US3768853A

US3768853A - Single line log grapple

Info

Publication number: US3768853A
Application number: US00627484A
Authority: US
Inventors: D Rennie
Original assignee: Skagit Corp
Current assignee: DELTA RESOURCES INCORPORATED A CORP OF WA; Skagit Corp; Oil States Industries Inc
Priority date: 1967-03-31
Filing date: 1967-03-31
Publication date: 1973-10-30
Anticipated expiration: 1990-10-30

Abstract

A grapple mechanism is disclosed including a housing suspended from a load line, a pair of pivotally connected load-engaging arms attached to the housing, a lift mechanism associated with the housing including a cycling mechanism which controls the pivot position of the load-engaging arms such that, upon successive applications of a lifting force from the load line, the load arms are alternately held open or closed around a log or similar structure to be lifted. The upper ends of the load arms are connected through links to a link pivot, and the cycling mechanism operates to vary the distance between the link and arm pivots whereby increasing the distance causes the arm sections to move toward each other to close the grapple and decreasing the distance pivots the arms away from each other to open the grapple. Three embodiments disclose somewhat different mechanisms for accomplishing the cycling operation, two being latching devices and the third using a rotatable cam structure.

Description

United States Patent 1 1 Rennie 1 SINGLE LINE LOG GRAPPLE [75] Inventor: David G. Rennie, Burnaby, British Columbia, Canada [73] Assignee: Skagit Corporation, Sedro Woolley,

Wash.

[22] Filed: Mar. 31, 1967 [21] Appl. No.: 627,484 7 [52] U.S. Cl. ..'294/ll0 Primary Examiner1-1arvey C. l-lornsby Att0meySeed, Berry and Dowrey [m 3,768,853 1 Oct. 30, 1973 [57] ABSTRACT A grapple mechanism is disclosed including a housing suspended from a load line, a pair of pivotally connected load-engaging arms attached to the housing, a lift mechanism associated with the housing including a cycling mechanism which controls the pivot position of the load-engaging arms such that, upon successive applications of a lifting force from the load line, the load arms are alternately held open or closed around a log or similar structure to be lifted. The upper ends of the load arms are connected through links to a link pivot, and the cycling mechanism operates to vary the distance between the link and arm pivots whereby increasing the distance causes the arm sections to move toward each other to close the grapple and decreasing the distancepivots the arms'away from each other to open the grapple. Three embodiments disclose somewhat different mechanisms for accomplishing the cycling operation, two being latching devices and the third using a rotatable cam structure.

18 Claims, 17 Drawing Figures Patented Oct. 30, 1973 7' Sheets-Sheet 1 DAVID G. RENNIE INVENT R.

ATTORNEYS Patented Oct. 30, 1973 3,768,853

7 Sheets-Sheet 2 DAVID e. RENNIE I000 INVENTOR.

Patented Oct. 30, 1973 7 Sheets-Sheet L5 N2 M9 NB DAVID G. RENNIE INVENTOR.

ATTORNEYS Patented Oct. 30, 1973 7 Sheets-Sheet 5 2 6 r w 9 0m 2 DAVID G. RENNIE INVENTOR.

ATTORNEYS Patented 0a. 30, 1973 3,768,853

7 Sheets-Sheet 7 DAVID' e. RENNIE INVENTOR.

ATTORNEYS SINGLE LINE LOG GRAPPLE This invention relates to log grapples of the type known as single line log grapples wherein a load line suspends a pair of grapple arms through an actuating mechanism, and wherein the actuating mechanism operates, upon slacking off on the load line, to permit the grapple arms either to be opened to release a log and maintained in an open condition, or to be closed on a log and maintained in a'closed log-gripping conditon when the load line is tightened.

In brief, the invention comprises a pair of pivotally interconnected grapple arms and a grapple arm lifting and actuating mechanism interconnected with the grapple arms. The lifting and actuating mechanism comprises a lifting section adapted to be connected to and suspended from a load line, and a coupler section interconnected to the grapple arms in a manner such that the grapple arms will closed about a log and ramain closed when the load line is tensioned and the mechanism raised with the lifting and coupler sections coupled or interconnected. The mechanism also comprises means interconnecting the lifting section and the grapple arms in a manner such that the grapple arms will be opened from a log-gripping condition and remain open when the load line is tensioned and the mechanism raised with the lifting and coupler sections uncoupled or disengaged.

In the drawings:

FIG. 1 is an elevation view in partial cross section of a grapple arm actuating and lifting mechanism suspended from a load line and suspending a pair of grapple arms in a jaw open condition;

FIG. 2 is an elevation view in partial cross-section of the FIG. 1 mechanism suspended from a load line and suspending the grapple arms in a jaw closed condition;

FIG. 3 is a smaller scale full elevation view of the FIGS. 1-2 embodiment with the grapple arms suspended in a jaw open" condition;

FIG. 4 is a smaller scale full elevation view of the FIGS. 1-2 embodiment with the grapple arms suspended in a jaw closed condition;

FIG. 5 is a cross-section view taken along the line 5-5 of FIG. 1;

FIG. 6 is a cross-section view taken along the line 6-6 of FIG. 1;

FIG. 7 is a cross-section view taken along the line 77 of FIG. 1;

FIG. 8 is an elevation view in partial cross-section of another grapple arm actuating and lifting mechanism as it would appear with the system setting on a log with a pair of grapple arms in a jaw open condition;

FIG. 9 is an elevation view in partial cross-section of the FIG. 8 mechanism suspended from a load line and suspending the grapple arms in a jaw closed condition;

FIG. 10 is a cross-section view taken along the line l0-l0 of FIG. 9;

FIG. 11 is a smaller scale full elevation view of the FIGS. 8 and 9 embodiment with the grapple arms suspended in a jaw closed condition;

FIG. 12 is an elevation view in partial cross-section of the FIGS. 8 and 9 mechanism suspended from a load line and suspending the grapple arms in a jaw open" condition;

FIG. 13 is a smaller scale full elevation view of the FIGS. 8, 9 and 11 embodiment with the grapple arms suspended in a jaw open condition;

FIG. 14 is an elevation view in partial cross-section of a third grapple arm actuating and lifting mechanism suspended from a load line and suspending a pair of grapple arms in a jaw closed condition;

FIG. 15 is a cross section taken along the line 15-15 of FIG. 14;

FIG. 16 is a smaller scale full elevation view of the FIG. 14 embodiment with the grapple arms suspended in a jaw closed condition.

