CA2229724A1 - Slack pulling carriage - Google Patents

Abstract

A slack pulling carriage having a skidding line drum arrangement that achieves efficient and accurate movement of the carriage along the skidding line. The drum arrangement is preferably configured such that the skidding line loops around at least approximately 180 degrees of the circumference of the drum. A hydraulic driving system, a multiple speed motor and locking clamps are also disclosed.

Description

SI~C~ PULLING C~RRIAGE

Inventors: James Q. Carlile, Jr.

FI~LD O~ ~ E IN~N1IO~
The present in~ention relates to slack pulling carriages and more spe~lfi~ally to improving the 0 per~ormance of such carriage~.

BACKGROUND Q~ .T~E lN V ~:N l lON
Slack pulling carriages are generally known in the art. Referring to Fig 1, a di~gram of a slack pulling S carriage 10 in accordance ~i~n the present invention is ~hown. Though Fig. 1 illust~tes a slack pulling carriage incorporating the p~e~ent invention, there are aspect~ of the present sl~ck pulling carriage that are common to all such slac~ p~lling carriages and some of 2 0 the~e aspects are now d~s~s~ed a background tO
facilitate a better understa~d the present in~ention.
A slack pulling carriage generally employ~ a sky line ehat i~ steadfastly mou~ted to a ~ree stump or other mount at a distal end (no~ ~hown) and to a yarder 15 at a 25 landing 25. The carriage 10 mo~es ~reely along the sky line 20 by ~irtue of suitable p~lley arrangements 17. A
clamp 18 is also provided ~or sec~rely holding the carriage at a desired posit~o~ along the sky li~e. A
skidding line 30 feeds th~o~gh a drum arrangement (not ~ LL\C00:'7.OC~

CA 02229724 l998-02-l7 ~hown) ~ithin the carriage and has one end 32 affixed at l~nAin~ 25 and another end 34 which descends from the carriage. End 32 is attached to a mechanical driver for retracting (or letting out the skidding line) and end 34 is the end to which cut logs are attached ~or rel,loval ~rom the forest.
The carriage also includes a clamp (not shown) adjacent the d~um arrangement f~r securely clamping the carriage to ~he skidding line. When this clamp is closed o about the skidding line (an~ che ~ky line clamp is open~, ~..o~e-..e~-t of ~he skidding line ~ause~ the carriage to move along sky line 20. When the skidding line clamp is released (and the sky line cla~p is closed), movement of the ~kidding line causes end 34 to be raised or lowered, hence, ~or example, perlnitting a log to ~e lifted from the forest floor.
Carriage lQ al~o incl~es * mo~or for dr1~ing th~
drum arrangement The combina~iOn of the ~otor and drum arrangement permits mo~ement of ~he carriage along the skidding line (with bo~h clamp~ open). The motor, dru~
arrangement and clamps may be aCtuated by remote control (often using radio frequenc~ c~nt~ol signals).
With respect to prior art slack pulling carriages, these carriages utili~e drum ~rrangements that are disadvantageous for ~ariou~ rèa50ns (discussed below), particularly in view of ~urren~ fores~ practices. For example, there are drum ~rrangements that utilize a plurality of drums wi~h the skidding line threaded intricately through ~he dr~ms. This arrangement pro~ides cM~\~ool-P. ~0l a high degree of ~iction between the carriage and line, which pe~mits sQcu~e mo~effla~t ~f ~he carria~e. This embodiment is disadvantageou~, however, in that (1) it induces an undesirable amount of stress on the skidding s line and drum co~ponent~ and (2) the arrangement is large, relatively expensive, and heavy (requiring more ~tringent skyline anchoring and more energy to move).
Furthermore, this machine ma~ be inappropriately large for curre~t forest practices whi~h are directed to the o harvest o~ second or thi~ growth forest~, which provide considerably smaller logs shan ~irst growth or virgin forests.
Another known slack pulling ~arriage utilizes a more simplified drum arrangement in which a single drum is provided. In this arrang~ement, the skidding line is pOsieioned between the dru~ and t*o sheave~. An actuator causes the ~heaves to contaC~ the skidding line and push the skidding line into contact with a poreion of the drum. A disadvantage of this arrangement, however, is ~hat a drum/skidding line ~egit~n of sufficient leng~h to achieve efficient and ac~ura~ m~ement of the carriage (i.e., no slipping on ~ne line) is not achie~ed~
Slipping on the line may also tend to diRadvantageously accelerate deteriora~ion of th~ line.

