum; and a second pinion fixed on said drive-shaft and meshing with both of the other pair of said gears, the gear ratios of the respective setsof gears whereby said drums ma thus be rotated by said drive-shaft being difi erent. l

2. The combination with a power driven shaft; two drunrsha'fts parallel therewith; in-haul and out-haul drums mounted on said drum-shafts, respeetivelymnd normally tree ly rotatable. with respect thereto; t 3 ears on each of said drum-shafts, respectively, said gears being likewise normally freely rotatable and one pair thereof intermeshing; means adapted to fix said gears to the corresponding drums as desired; a pinion fixed on said drive-shaft and meshing with the one of said intermeshing gears corresponding with said in-haul drum; anda second pinion fixed on said drive-shaft and meshing with both ofthe other pair of said gears, the gear ratios of such last-mentioned set of gears being such as to rotate said in-haul drum more rapidly relatively to said out-haul drum than said first-,lnentioned set of gears.

3. The combination with a power driven shaft; two drum shatts parallel therewith; in haul and out-haul drums mounted on said druInshat'tS, respectively, and normally free 1y rotatable with respect thereto; two gears on each of said drum-shafts, respectively, said gears being likewise normally freely rotatable and one pair thereof intermeshing;

of the other pairot said gears, the gear ratios.

of the respective sets of gears whereby said drums may thus be rotated by said drive-shaft being ditlerent; a third shaft; a slack pulling line drum normally freely rotatable thereon; and means adapted to intergear said last named druinwith one of said intermeshing pair of gears.

4. The combination with a power driven shaft, two drum-shafts parallel therewith; in-haul and out-hauldrums mounted on said drum-shafts; respectively, and normally freely rotatable with respect thereto; two gears on each of said drum-shafts, respectively, said gen rs bein likewise normally freely rotatable and one pair thereof intermeshiijig; means adapted to, fix said gears to the corresponding drums as desired; a pinion fixed on said drive-shaft and meshing with the oneof said interniieshingi gears corresponding with said in-haul drum; a second pinion fixed on said drive-shaft and meshing with both of the other pair of said gears, the gear ratios of the respeetivesets of gears whereby said drums may thus be rotated by said driveshat-t being diil'erent; a third shaft; a slack pulling line dram normally freely rotatable thereon; and means adapted to intergear said drum with the one of said intermeshing pair of gears corresponding with said in-haul drum.

Signed by inethis 18th day of August,

ROBERT P. RAMSEY.

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