The three exemplary single line grapples shown in the Figures each comprise a pair of load lifting arms 100, 200200 and 300300, respectively. The arms of each pair are crossed and pivotally interconnected near the upper ends thereof for rotation about an

arm pivot

110, 210 and 310, respectively. The lower arm sections of each pair are formed to provide the pincer-like arcuate jaw sections (or legs) l00a-l00a, 200a-200a, 300a300a, respectively with

inwardlydirected gripping teeth

102, 202 and 302, respectively, typical of grapples. The upper arm actuating sections 100b100b, 200b-200b, '300b300b, respectively, are connected to a'

link pivot

104, 204, 304, respectively, by means of equi-length links 106-108, 206-208 and 306-308, respectively, that are pivotally connected to the respective link pivot and to one of the two respective actuating arm sections. By this arrangement, increasing the distance between the respective link and arm pivots will effect pivoting of the respective jaw sections toward one another to close the grapple jaw about an object to be lifted. Contrarywise, decreasing the distance between the respective link and arm pivots will effect pivoting of the respective jaw sections away from one another to open the grapple jaw.

Although other grapple arm arrangements may be applied to this invention whereby the above-described scissors-like action of the jaw sections can be effected, the provision of a link pivot aligned with the arm pivot is preferred for the purpose of this invention because of the more compact structure of the grapple arm actuating and lifting mechanism that can be achieved thereby.

Each of the three embodiments shown in the drawings has a different grapple arm actuating and

lifting mechanism

120, 220 and 320, respectively, for accomplishing the opening and closing of the respective grapple anns.

The

mechanisms

120, 220 and 320 each comprise a coupler section pivotally interconnected with the grapple upper arm sections, a lifting section adapted (i) for attachment to the load line and (ii) to move longitudinally relative to the coupler section to interlock with the coupler section to permit the grapple arms to close and remain in a closed condition when the mechanism is lifted by the load line, and means connecting the lifting section to the grapple to permit the grapple arms to open and remain in an open condition when the lifting and coupler sections are not interlocked when the mechanism is lifted by the load line. Description of the FIGS. l-7 Embodiment The lifting section of mechanism of the embodiment of FIGS. l-7 comprises a swivel cable rigging assembly 132 for attachment to a load line 122 that is axially rotatably journaled to the upper end of an axially moveable elongated rod 134. The lower end of rod 134 is rigidly attached to a transversely-extending, relatively narrow framework 138. A depending latch bar 140 is pivotally connected to the framework 138 axially below rod 134 by a pin 142 aligned perpendicular to the axis of rod 134 and to framework 138. A latch rod 141 extends transversely through the lower end oflatch bar 140 and protrudes from both sides thereof. A coil spring 144 is connected to the lower left side of latch bar 140 as viewed in FIG. 1 and extends upward around a pulley 146 mounted on framework 138 and over to a point of connection on the right handend of the framework as viewed in FIG. 1, thus to pivotally urge the latch bar upward to the left as viewed in FIG. 1. Two cable-supporting pins 148-150 are mounted on opposite ends of framework 138. Four upper

annular spring connectors

151, 152, 153 and 154 are mounted from the sides of the framework 138 in outrigger fashion inbounds of the pins 148-150 as viewed in FIGS. 1 and 6.

The coupler section of mechanism 120 of the embodiment of FIGS. 1-7 comprises a housing formed of two spaced apart, inwardly directed elongated channel members 160-162 interconnected across the top by a cross bar 164, which includes a guide sleeve 165 that axially encloses and guides rod 134, and across the bottom by plates 166-167. By reason of the channel members being spaced apart, elongated longitudinal guide slots 168-169 are provided in the housing through which the outer end sections of the framework 138 that contain pins 148-150 protrude for guidance when the framework 138 travels downwardly and upwardly in the housing. The lower ends of the channel members are connected to the links 106-108 by means of cross pin 139 extending therebetween. Cross pin 139 constitutes the aforementioned link pivot in this embodiment. Four lower

annular spring connectors

155, 157, 159 and 161 are mounted on and inwardly of the channel members, vertically below the respective upper spring connectors as shown in FIG. 7. Four coil springs 163 are connected to the respective vertically aligned upper and lower spring connectors.

A guide bar 170 is attached to the inner face of channel member 160 and extends inwardly toward the other channel member 162 a sufficient distance to be contacted by the adjacent end of the latch rod 141 of latch bar 140. The guide bar 170 maintains the latch bar 140 substantially vertical against the action of spring 144 when the framework 138 is in its uppermost position as shown in FIG. 1. At about the midpoint of the housing, the course of the guide bar 170 turns from the vertical and angles downwardly to the left as viewed in FIG. 1 then turns vertically downward again. A trap door latch 172, of sufficient thickness to be contacted by the aforesaid adjacent end of latch pin 141 of latch bar 140, is pivotally connected to the inner face of the channel member 160 and has a right hand edge 172a extending upwardly and to the left as viewed in FIG. 1. The latch 172 normally bears against the guide bar 170 at the break point from the latters vertical course to its angled course as shown in FIG. 1. A pair of substantially identical catch members l74174, of sufficient thickness to be contacted by the ends of the latch pin 141 of latch bar 140, are each connected at opposite points of the inner faces of one of the channel members 160-162, respectively, just below the trap door latch 172. The right hand edges 174a of the catch members as viewed in FIG. 1 are aligned with the right hand edge 172a of the trap door latch 172 and together with the edge 172a of latch 172 constitute a guideway for the latch pin 141 of latch bar 140. The bottom edges 174!) of the catch members are formed to provide the general outline of an inverted V that has a slight tilt to the left with the apex being in axial alignment with rod 134 as shown in FIG. 1. The left hand edge 174c of the catch member parallels the lower vertical course of the guide bar 170 as shown in FIG. 1. An inverted V shaped guide 176 of sufficient thickness to be contacted by the aforesaid adjacent end of latch pin 141 of latch bar is connected to the inner face of channel member below the adjacent catch member 174 with its apex slightly to the right of the axis of rod 134 as shown in FIG. 1. The trap door latch 172 is releasably urged against the guide bar by a coil spring 173 connected to the latch 172 to the left of its pivot point and connected to the adjacent catch member 174.