SUMMARY oF. T~ t~ENTIoN
Accordingly, it is a~ object of the present invention to provide a S1~Ck pulling carriage that incorpora~es a minimaligti~ ~um arrangement that ~\~0~l ., . 0~, CA 02229724 l998-02-l7 achieve6 sufficient ~kidding line friction for accura~e a~d e~ici~nt m~ e~ f ~e carriag~, It is another object of the present invention to pro~ide a ~lack pulling carriage that incorporates a single ~kidding line drum and is configured such that the skidding line loops around the drum.
~t i~ another object of the presen~ invention to provide a slack pulling carriage that incorporates a hydraulic eng~ne /motor.
o It is another o~jec~ of the presene in~ention to provide a slack pulling ~a~riage that has a multiple speed moter.
It i~ al~o an object ~ the present invention to pro~ide a slack pulling carriage that incorporaees an improved clamping mechanism.
These and related ob; ect~ Of the present invention are achieved by use of a slack pulling carriage as de~cribed herein. Act~in~nt of the advantage~ and features of che invention should be more readily apparent to those skilled in che art, after re~iew of the following more de~ailed desc~iption of the invention taken together with the dra~ings.

BRIE~ DESCRIPT~ 0~ ~E DRAWI~GS
Fig. 1 is a diagram ~f a ~lack pulling carriage in accordance with che present inve~tion and its associated lines.

~ODOI- P . OOI

Fig. 2 is a side ~iew ~with a cover remo~ed~ of a slack pulling carriage in accordance with the present invention.
Fig. 3 is a diagram of a front view of a drum and s ~kidding line arrangement in accordance with the present invention Figs. 4A-4B are a side ~ie~ and a cross-sectional view, respecti~ely, of a skidding line drum in accordance with the present in~ention.
oFig. 5 is a diagram of the hydraulic power system for a slack pulling carri~ge in accordance with the pre~ent in~ention.
Figs. 6A-C are views ill~t~ating aspect6 of a clamp in accordance with the prese~ ention.
Fig. 7 i~ a side ~ie~ of ~ alternati~e embodiment of a drum arrangement in a~o~ance with the present in~ention.
Fig. 8 is a cross-secti~nal ~iew of an alternaeive e~bodiment of a drum arrangemen~ in accordance with the 20present in~en~ion.

DETAILED ~C~PTION
Referring furcher to Pig. l, the carriage 10 preferably includes an engine generally positioned in the 25a~t section o~ the car~iage ~n~ the drum arrangement generally positioned in the fore seccion of the carriage.
A hydraulic dri~e mechanism W~ich permits the drum to be driven by the engine i~ al~o p~o~ided.

~:~IU\O~ ?. 001 Referring to ~ig. 2, a side ~iew of the slack pulling carriage of ~ig. l in accordance with the presen~
in~ention (with a side co~e~ L~n.oved such that the engine and drum arrangement are vigible) is shown~ The manner in which the sky line 20 mount~ ~o pulleys 17 and is feed through clamp 18 is shown. ~he entry of skidding line 30 into and out of the carriage is ~so shown.
In the embodimen~ Stra~ed in Fig. 2, the drum arrangement include~ a ~ingle drum 50 about which is o looped skidding line 30. A~ will be dPmo~trated in more detail below, the skiddi~g lins in the embodiment of Fig.
2 pre~erably loops aroun~ ~he dr~ at least one complete re~olution and then des~en~ o~t the bot~om of ~arriage 10. By looping skid~ing i~h~ 30 aroun~ dru~ 50, ~ufficient friction (e.g., ~u~fi~ient ~kidding line-drum contact area) for efficient ani ~curate l,.ove,l,ent of the carriage relative to tne ~ki~ding line is achie~ed.
Furthermore, thi~ de~ign p~od~ces a m;n;m~l amount of mechanical/physical stress on ~he line or drum and zo achieves a lightweight, ef ~lc~ent, and potentially more af~ordable carriage 10. ~h~ d~ign of carriage 10 is also well suited ~or ha~ve~ing smaller ~econd growth trees.
Skidding line 30 is fed th~ough an input or fair lead shea~e 70 which fun~ionS eo provide low friction po~itioning of skiddi~g line 30 in a desired location.
The skidding line t~en feds ~hro~gh clamp 72 (de~cribed in ~ore detail below) and loop~ ~ound drum 50.

