CA1040593A - Stop for crane boom - Google Patents
Stop for crane boomInfo
- Publication number
- CA1040593A CA1040593A CA262,218A CA262218A CA1040593A CA 1040593 A CA1040593 A CA 1040593A CA 262218 A CA262218 A CA 262218A CA 1040593 A CA1040593 A CA 1040593A
- Authority
- CA
- Canada
- Prior art keywords
- boom
- stop
- axis
- stop rod
- pivotally connected
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Landscapes
- Jib Cranes (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A crane has a rotatable body with a vertically pivotal boom connected thereto. An energy absorbing stop unit is mounted in a fixed position on the body, and a guide sleeve is pivotally mounted on the body adjacent the stop unit. A stop rod is pivotally connected to the boom at a point between the ends of the boom for vertical swinging movement, and the rod is maintained in the guide sleeve in every position of the boom. The guide sleeve is pivoted by the stop rod into alignment with the stop unit at the extreme upper position of the boom, and, at that position of the boom, the stop rod extends through the guide sleeve into engagement with the stop unit.
-1a-
A crane has a rotatable body with a vertically pivotal boom connected thereto. An energy absorbing stop unit is mounted in a fixed position on the body, and a guide sleeve is pivotally mounted on the body adjacent the stop unit. A stop rod is pivotally connected to the boom at a point between the ends of the boom for vertical swinging movement, and the rod is maintained in the guide sleeve in every position of the boom. The guide sleeve is pivoted by the stop rod into alignment with the stop unit at the extreme upper position of the boom, and, at that position of the boom, the stop rod extends through the guide sleeve into engagement with the stop unit.
-1a-
Description
: 1~4~593 BACKGROU~D OF THE INVEN'rION
Field of the Invention This in~ention relates to a hoom crane and, more particularly0 to a stop for the boom of such a crane to preven~ upward movement of the crane boom be~ond a pre- ~-determined extreme upper position.
- In boom cranes, the boom stxucture, which is usually pivotally mounted on the revolving superstructure of t~e machine for vertical swinging~ is normally sup- ~
por~ed by wire ropes extending from a winch on the super- -~tructure to the outer point of the boom, and the load is raised or lowered by a wire rope extending rom a winch on ~he re~olving s~perstructure over a sheave at the outer point of the boom. When such ~achine~ are in use, ~here is a danger that the ~oom will recoil, or swing upwa~dly past a vertical position and back over the frame, in the e~ent the load is suddenly released, such as by the breaking of a wire rope.
Crane boom stops normally limit boom rotation by providing a physical connection between the revolving super-structure and the base section of the boom to lLmit the boom angle (angle between the horizontal and the boom centerlinel to 90 or less.
Description of the Prior Art Of the devices presently used to limit boom rota-tion beyond a predetermined extreme upper position, the most basic is the "ixed" or "rigid" type boom stop. This usually consists of some structure mounted rigidly to either the boom or the revolving superstructure. The structure is contacted by the member (boom or superstruc-4~i93 ture) at the desired maximum boom angle.
Ano~her type of boom stop commonly used is one composed of two tubular,strutsO each pivotally connected to the superstructure. Two link-type members pivotally con-nect the boom lower section to the extending ends of the ,~ struts. These links, following the booms vertical ,~
rotation, guide the strut ends toward target pads on the boom. ~ similar operating boomstop device can be made ~ .:
, by mounting the tubular struts to the boom and the guiding links to the revolving s~perstructure. ~See United States patents 20999,601; 3,123,223; and 3,647,087 ~ he "rail" type boom stop is another device some-times used to limit boom elevation. Two tubular struts e~tend from the revolving superstructure toward the boom. ....... ..
; 15 These strut5 are not connected to the boom when the boom ,, is at low angles. ~s the boom is raised to a working angle~
rollers on the ends of the struts engage rails fastened to the boom. ~he rollers ride on the rails as the boom rises and guide the strut ends to targets on the boom when the boom attains a maximum angle. An example of the rail `S~ `
type stop for a boom is shown in United States patent `-3,092,261. ...
Still another, boom stop device utilizes wire rope ;~, to stop boom elevation. One or more wire ropes are - "
attached to the revolving superstructure and pass under the boom hinge to attach to the under side of the boom~ As ,, the boom reaches its highest angle, the wire ropes tighten -,~
and restrain the boom from further elevation~
Another type of boom stop consists of a pair of~ , telescopic, strut-like members, which are pivotally con- ,; ,,; , `':;,' '
Field of the Invention This in~ention relates to a hoom crane and, more particularly0 to a stop for the boom of such a crane to preven~ upward movement of the crane boom be~ond a pre- ~-determined extreme upper position.