The mechanism 120 of the embodiment of FIGS. 1-7 also comprises a pair of cable guide assemblies 180-180 connected to opposite edges of the lower end of the housing and extending thereinto through the guide slots 168-169, respectively. These cable guide assemblies each constitute a sheave frame 181 which contains cable sheaves 182-183 adapted to direct a cable from the housing exterior to the housing interior, and a cable 184 connected to one of the cable supporting pins 148-150 of framework 138 and extending downward through one of the guide assemblies 180180 around the respective sheaves 182-183 and around the arm pivot and upward through the other guide assembly around the respective sheaves and connected to the other cable supporting pin as shown in FIG. 1. A sheave 186 may enclose the arm pivot to carry the cable 184 as shown in FIG. 1. The cable 184 is sufficiently long to permit the framework 138 to reach the position shown in FIG. 1 without binding the mechanism 120.

Operation of the FIGS. 1-7 Embodiment This embodiment is shown in FIGS. 1 and 3 in the position that would be assumed when the grapple arms are carried in a jaw open condition. The framework 138 is shown raised within the channel members 160-162 as high as permitted by the length of cable 184 as would occur by tightening and lifting on the load line 122. The grapple arms 100-100 are shown carried, or suspended, by cable 184 from the sheave 186. Because the housing defined by the channel members 160-162 is free to slide relative to the framework 138, the housing bears against the links 106-108 thereby forcing the link pivot 104 downward toward the arm pivot 110 as the rising framework 138 lifts the arm pivot 110 toward the link pivot 104. Thus, as stated above, FIG. 1 depicts the embodiment as it would appear when lifted by, or suspended from, load line 122 in a jaw open condition.

When the load line 122 is slacked off so as to relieve the lifting force on the cable rigging assembly 132, for example as would be the case when the grapple arms are lowered onto a log, the framework 138 will slide downwardly between the channel members 160-162. As the framework 138 slides downwardly, the latch pin 141 of the latch bar 140 will contact the edge 172a and trap door latch 172 and be deflected thereby to the right and onto the edges 174a of the catch members 174 as the framework continues to drop as depicted in dotted lines in FIG. 1. As the framework drops to its bottommost position, the latch pin 141 will clear the lower edges of the catch members 174 and swing leftward against the guide 176.

At this point, the load line 122 would be tightened and the framework 138 raised such that the latch pin 141 would be raised into an engaging position with the apexes of the bottom edges l74b of catch members 174 as shown in FIG. 2 and also shown in dotted lines in FIG. 1. As the framework 138 is further lifted by the load line 122, the channel members 160-162 will also be raised inasmuch as the channel members 160-162 are interlocked with the framework 138 through catch members 174 and latch bar 140. Because the link pivot 104 (pin 139) is connected to the channel members 160-162, lifting of these channel members will raise link pivot 104 relative to arm pivot 110 and effect the closing of the arms 100- 100 about the log. This position of the embodiment is shown in FIGS. 2 and 4. It will be noted that the cable 184 is sla c k when the framework 138 is in the FIG. 2 position thereby enabling the elevation of the arm pivot 110 to remain stationary as the link pivot 104 is raised to close the arms 100-100 about the log.

When the load line 122 is again slacked off so as to relieve the lifting force on the cable rigging assembly 132, for example as would be the case when the log gripped-by the grapple arm is lowered to the ground, the framework will slide downwardly a short distance to clear the latch pin 141 from the catch members 174, the spring 144 pulling the latch pin leftward against guide bar 170 as it clears the catch members as shown in dotted lines in FIG. 1. The load line 122 is then tightened to lift the framework 138 upward. The latch pin 141 upwardly traverses the course defined by the guide bar 170 past the trap door latch 172, swinging latch 172 out of the way as shown in dotted lines in FIG. 1. When the framework 138 reaches the position shown in FIG. 1, the cable 184 will become taut and the grapple arms 100-100 will once again be carried by cable 184 through the sheave 186. v

The coil springs 163 facilitate the above described telescoping interlocking action should an open grapple be dropped onto a log in a non-vertical manner.

It is to be noted from the foregoing description of operation of the FIGS. 1-7 embodiment that the interlocking and disengaging of the lifting and coupler sections of mechanism 120 does not in and of itself effect the opening or closing of the grapple arms 100-100. Rather, such interlocking and disengaging transfers the effect of lifting the mechanism 120 from either the link pivot 104 or the arm pivot 110 to the other. Thus, when the mechanism 120 is raised, the grapple arms will open or close depending on whether the mechanism 120 is interlocked or disengaged.

