Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02229724 1998-02-17
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
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~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
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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
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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.
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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.
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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.
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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.
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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
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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~
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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,
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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,
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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
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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~
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