- In boom cranes, the boom stxucture, which is usually pivotally mounted on the revolving superstructure of t~e machine for vertical swinging~ is normally sup- ~
por~ed by wire ropes extending from a winch on the super- -~tructure to the outer point of the boom, and the load is raised or lowered by a wire rope extending rom a winch on ~he re~olving s~perstructure over a sheave at the outer point of the boom. When such ~achine~ are in use, ~here is a danger that the ~oom will recoil, or swing upwa~dly past a vertical position and back over the frame, in the e~ent the load is suddenly released, such as by the breaking of a wire rope.
Crane boom stops normally limit boom rotation by providing a physical connection between the revolving super-structure and the base section of the boom to lLmit the boom angle (angle between the horizontal and the boom centerlinel to 90 or less.
Description of the Prior Art Of the devices presently used to limit boom rota-tion beyond a predetermined extreme upper position, the most basic is the "ixed" or "rigid" type boom stop. This usually consists of some structure mounted rigidly to either the boom or the revolving superstructure. The structure is contacted by the member (boom or superstruc-4~i93 ture) at the desired maximum boom angle.
Ano~her type of boom stop commonly used is one composed of two tubular,strutsO each pivotally connected to the superstructure. Two link-type members pivotally con-nect the boom lower section to the extending ends of the ,~ struts. These links, following the booms vertical ,~
rotation, guide the strut ends toward target pads on the boom. ~ similar operating boomstop device can be made ~ .:
, by mounting the tubular struts to the boom and the guiding links to the revolving s~perstructure. ~See United States patents 20999,601; 3,123,223; and 3,647,087 ~ he "rail" type boom stop is another device some-times used to limit boom elevation. Two tubular struts e~tend from the revolving superstructure toward the boom. ....... ..
; 15 These strut5 are not connected to the boom when the boom ,, is at low angles. ~s the boom is raised to a working angle~
rollers on the ends of the struts engage rails fastened to the boom. ~he rollers ride on the rails as the boom rises and guide the strut ends to targets on the boom when the boom attains a maximum angle. An example of the rail `S~ `
type stop for a boom is shown in United States patent `-3,092,261. ...
Still another, boom stop device utilizes wire rope ;~, to stop boom elevation. One or more wire ropes are - "
attached to the revolving superstructure and pass under the boom hinge to attach to the under side of the boom~ As ,, the boom reaches its highest angle, the wire ropes tighten -,~
and restrain the boom from further elevation~
Another type of boom stop consists of a pair of~ , telescopic, strut-like members, which are pivotally con- ,; ,,; , `':;,' '
-2-4~5~3 nected to the revolving superstructure and the boom lower section. The strut~like members pivot vertically and telescope to allo~ the boom freedom to rotate in a verti-cal plane in the working range~ The struts restrict the boom to some maximum angle by some means which stops the telescopic action at some preset maximum boom angle.
The mechanism w~ich incorporates the t~elescoping members ~ -- has these advantages over the previously mentioned stop devices. ~-~13 With the telescopic device, ~he stopping fo~ce can be applied at a higher point on the boom than the other stop devices becau~e o~ its telescopic ability to change length and ~ollow boom elevation. The application o~ the stopping force at a higher point on the boom reduces stresses in the boom and stops when boom restraint is re~uired.
(~) Telescopic devices do not have free ends which can oscillate while the mach~ne i5 working because they are pivotally connected to both the revolving superstructure and the boom at all times.
The mechanism w~ich incorporates the t~elescoping members ~ -- has these advantages over the previously mentioned stop devices. ~-~13 With the telescopic device, ~he stopping fo~ce can be applied at a higher point on the boom than the other stop devices becau~e o~ its telescopic ability to change length and ~ollow boom elevation. The application o~ the stopping force at a higher point on the boom reduces stresses in the boom and stops when boom restraint is re~uired.
(~) Telescopic devices do not have free ends which can oscillate while the mach~ne i5 working because they are pivotally connected to both the revolving superstructure and the boom at all times.
(3) Telescopic devices ut~lize columnar members to carry the stopping force of the boom so ~hat they may be sized to carry any load required. Wire ropes used in devices have a practical size limitation because they musk be reasonably flexibleO
Stop mechanism with telescopic members are shown in United States patents 2,479,838; 2,509,686; 2,627,985;
. . . . .
,~ .
~,, 55~3 2,840,244; and 3,097,749.