Description of the FIGS. 8-13 Embodiment The lifting section of mechanism 220 of this embodiment comprises a swivel cable rigging assembly 232 for attachment to a load line 222 that is axially rotatably journaled to the upper end of an axially movable elongated cylinder 234. A mounting plate 236 is connected to the interior surface of the upper end of wall 234a of the cylinder 234 and depends into the cylinder interior. A vertically depending latch finger 240 is pivotally connected to the lower end of plate 236 by pin 242. Latch finger 240 comprises a catch section 240a that depends downwardly from the connection with pin 242 and has 6 a slightly upwardly-inclined latch edge 241 that juts out to the right as shown in FIG. 8 and that is provided with an upper latch surface 241a and a lower cam surface 241b, both surfaces sloping upward to the right as viewed in FIG. 8. Latch finger 240 also comprises a section 240!) that extends outward to the right as viewed in FIG. 6 through an opening 2340 in the side wall of cylinder 234. A'coil spring 244 is connected to the plate 236 above and to the right of the axis of pin 242'and to an intermediate portion of the latch finger catch section below and to the left of the axis of pin 242. Thus, the spring will tend to pivot the latch finger counterclockwise when its center line extends to the right of the axis of pin 242 (as shown in FIG. 8) and will tend to pivot the latch finger clockwise when its centerline extends to the left of the axis of pin 242.

The lower section of cylinder 234 is cut away on diametrically opposite points to provide slots 246-246. The lower end of cylinder 234, between the slots 246-246, is provided with an outwardly extending seating rim 248. Two vertical inwardly opening guide channel members 250-252 are attached to the outer surface of cylinder 234 between the slots 246-246 as shown in FIG. 8 and extend substantially the full length of cylinder 234.

The coupler section of mechanism 220 comprises an inner sleeve 260 that is axially aligned and contained within the cylinder 234 and that is axially slidable therein. Sleeve 260 comprises an integral catch member 262 centrally positioned therein with a notch 263 having an upper surface 263a adapted to interlock with the latch edge 241a of latch finger 240 and having a bottom cam surface 263b that slopes downward to the left as viewed in FIG. 8 adapted to deflect the latch finger 240 clockwise as shown in dotted line in FIG. 9. The sleeve 260 is slotted at 265 to permit the latch finger 240, when deflected outward by contact with cam surface 263b, to contact the inner surface of cylinder 234 as shown in FIG. 12. The lower end of catch member 262 carries a pin 266 that pivotally interconnects the links 206-208 at the link pivot 204 as shown in FIG. 8.

The mechanism 220 also comprises an outer sleeve 280 that concentrically encloses the cylinder 234 and its vertical guide channel member 250-252. The outer sleeve 280 is adapted to slide upward on cylinder 234 until contact with the underside of the outwardly extending section 240b of latch finger 240 prevents further upward movement, and is adapted to slide downward on cylinder 234 until contact with the seating rim 248 on the lower end of cylinder 234 prevents further downward movement. A pair of grapple arm support legs 282-284 are pivotally connected to the side wall of sleeve 280 at pivot points 286-288 and are pivotally connected to the lower sections of grapple arms 200a-200a at pivot points 290-292. These legs 282-284 extend beyond pivot points 290-292 and inwardly toward one another as teethed log-engaging sections 282a-284a as shown in FIG. 8.

Operation of the FIGS. 8-13 Embodiment FIG. 8 depicts this embodiment as resting on a log with the grapple arms in a jaw open position preparatory to lifting the log, the load line 222 being in slack. The log-engaging sections 282a-284a of legs 282-284 bear against the log to hold the grapple arms off the log and, through the pivot connections at 290-292, hold them in the jaw open position. This grapple arm position as fixed by legs 282-284 determines the position 262 which are pivotally interconnected.

With the load line 222 slack, the cylinder 234 moves uwpardly a short distance until the surface 241a of latch finger 240 contacts the notch surface 263a of catch member 262 thereby interlocking the two elements. Further upward movement of cylinder 234 thus will effect a raising of link pivot 266 relative to arm pivot 210 to close the grapple arms about a log as shown in FIG. 9. With the closing of the grapple arms, the outer sleeve 280 will move downward on cylinder 234, as shown in FIGS. 9 and 11, away from contact with the section 240b of latch finger 240.

When the load line 222 is slacked off so as to relieve the lifting force on the cable rigging assembly 232, for exampleas would be the case when the log gripped by the grapple arms is lowered to the ground, the cylinder 234 and latch finger 240 pivotally connected thereto will move downward a slight distance whereupon the cam surface 24lb of latch finger 240 will contact cam surface 263b of catch member 262 and latch finger 240 will be pivoted clockwise to the position shown in dotted line in FIG. 9. The spring 244 will now be to the left of the axis of pin 242 as viewed in FIG. 9 and thus will hold the latch finger 240 in contact with the inner surface of cylinder 234. When the load line 222 is now tightened to lift the mechanism 222, cylinder 234 will move upward, latch finger 240 clearing catch member 262, until the rim 248 on the lower end of cylinder 234 contacts the outer sleeve 280. Further upwardmovement of cylinder 234 will lift the support legs 282-284 and open the grapple arms 200200, as shown in FIGS. 12 and 13.

When the load line is again slacked off as to relieve the lifting force on the cable rigging assembly 232, for example as would be the case when the grapple arms are lowered onto a log, the cylinder 234 will slide downward until the outer sleeve 280 contacts the section 240b of the latch finger 240 and pivots it counterclockwise to insert the latch edge 241 into the notch 263 to catch member 260 as shown in FIG. 8.

As in the FIGS. 1-7 embodiment, the interlocking and disengaging of the mechanism 220 of the FIGS. 8-13 embodiment transfers the effect of lifting the mechanism 220 from either the link pivot 204 or the arm pivot 210 to the other. Thus, when the mechanism 220 is raised, the grapple arms will open or close depending on whether the mechanism is interlocked or disengaged.