OOCi-V.CO~

Two ten~ion wheels 52, 53 (shown also in Fig~ 4) are bia~ed againse line 30 as it propagate~ around dnlm ~o. The tension wheels ens~re proper positioning of the skidding line relati~e to ~he ~rum and protect against an undesirable overlap of the line.
The tension wheels are mo~nted to an inner tension arm 56 which is pi~otally eo~pled (about pi~ot poin~ 57) to an outer tension arm ~ he outer tension arm is pivotally mounted (about pivO~ point 41) to the car_iage ~rame (generally represented by reference numeral 40) and i~ biased towards drum 50 by tension spring 62 and tension plug 63 that are al~ Co~pled to the frame. It ~hould be recognized that a hy~taulic cylinder may be utilized in place o~ plug 63. Spring 62 biases outer arm 58 toward the drum, which in turn cau~es pivot 57 to exert approximately equal f orcé tnrough inner arm 56 onto the ten~ion wheel~ 52,53~ Plug ~ permits an operator to adjust the amount of tenSion exe~ted by spring 62 on the outer tension arm. Plug 63 al~o permits release of the ten~ion arms 56,58 ~uch th~t ehey may pivot backward~
about point 41 to pro~ide ampl~ ~Om for the threading of skidding line 30 around dr~m S~.
A~ter looping around drum ~, skidding line 30 exi~s carriage 10 at a port 74 ad~acent output fair lead ~hea~es 75,76. The outpu~ ~h~a~r~s ~unction to maintain line 30 in a position generall~ centered within port 74, particularly when the line i~ pulled at dif~erent angles to retrieve a log.

CA~L~ . oo -Drum 50 is pre~erably dri~en by a hydraulic motor 80, though mechanical driving mechanisms are al~o conte~plated. Hydraulic motor 80 prefera~ly drives dru~
50 by a chain 81 which encircles a gear sprocket (not shown) that is mounted about the drum pivot point 51.
M~tor 80 i~ in tu~n d~iven by hydraulic pre~sure generated b~ engine 85. The engine ~ay be any of ~arious models and in one embodim~nt i~ a 20 XP 2 cylinder air cooled diesel of the type made by Lombardini. A
hydraulic pu~p 86 (or pump5 as discussed below) are mounted to the engine PreSSure built up in the pu~p is transferred through a manifold (discussed with reference to Fig. 5) to motor 80 and cl~mp~ 18,72. A battery 84 is also preferably provided ~~r ignition of engine 85 and to power radio 90 (discussed bQlow)~ amongst other known reasons .
operation o~ the car~iag~ 19 preferably achieved by a remote control radio sig~al ~e~ice 90 such as that made by Remote Safety ~ystems of Salem, OR. The radio 90 controls ehe manifold whi~h in turn controls motor and clamp operation Referring ~o Fig. 3, a front view of drum 50, tension wheel 52 and skidding ~ihe 30 (shown in partial cross-Sec~ion) in accordan~e ~ith the present in~ention iS shown. Fig. 3 illustra~es o~e manner of looping line 3~ around drum 50. TensiOn ~h~el 53 is configured to ha~e two radial grooves 54,55 whi~h re~pectively hold the initial and second wrap o~ line 20 against drum 50 in a manner that prevents destr~c~i~e overlap of the initial DOl~i~.DOI

. CA 02229724 1998-02-17 g and Qecond wraps and ~acilitates frictional contact between the line ~nd drum.
Referring to Figs~ 4A-4B, a 6ide and a cross-sectional ~ront ~riew o~ drum 50 in accordance With the present invention are respec~i~rély shown Drum 50 ITtay be constructed in a plurality of ~anners. In a preferred em~o~imen~ strated in ~igs. ~A-4B, the dru~ includes a Shelby tube 42 that is cue t~ an appropriate length and welded within a 3/4-l circ~lar metal plate 43. A ~langed ring 44 is heat sh~unk on~o eir~lar plate 43 and ~astened by bolts 45. Fig. 4A ~l~o illustrates a bearing cover plate 46 fastened by bolt~ 47. The position of tension wheel 53 rela~ive tO flange ring ~4 is shown in Fig. 4B. It should be recog~i2e~ that the size o~ drum 50 and related componentS ~ay ~r~ based on the intended capabilities and size o~ che ~arriage in which they are incorporated.
Re~erring to Fig. 5, a dla~ràm of a hydraulic drive necwork in accordance ~ith ~he present inven~ion is ~hown. First and sec~nd hydraulic pumps 86,87 are mounted to engine 85. The ~utp~t of pu~p 86 i~ fed to t~e ~irst three ports 92-94 a~ ~ four port mani~old 91 ~nd the outpuc of pump 8~ ig ~é~ to the fourth port 95.
The first port 92 provldeS the supply and return hydraulic press~re to Sk~ 11ne tlamp 18, while the second port 93 provides the supply ~n~ ~eturn hydraulic pressure co skidding line clamp 72. ~he third port and fourth por~s 94,95 pro~ide hydrauli~ pressure supply and return to motor 80. The provision of pu~p 87 with its outpu~