Another boom stop device of interest is the one shown in --United States patent 3,076,560. In this device two rods are pivotally connected to the boom. Each is received in a trunnion pivotally connected to the mast. A stop is fixed on the superstructure which is -,. :-.
engaged by the rod when the boom reaches its extreme upper position. ~
:~
Any or all of the previously mentioned stop devices may be equipped with some type of energy absorbing or energy dissipating `~' mechanisms. The purpose of ~hese mechanisms is to reduce the impact loadings encountered in stopping a recoiling boom. The energy absorbing ~`
devices commonly used include: springs, bumpers, and/or compressed air `
cushions.
SUMMARY 0~ T~IE INVENTION
According to the present invention, there is provided in a crane having a body and having a boom pivotally connected to the body, ; said crane having a stop rod pivotally connected to the boom and having a stop member mounted on the body, said crane having a guide sleeve, the improvement wherein said guide sleeve is pivotally mounted on the "`
body to receive the stop rod therein and is pivotal on the body by the ;
stop rod, said sleeve terminating near the stop member when the boom is in the extreme upper position to guide the outer end of the stop rod into engagement with the stop member.
In the preferred embodiment, the invention, a pair of stop rods are pivotally connected to the boom and a pair of stop units are , ~ , fixed to the body, or superstructure, of the crane, with an-elongated ;
sleeve is pivotally connected to the superstructure close to each fixed `
stop unit. As the boom reaches its extreme upper position, the stop '~
rods extend through the sleeves and into engagement with the fixed stop units. Since the sleeves are pivotally mounted on a fixed axis to the 3Q same body on which the stop units are secured, and since the sleeves ,..
~,, '.
:: :: `..
:~ :
~L04~593 :
,.:, , .:
`, extend into close proximity to the stop units, the stop rods are positively ; -guided, without risk of misalignment due to flexing of the crane membersJ
into engagement with the stop units. The stop rods act as columns in t compression when s~opping the upward movement of the boom, and the ~ sleeves prevent the columnar rods from buckling ~lder the load imposed ; by the boom. At the same time, the device of the present invention ~-' incorporates all the advantages of conventional telescopic boom stop devices.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings which illustrate an exemplary `
embodiment of the present invention:
Figure 1 is a side elevational view of a crane incor- r porating a boom stop.
Figure 2 is an enlarged view, taken as the view of Figure 1, of the stop mechanism. `
Figure 3 is a central section of the energy absorbing device utilized in the stop mechznis=, shown ~ust ' ::
''. ' . - 5 -` ~
~L04~S93 ~`
before impact o the stop rod as the boom approaches its -extreme upper position. -~
Figure 4 is a fragmentary plan view, taken on the - line 4-4 of ~igure 2, of the stop mechanism.
Figure 5 is a view in perspective of the guide sleeve mounting mechanism~
Figure 6 is a schematic perspective view o~ th~
stop mechanism.
DESCRIPTION OF THE PREFERRED EMlBODIMEl!~T "` .
. , .
There is shown in Figure 1 a crane 10 havin~ a superstructureO or bod~, 12 and a caxriert or chassis, ~4 The carrier 14 is shown with a frame 14a and an endless ~ ~ .
crawler track 14b mounted on sprockets 14c journaled in the ~rame, but it may, instead, comprise a ~rame with wheels.
; 15 The ~ody 12 ha~ a ~rame 12a for mounting much o~ the cran~
machiner~, a pedestal 12b on the frame or pivotally ....
mounting a boom 16, and a housing 12c secured to and enclosing ~he frame. The boom 16 is pivotally connected to the pedestal 12b on axis A for vertical swinging move- ;~
ment, and body 12 is pivotally mounted on the chassis 14 ,-for swinging movement about axis B. ;
A stop rod 18 is connected at one end to each ~;~
side of the boom 16 (at a poin~ C) for pivotal movement .: : .
with respect to the boom about horizontal axis Do It will be noted that each point C is spaced from the axis A
about which the boom swings on the body a distance R.
Thus, as the boom swings between a position on the ground .
~shown in dotted lines and indicated at 16') and a desired extreme upper position (shown in dotted lines and indi-cated at 16"), the point C follows a circular path P
, ' .' , .. . .
..
' ~04~93 : `
about axis A~ Consequently, the boom end o each stop rod 18 must move along the path P as the boom swings between the two eætreme positions 16' and 16".