Description of the FIGS. 14-17 Embodiment The lifting section of mechanism 320 of the embodiment of FIGS. 14-17 comprises a swivel cable rigging assembly 332 for attachment to a load line 322 that is axially rotatably journalled to the upper end wall 334a of an axially movable elongated cylinder 334. The interior side of end wall 334a is provided with a downwardly depending cylindrical housing 335 that contains a thrust bearing assembly 336. The assembly 336 journal mounts a stub shaft 337 axially of the cylinder 334. An annular cam 338 is attached to the lower end of stub shaft 337 and contains a plurality of verticallydepending cam teeth 338a bevelled upward in a clockwise direction as viewed in FIG. 14 (eight being provided in the embodiment shown). A rotation restraining tab 338!) is attached to the cam 338 to prevent cam 338 from rotating in a counterclockwise direction. A

plurality of equi-spaced members 340 (four being depicted) are attached to the inner surface of the side wall of cylinder 334 and extend from above the mid point of the side wall to the lower end thereof as shown in FIG. 14. The inward faces of these members 340 are arcuate segments of a circle and the sides thereof are directed radially inward so as to provide an equal plurality of equi-spaced radially-oriented slots 342 (four being depicted). The upper ends of the members 340 are sealed to provide seating ledges 340a as shown in FIG. 14.

The coupler section mechanism 320 comprises an annular cam 360 containing a pluality of vertically upward-extending cam teeth 360a beveled downward in a counterclockwise direction as viewed in FIGS. 14 and 15 (eight being shown) and designed to rotatably interfit with the depending cam teeth 338a of cam 338. Cam 360 also contains a plurlaity of radial outwardextending lugs 362 (four being depicted) designed to slidably interfit the slots 342 as shown in dotted line in FIG. 15. Cam 360 is axially mounted on a stub shaft 364 that depends therefrom axially of cylinder 334 and is journal mounted by a thrust bearing assembly 366 within an inner cylindrical sleeve 368. Cam 360 is oriented with respect to cam 338 such that the edges of the respective cam teeth barely overlap when the lugs 362 are positioned on the seating ledges 340a. Sleeve 368 is guidably contained within the members 340 and has an elongated shaft 370 attached to the bottom wall thereof and depending therefrom through the cylinder 334 as shown in FIG. 14. The lower end of shaft 370 is pivotally connected to the grapple links 306-308 at the link pivot 304 by means of a connector 372. A pair of coil springs 374-376 may be connected to the interior. of cylinder 334 and to a cross bar 378 attached to the shaft 370 above the connector 372 as shown in FIG. 14.

The mechanism 320 also comprises a pair of cables 380-380 attached to exterior surface of the side wall of cylinder 334 and to the grapple jaw sections 300a300a as shown in FIGS. 16 and 17.

Operation of the FIGS. 14-17 Embodiment This embodiment is shown in FIG. 14 with the two sections of the mechanism 320 interlocked by reason of the lugs 362 being seated on the seating ledges 340a. Thus, the lifting section of the mechanism is interconnected to the link pivot 304 and lifting of the mechanism will close the grapple about a log and maintain the grip of the grapple thereon.

When the load line 322 is slacked off so as to relieve the lifting force on the cable rigging assembly 332, for example as would be the case when the log gripped between the grapple arms is lowered to the ground, the cylinder will move downward a short distance, contacting the out-of-registry cam teeth of cam 338 with the cam teeth of cam 360 whereby cam 360 will be forced to rotate in a clockwise direction to mesh the respective cam teeth. Because there are eight cam teeth on each cam, the cam 360 will rotate 45.and the lugs 362 will slide from the seating ledges 340a into the slots 342, thereby disengaging the two sections of the mechanism.

When the load line 322 is now tightened to lift the mechanism 320, cam 338, being free to rotate clockwise, will rotate slightly in a clockwise direction to release the respective cam teeth and the cylinder 334 will move upward relative to the link pivot 304 until the cables 380380 become taut. Further lifting will open the grapple arms and maintain the grapple arms in an open condition as shown in FIG. 16.

When the load line 322 is again slacked off to relieve the lifting force on the cable rigging assembly 332, for example as would be the case when the grapple arms are lowered onto a log, the cylinder 334 will move downward to contact the respective cam teeth of the cams 338-360 whereupon the lugs 362 of cam 360 will have cleared the slots 342. Contact between the respective cam teeth will force cam 360 to rotate in a clockwise direction 45 whereby lugs 362 will be centered above the seating ledges 340a. When the load line 322 is now tightened to lift the mechanism 320, the cylinder will be lifted, the legs 362 will contact seating ledges 340a, and the link pivot 304 will be raised to close the grapple arms about a log.

The coil springs 374-376 facilitate the above described telescoping interlocking action should an open grapple be lowered onto a log in a non-vertical manner.

As in the FIGS. 1-7 and the FIGS. 8-13 embodiment, the interlocking and disengaging of the mechanism 320 of the FIGS. 14-17 embodiment transfers the effect of lifting the mechanism 320 from either the link pivot 304 or the arm pivot 310 to the other. Thus, when the mechanism 320 is raised, the grapple arms will open or close depending on whether the mechanism isinterlocked or disengaged.

It is believed that the invention will have been clearly understood from the foregoing detailed description of my now-preferred illustrated embodiment. Changes in the details of construction may be resorted to without departing from the spirit of the invention and it is accordingly my intention that no limitations be implied and that the hereto annexed claims be given the broadest interpretation to which the employed language fairly admits.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

l. A single line grapple which comprises a pair of load lifting arms pivotally interconnected intermediate the ends thereof so as to provide lower jaw sections and upper actuating sections; a lift mechanism connectable to a load line for suspending said load lifting arms comprising (a) a coupler section interconnected with the upper sections of said load lifting arms, (b) a lifting section adapted for attachment to the load line for suspending said load lifting arms and adapted to move longitudinally relative to said coupler section in telescoping fashion to interlock with said coupler section to permit said load lifting arms to close and remain closed when said mechanism is lifted by the load line, and means interconnecting said lifting section and said load lifting arms to permit said load lifting arms to open and remain open when said mechanism is lifted by the load line with said lifting and coupler sections uncoupled, said coupler section and said lifting section each including means adapted to engage one another from a previously disengaged condition as the load line is slacked off and said lifting section telescopically moves downwardly to the maximum extent permitted by said coupler section such that when said mechanism is raised by the load line said coupler section and said lifting section will be interlocked.