C~\O~ !'. 00~

fed through manifold 91 to port 95 and motor 80 e~ectively makes motor 80 a two 6peed motor. The first speed is generated by pressu~e from pump 86 and the second ~peed i~ generate~ by p~e~sure from both pumps 86 s and 87. The supply line of po~ 95 is coupled to that of port 94 by a check ~alue 91 wh~Ch permits one way ~low.
Fluid on each of th~ plu~ality of return line6 is output to tank 78 for s~b~eguent ~ptake by pump~ 86,87.
A plurality of conventional ~ntrol ~alves 77 are o provided (one each) for each o~ t~e ports 92-95.
The supply and re~rn l~es of third port 94 preferably ha~e interconne~t1n~ check val~es 98,99 o~ a kind generally known in ~he art. The pro~ision of the~e ~al~es permit drum 50 to rot~te ~eely (when the skidding ~5 line clamp is open), thereb~ per~itting the skidding line ~o be retracted or let o~ f~o~ the landing while the carriage remains in place. ~hé manifold is preferab1y made of ~n aluminum block th~gh which the appropriate openings are bored.
Referring to ~igE; 6A-6l3, opén and clo~ed ~riews of a clamp 18,72 as it extend~ plane perpendicular to sky line 20 or skid~ing line 30, ~.e., front or back ~iews from the perspecti~e o~ Pig. ~j in accordance with ~he present in~ention are show~. ~ig. 6A illustrates the closed position (also s~ l in ~ig . 2), while Fig. 3 illu~trates the open or released position. Each clamp ha~ a primary pi~ot axiS 71 ~bo~e which symme~ric clamp member~ 73,74 are pivotally m~un~ed. Clamping elements 2,3 are mounted at one end of members 73,74, C~RL\ O O ~ 0 ~