2. A grapple according to claim 1 wherein said coupler section of said mechanism comprises catch means pivotally connected to the upper sections of said load lifting arms at a link pivot; and wherein said coupler section comprises pivotable latch means, said latch means being adapted to move longitudinally toward said catch means and pivot into load lifting engagement with said catch means such that lifting saidmechanism will raise said link pivot.

3. A grapple according to claim 1 wherein said coupler section of said mechanism comprises a housing pivotally interconnected with the upper sections of said load lifting arms, and catch means rigidly mounted in said housing; wherein said lifting section of said mechanism comprises a rod slidable within said housing and latch means pivotally interconnected to said rod and adapted to pivot into load lifting engagement with said catch means when said rod slides into said housing.

4. A grapple according to claim 1 wherein said coupler section of said mechanism comprises an inner sleeve pivotally interconnected with the upper sections of said load lifting arms, and catch means rigidly mounted in said inner sleeve; wherein said lifting section of said mechanism comprises a cylinder enclosing said inner sleeve and latch means pivotally interconnected to said cylinder and adapted to fit into said inner sleeve and to pivot into load lifting engagement with said catch means when said cylinder slides downward around said inner sleeve.

5. A grapple according to claim 1 wherein said coupler section comprises a rod pivotally interconnected with the upper sections of said load lifting arms, and indexable and rotatable catch means journal mounted to the upper end of said rod with lugs extending outwardly therefrom; wherein said lifting section comprises a cylinder enclosing said rod and catch means and provided with spaced seating ledges on the interior thereof and an indexing assembly adapted to rotate said catch means to align said lugs with said seating ledges when said cylinder slides downward around said rod and catch means.

6. A single line grapple which comprises a pair of load lifting arms pivotally interconnected intermediate the ends thereof so as to provide lower jaw sections and upper actuating sections; a coupler section comprising a housing pivotally interconnected to the upper sections of said load lifting arms, catch means rigidly mounted in and to said housing, and guide means mounted in said housing above said catch means; a lifting section comprising a cable rigging assembly, a pivotable latch bar slidably contained in said housing and interconnected to said rigging assembly in a load lifting connection and adapted alternately (a) to be guided downward from an uncoupled condition along one course by said guide means and thence pivot into load lifting engagement with said catch means and (b) to pivot out of load lifting engagement with said catch means and thence to be guided upward along another course by said guide means to return to said uncoupled condition when the load line is slacked off and then tightened; said coupler section and said lifting section being so constructed that said latch bar and said catch means are adapted to engage one another from a previously disengaged condition as the load line is slacked off and said lifting section telescopically moves downwardly to the maximum extent pennitted by said coupler section such that when said mechanism is raised by the load line said coupler section and said lifting section will be interlocked; and means interconnecting said lifting section and said load lifting arms to permit said load lifting arms to open and remain open when said lifting section is raised in said uncoupled condition.

7. A grapple according to claim 6 wherein said coupler section guide means comprises a guide bar mounted in said housing, a trap door latch releasably urged against said guide bar and pivotally mounted in said housing between an upper section of said guide bar and said catch means; and wherein said latch bar is adapted to bear against said guide bar and trap door latch when downwardly traversing said one course and adapted to bear against said guide bar and to pivot said trap door latch away from said guide bar when upwardly traversing said other course.

8. A grapple according to claim 6 wherein said coupler section housing has parallel side walls and an elongated slot in two opposing side walls; wherein said catch means comprises two catch members attached to opposite inner faces of the non-slotted side walls, each having a side guide edge aligned one with the other and a notched load-supporting underedge; and wherein said guide means comprises a guide bar mounted on an interior face of one non-slotted side wall and extending vertically downward from the upper section of said housing toward said catch members and, thence nonvertically downward away from said catch members and thence vertically downward alongside said catch members, and a trap door latch pivotally mounted on the interior face of said one non-slotted wall between the catch member mounted on such wall and said guide bar and extending substantially therebetween and releasably urged against said guide bar to divert said latch box away from said guide bar when said latch bar'traverses its downward course, said trap door latch having a side guide edge; and wherein said latch bar is releasably urged against said guide and includes a latch pin extending therefrom sufficiently to contact said guide bar, said trap door latch and said catch members; and wherein said lifting section includes a frame contained within said housing with outer ends protruding through the opposing slots in said housing.

9. A grapple according to claim 6 wherein said means interconnecting said lifting section and said load lifting arms comprises a pair of cable guide assemblies mounted on opposite sides of said coupler section housing for guide cable into said housing, and a cable connected to one side of said lifting section and extending downward through one of said cable guide assemblies into said housing and around the pivotal connection between said load lifting arms and upward into said housing and through the other of said cable guide assemblies and connected to the opposite side of said lifting section.

10. A single line grapple which comprises a pair of load lifting arms pivotally interconnected intermediate the ends thereof so as to provide lower jaw sections and upper actuating sections; a coupler section comprising an inner sleeve pivotally interconnected to the upper sections of said load lifting arms, catch means rigidly mounted in and to said inner sleeve; a lifting section comprising a cable rigging assembly, a cylinder journaled to said rigging assembly and slidably enclosing said inner sleeve, a latch finger pivotally connected to said cylinder and depending into said cylinder and adapted alternately (a) to interlock with said catch means in a load lifting connection and (b) to pivot out of load lifting connection with said catch means when the load line is slacked off and then tightened; said coupler section and said lifting section being so constructed that said latch finger and said catch means are adapted to engage one another from a previously disengaged condition as the load line is slacked off and said lifting section telescopically moves downwardly to the maximum extent permitted by said coupler section such that when said mechanism is raised by the load line said coupler section and said lifting section will be interlockd; and means interconnecting said lifting section and said load lifting arms to permit said load lifting arms to open and remain open when said lifting section is raised in an uncoupled condition.

11. A grapple according to claim 10 wherein said latch finger comprises a catch section extending downwardly from its pivotal connection and an actuating section extending outwardly from its pivotal connection through a slot in said cylinder, said catch section being provided with laterally extending upwardly faced latch edge and a downwardly faced bottom cam edge; and wherein said coupler section catch means comprises a catch member provided with a notch having a downwardly faced upper latch edge and an upwardly faced lower cam edge; and including spring means connected to the latch finger catch section and to said load lifting section above the pivotal connection with said latch finger at a point where the axis of said spring means passes to one side or the other of the pivotal axis of said latch finger depending on whether said latch finger is coupled or uncoupled.

12. A grapple according to claim 10 wherein said means interconnecting said lifting section and said load lifting arms comprises an outer sleeve slidably encircling said cylinder,and a pair of grapple arm support legs pivotally connected to the side wall of said outer sleeve and to the lower sections of said load lifting arms, said support legs extending inwardly toward one another from their respective pivotal connection with the lower sections of said load lifting arms.

13. A single line grapple which comprises a pair of load lifting arms pivotally interconnected intermediate the ends thereof so as to provide lower jaw sections and upper actuating sections; a coupler section comprising a rod pivotally interconnected to the upper sections of said load lifting arms, an annular indexable cam journal mounted to said rod and provided with upwardly extending cam teeth and outwardly extending load supporting lugs; a lifting section comprising a cable rigging assembly, a cylinder journal mounted to said rigging assembly, an annular indexing cam journal mounted to said cylinder and provided with downwardly extending cam teeth adapted to contact and mesh with the cam teeth of said coupler section cam, and means providing alternating load supporting seating ledges and guide slots for the lugs of said coupler section cam and being located such that said lugs are raised above said seating ledges when the coupler section and lifting section cams contact, the respective cam teeth being designed to effect rotation of said coupler section cam to alternately index said lugs over said seating ledges and over said slots; said coupler section and said lifting section being so constructed that said lugs and said ledges are adapted to engage one another from a previously disengaged condition as the load line is slacked off and said load lifting section telescopically moves downwardly to the maximum extent permitted by said coupler section such that when said mechanism is raised by the load line said coupler section and said lifting section will be interlocked; and means interconnecting said lifting section and said load lifting arms to permit said load lifting arms to open and remain open when said lifting section is raised with said lugs in said guide slots.

14. A single line grapple which comprises a pair of load lifting arms pivotally interconnected intermediate the ends thereof so as to provide lower jaw sections and upper actuating sections; amechanism connectable to a load line for suspending said load lifting arms comprising (a) a coupler section interconnected with the upper sections of said load lifting arms by means providing a rigid connection between said load lifting arms and said coupler section in the plane defined by said load lifting arms and providing a flexible connection between said load lifting arms and said coupler section in a plane perpendicular to the plane defined by said load lifting arms, (b) a lifting section adapted to move longitudinally relative to said coupler section in telescoping fashion to interlock with said coupler section to permit said load lifting arms to close and remain closed when said mechanism is lifted by the load line, said coupler section and said lifting section each including means adapted to engage one another from a previously disengaged condition as the 'load line is slacked off and said lifting section telescopically moves downwardly to the maximum extent permitted by said coupler section such that when said mechanism is raised by the load line said coupler section and said lifting section will be interlocked, (c) means interconnecting said lifting section and said load lifting arms to permit said load lifting arms to open and remain open when said mechanism is lifted by the load line with said lifting and coupler sections uncoupled, and (d) a swivel load line rigging assembly axially rotatably journalled to said lifting section for attachment to the load line for suspending said load lifting arms such that said load lifting arms may swivel into transverse engagement with their log upon being dropped thereof.

15. The single line grapple of claim 14 including links pivotally connected to the outer ends of said upper actuating jaw sections and pivotally connected together at a link pivot point; and wherein said coupler section includes a cross-pin extending perpendicular to the plane defined by said load lifting arm and interconnecting said link at said link pivot point.

16. An automatic one line grapple for logging or the like comprising a vertically disposed shaft having means thereon for connection with a support, a frame moveably supported from the shaft for relative vertical movement in relation thereto, a tong assembly attached to and depending from the frame for opening and closing in response to said relative vertical movement, and means interconnecting the shaft and frame for sequentially locking the frame to preclude said relative vertical movement and releasing the shaft from the frame to permit said relative vertical movement, said tong assembly including a pair of crossed tong members pivotally interconnected by a center pivot at a point of crossing thereof, a pair of links attached to the end of the tong members disposed above the center pivot, a pivot pin connecting the upper ends of the links to the frame for support of the tong assembly to cause the tong members to pivot towards each other about the center pivot and close, tension means having a portion thereof engageable with the tong assembly, and means connected to another portion of the tension means for selectively transferring the load of the tong assembly to the center pivot to open the tong members.

17. The grapple as defined in claim 16 wherein said center pivot between the crossed tong members includes a sleeve thereon, said tension member being in the form of a cable entrained over said sleeve, said sleeve being smooth thereby eliminating chaffing and jamming of the cable during pivotal movement of the tong members.

18. The grapple as defined in claim 16 wherein said shaft includes shiftable means on the lower end thereof in engagement with said frame, and means on the frame for engaging the shiftable means to position the shiftable means in position for selective lifting engagement with the frame at a position below the point of engagement between the shaft and tension member whereby the tension member will not support the center pivot of the tong members even when fully closed, the other position of the shiftable means permitting the shaft to move upwardly to engage and to operatively exert tension force on the tension member to support the tong members from the center pivot to open the same.