re~pecti~ely, while two stabilizing links 78,79 are pivotally coupled at the other ends. Two sets o~ c~amp mern~ers 73,74 ar~d stabili2i~g linkB 78,79 are pro~ided for eac~ clamp, on the fron~ a~d back sides thereo~. The s clamping elements 2,3 run between the sets of clamp members 73,74 and along line ~0,~0 (as shown in Fig. 2).
Pressure on members 1~,7~ in the direction of arrows A
(~or the released clamp of Fig. ~B), causes the cla~p to mo~e to the closed pO~ition, shown in Fig. 6A. The o pres6ure is pre~erably exer~ed by a longitudinally di~posed hydraulic cylinder ~noc shown, but known) ~hat is powered ~ia manifold 91. ~n the contracted posi~ion (Fig. 6A), the hydrauli~ cyl1h~er preferably pulls the stabilizing links a few deg~e~ ~ast center (toward~ the cla~ping elements) for enh~nce~ ~ocking.
Re~erring to Fig. 6C, a la'ceral view o~ a representative clamping element 2 or 3 is accordance with the presen~ invention iS sho~h~ ~ach clamping elemenS
2,3 preferably includes a car~iage 4, a pad 5 con~igured for mo~rement along a top ~tl2fàce 6 of carriage 4, a plurality o~ recesses 11-14 ~S shown in ~shpd lines, ~houlder bolts 7,8 ~hich h~ld the pad within the carriage, and a bias ~pring 16. Pad 5 and carriage 4 are also shown in Figs 6A-6B~
Each pad 5 is conf igu~ed ~o ha~e a center groove 9 configured ~o receive line 2~,30 and two recesses 11,12.
The deepest part of groo~e 9 ~5 shown in dashed line.
The carriage 4 is ~achine~ or otherwise formed to ha~e two recesses 13,14 which ~lign wi~h recesseS 11,12, C~\oool -P. ~01 ~1 39~d ::~d NOSW~a~ r N3r~315 1~8~891b~ ~~ :ZI 8561~91~Z0 though they are larger, particularly along the direction of ,nov~ Lt o~ t~e pad.
The shoulder bolts 7,8 are mounted ~hrough recesses 13,14 into reces~es 11,12. ~ ~p~ing 16 twith plug 19) is moun~ed ~hrough a hole 21 formed in carriage 4 to bias bolt 7 and thereby pad 5 towards the position ~hown in Fig. 6C (opposite arro~ C).
A clamp 18,72 is preferably positioned about line 20,30 such that the weight o~ ck pulling carriage 10 o (for the sky line~ or the for~e exerted by the line, for example, while the skidding line is ~eing retracted, causes the pad 5 tO move in ~he ~i~ection of arrow C when the clamp is closed abou~ the ~ubj ect line. Since ~he inward surface 6 of carr~age 4 ~-3 sloped gradually upward along the direction of ar~o~ C, the pad(s) 5 are compres~ed about line 20,30 80~ing to ~ecurely lock ~he carriage to the line. This ~ange~e~t provides 6ecure clamping of the line, even i~ the event of a total loss of hy~raulic pressure. When the clarnp i8 released, ~pring 16 biases pad 5 bac~ t~ its original position.
While there are ~enefits ~o eh~ pad arrangement of ~ig.
6~, it should be recognize~l ~hat o~her aspects of the pre~ent invention can be practiCed with a cla~p that does not ha~e moving pads 5.
Re~erring to ~ig. 7, ~ diagram o~ an alternative embodiment of a drum arr~ngement in accordance with the present in~ention is shown. In the embodiment of Fig. 7, the skidding line 130 is fed through input shea~es 170, through clamp 172 and around drive 150 for a revolu~ion L~ . l n l bl 39~d ~d NOSw~a~ r N3~315 10~8~891bS ~~ :ZI 8661J91~Z0 o~ ~ppr~xim~ly 270 deg~ee~ before e~lting through output sheave6 175. The component~ o~ Fig 7 are analogous to the components of Fig. 2. It should be recognized that although only one loop around is shown in Fig. 7, the skidding line could be wrapped multiple time~
around drum 150.
Re~erring to Fig. 8, a diagram of another alternative embodiment o~ ~ drum arrangement in accordance with the present i~vention i~ shown. Fig. 8 0 illustrates a cross-secti~ of a drum ~0 and ten io~
wheel 253 arrangement in ~hi~h the skidding line 230 is wrapped at least two ti~es around drum 250. The components of Fig. 8 are analog~ous to the components of Figs . 3 - 4 .
While the invention has been descri)~ed in connection with specific embodiments thereof, it will be understood that it i~ capable of further modification, and ~his application is intended to co~e~ any variations~ uses, or adapta~ions of the in~entioh f~llowing, in general, the principles of the in~ention ~n~ including ~uch deparcures from the present disclosur~ ~s come within known or custo~ary practice in ~he ~rt to which the invention pertains and as may be applied ~o the essential features hereinbefore set foxth, and as fall wiehin the ~cope of the iIl~rention and the limits of the appended claims.

CAR~\~oo~ - P . ~o~

Sl 39~d ~d Nosw~a~ r N3~315 10~8~891bS ~~:ZI 8661~ql~Z0

Claims (4)

1. A slack pulling carriage, comprising:
a frame;
a sky line clamping assembly;
a skidding line clamping assembly;
a skidding line driving drum; and a drive mechanism that drives said drum;
wherein said skidding line driving drum is configured within said carriage in such a manner that a skidding line is caused to contact at least approximately 180 degrees of the circumference of said driving drum when said drum is driving that skidding line.

2, A slack pulling carriage, comprising:
a frame;
a sky line clamping assembly;
a skidding line clamping assembly;
a skidding line driving drum; and a drive mechanism that drives said drum;
wherein said skidding line driving drum is configured within said carriage such that a skidding line in use therewith loops around the skidding line driving drum, where the term loops means that a line intersects itself from the perspective of a plane in which that line loops.

3. A slack pulling carriage, comprising:
a frame;
a sky line clamping assembly;

a skidding line clamping assembly;
s skidding line driving drum; and a hydraulic drive mechanism having multiple speeds that drives said drum.

4. A slack pulling carriage, comprising:
a frame;
a sky line clamping assembly;
a skidding line clamping assembly;
a skidding line driving drum;
a drive mechanism that drives said drum; and wherein at least one of said assemblies includes a clamp that is capable of locking to a corresponding line.