Claims

1. A single line grapple which comprises a pair of load lifting arms pivotally interconnected intermediate the ends thereof so as to provide lower jaw sections and upper actuating sections; a lift mechanism connectable to a load line for suspending said load lifting arms comprising (a) a coupler section interconnected with the upper sections of said load lifting arms, (b) a lifting section adapted for attachment to the load line for suspending said load lifting arms and adapted to move longitudinally relative to said coupler section in telescoping fashion to interlock with said coupler section to permit said load Lifting arms to close and remain closed when said mechanism is lifted by the load line, and (c) means interconnecting said lifting section and said load lifting arms to permit said load lifting arms to open and remain open when said mechanism is lifted by the load line with said lifting and coupler sections uncoupled, said coupler section and said lifting section each including means adapted to engage one another from a previously disengaged condition as the load line is slacked off and said lifting section telescopically moves downwardly to the maximum extent permitted by said coupler section such that when said mechanism is raised by the load line said coupler section and said lifting section will be interlocked.

2. A grapple according to claim 1 wherein said coupler section of said mechanism comprises catch means pivotally connected to the upper sections of said load lifting arms at a link pivot; and wherein said coupler section comprises pivotable latch means, said latch means being adapted to move longitudinally toward said catch means and pivot into load lifting engagement with said catch means such that lifting said mechanism will raise said link pivot.

6. A single line grapple which comprises a pair of load lifting arms pivotally interconnected intermediate the ends thereof so as to provide lower jaw sections and upper actuating sections; a coupler section comprising a housing pivotally interconnected to the upper sections of said load lifting arms, catch means rigidly mounted in and to said housing, and guide means mounted in said housing above said catch means; a lifting section comprising a cable rigging assembly, a pivotable latch bar slidably contained in said housing and interconnected to said rigging assembly in a load lifting connection and adapted alternately (a) to be guided downward from an uncoupled condition along one course by said guide means and thence pivot into load lifting engagement with said catch means and (b) to pivot out of load lifting engagement with said catch means and thence to be guided upward along another course by said guide means to return to said uncoupled condition when the load line is slacked off and then tightened; said coupler section and said lifting section being so constructed that said latch bar and said catch means are adapted to engage one another from a previously disengaged condition as the load line is slacked off and said lifting section telescopically moves downwardly to the maximum extent permitted by said coupler section such that when said mechanism is raised by the load line said coupler section and said lifting section will be interlocked; and means interconnecting said lifting section and said load lifting arms to permit said load lifting arms to open and remain open when said lifting section is raised in said uncoupled condition.

8. A grapple according to claim 6 wherein said coupler section housing has parallel side walls and an elongated slot in two opposing side walls; wherein said catch means comprises two catch members attached to opposite inner faces of the non-slotted side walls, each having a side guide edge aligned one with the other and a notched load-supporting underedge; and wherein said guide means comprises a guide bar mounted on an interior face of one non-slotted side wall and extending vertically downward from the upper section of said housing toward said catch members and thence non-vertically downward away from said catch members and thence vertically downward alongside said catch members, and a trap door latch pivotally mounted on the interior face of said one non-slotted wall between the catch member mounted on such wall and said guide bar and extending substantially therebetween and releasably urged against said guide bar to divert said latch box away from said guide bar when said latch bar traverses its downward course, said trap door latch having a side guide edge; and wherein said latch bar is releasably urged against said guide and includes a latch pin extending therefrom sufficiently to contact said guide bar, said trap door latch and said catch members; and wherein said lifting section includes a frame contained within said housing with outer ends protruding through the opposing slots in said housing.

10. A single line grapple which comprises a pair of load lifting arms pivotally interconnected intermediate the ends thereof so as to provide lower jaw sections and upper actuating sections; a coupler section comprising an inner sleeve pivotally interconnected to the upper sections of said load lifting arms, catch means rigidly mounted in and to said inner sleeve; a lifting section comprising a cable rigging assembly, a cylinder journaled to said rigging assembly and slidably enclosing said inner sleeve, a latch finger pivotally connected to said cylinder and depending into said cylinder and adapted alternately (a) to interlock with said catch means in a load lifting connection and (b) to pivot out of load lifting connection with said catch means when the load line is slacked off and then tightened; said coupler section and said lifting section being so constructed that said latch finger and said catch means are adapted to engage one another from a previously diSengaged condition as the load line is slacked off and said lifting section telescopically moves downwardly to the maximum extent permitted by said coupler section such that when said mechanism is raised by the load line said coupler section and said lifting section will be interlocked; and means interconnecting said lifting section and said load lifting arms to permit said load lifting arms to open and remain open when said lifting section is raised in an uncoupled condition.

12. A grapple according to claim 10 wherein said means interconnecting said lifting section and said load lifting arms comprises an outer sleeve slidably encircling said cylinder, and a pair of grapple arm support legs pivotally connected to the side wall of said outer sleeve and to the lower sections of said load lifting arms, said support legs extending inwardly toward one another from their respective pivotal connection with the lower sections of said load lifting arms.

14. A single line grapple which comprises a pair of load lifting arms pivotally interconnected intermediate the ends thereof so as to provide lower jaw sections and upper actuating sections; a mechanism connectable to a load line for suspending said load lifting arms comprising (a) a coupler section interconnected with the upper sections of said load lifting arms by means providing a rIgid connection between said load lifting arms and said coupler section in the plane defined by said load lifting arms and providing a flexible connection between said load lifting arms and said coupler section in a plane perpendicular to the plane defined by said load lifting arms, (b) a lifting section adapted to move longitudinally relative to said coupler section in telescoping fashion to interlock with said coupler section to permit said load lifting arms to close and remain closed when said mechanism is lifted by the load line, said coupler section and said lifting section each including means adapted to engage one another from a previously disengaged condition as the load line is slacked off and said lifting section telescopically moves downwardly to the maximum extent permitted by said coupler section such that when said mechanism is raised by the load line said coupler section and said lifting section will be interlocked, (c) means interconnecting said lifting section and said load lifting arms to permit said load lifting arms to open and remain open when said mechanism is lifted by the load line with said lifting and coupler sections uncoupled, and (d) a swivel load line rigging assembly axially rotatably journalled to said lifting section for attachment to the load line for suspending said load lifting arms such that said load lifting arms may swivel into transverse engagement with their log upon being dropped thereof.