A5 shown best in Figure 2, an elongated guide sleeve 20 for each stop rod 18 is mounted to the body, or superstructure, 12 for pivotal movement about a hoxizontal axis E which is spaced from the sleave and from the longi- ~:
tudinal axis F thereof~ Each sleeve receives ~he stop rod ~.-18 ~herein~ and the sleeves are long enough to support the ends of the rods opposite the boom ends in any position`
~o~ the boom between the two extreme positions 16' and 16".-A bracket 22 is wel~ed to the body rame 12a *or each sleeve 20, and a support brac~et 23 is secured to each bracket 22. Each suppork bracket has a pair o.~ upstanding 1~ ears 24. ~n ear 25 secured ~o the end of the guide sleeve 20 remote from the boom, is received between the ears 24 :and pivotally connected thereto by pin 26 which lies in the pivot axis E. Each stop rod 18 slides longitudinally in the sleeve 20 from an extended position in the sleeve when the boom is in the lower extreme position 16', to a telescopea position in the sleeve when ~he boom is in the upper extreme position 16". When the boom is in the latter position~ each stop rod and sleeve will lie in an axis G, and the distal, or free, end of the stop rod will extend from the end of the~sleeve ~which is open at both ends) remote from the boom.
A stop unit 28 is secured to the body, or .
superstructure 12a, on each axis G for engagement by the distal, or free end of each stop rod 18 when the boom i5 in the desired upper extreme position 16".
~41)593 ~ ::
As sho~n best in Figure 3, each stop unit has an outer casing 30 which is secured to the frame 12a of the body by a bracket 31. Each stop unit casing has a ring 32 secured in ~he lower, or remote, end thereof. A
shorter, smaller inner tube 34 has its lower, or remote, `; end secured inside the ring. The upper end of tube 34 is closed by plate 36 which has a central opening 38 ther~in.
An abutment plate 40~ having a dished forward face 42 to receive the rounded free end 44 of stop rod 18, is mounted on a disc 46 which is received in the open !'.
front end o casing 30~ A spring backing plate 48 is secured by spacer sleeve 50 to disc 46~ A small tube 52 ;~ extends through backing plate 48, disc 46, and abutment ; ~ `
plate 40 to terminate at its forward end in the center o~
the face 4~. Tube 52, which is secured to plate 40, disc 46 and plate 48, extends rearwardly through the opening 38 in plate 36, but is not secured to the plate 36. A washer 54, nut 56 and lock nut 58 are received on the tube in -~
sleeve 34, the washer in engagement with plate 36. The nuts, which are in threaded engagement with the tube, are drawn up again~t the washer to prevent forward movement of the tube 52 beyond the point whera disc ~6, which i9 secured to tube 52, is flush with the forwaxd end of casing 30.
A compression spring 60 is received in casin~ 30, over tube 34, and between rear ring 32 and spring backing plate 48. Thus, when the remote end 44 of stop rod 18 engages abubment plate 40 as the boom reaches its upper extreme position 16", the assembly of plate 40, disc 46, '''` ~.
--8-- ~ .
, ,,~
~4~S93 - spacer 50 and ~late 48 is forced into the casing 30, com- .. .
pressing spring 60 to absorb the impact of ~he elevating boom. After the spring is compressed to stop the boom, the stored energy of the sprin~ returns ~he head assembly (40, 46, 50 and 48) to the extended position with disc 46 flu.sh wi-th the end of casing 30O
.. ~
An artuator rod 62, having a head 640 is xe- ;
ceived in t~bé S2 of one of the stop units. A lever 66.is hel~ b~ bracket 68 and bolt 70, over ~he remote encl of casing 30 of that unit. Rod 62 extends thxough an opening in le~er 66 and is prevented from forward movement with respect t~exeto by washer 74, nut 76 and lock nut 7 spring 80, xeceived in an enlarged bore portion oE tubo 52 and engaged with head 64 of rod 62, urges rod 62 for-ward with hea~ ~4 protruding from face 42 of abutment plate 40. When -~he head 64 i5 engaged by stop rod 18, the '~
lever 66, which is biased away rom casing 30, is released. ~s the lever 66 moves away from casing 30, the spring biased switch 82, mounted on casing 30, is released to cut the power to the boom elevating mechanism~
In operation of the stop mechanism of the pre-sent invention, it should be noted that the stop rods 18 are maintained within the sleeves 20 in every position o~
; . the boom 16. As the boom is raised, the boom end of each stop rod 18 moves in the circular arc P by virtue of its pivotal connection to the boom. The stop rods 18 thus swing the sleev~s ~0 toward the axis G as the boom approaches its ex~reme UppeL position 16". As the distal end of the stop rods reach the abutment plates 40 of the stop units, the shock of the impact is absorbed by the _g_ , .,. . ,; . ~.
{)593 spring 60. At ~he same time, the rod 62 is actuatea to operate switch 82 and thereby shut off the boom elevating `~
machinery.
Thus it wil~ be seen that a simple, effective telescopic boom stop mechanism is provided in which stop rods act as column in compression as they tran~er the impact of the elevating boom to shock absorbing stop units. `~
The columns defined by the stop rods are guided in~o pro per contact with the units by the sleeves by virtue of t~eix offset pivot axis. At the same time, the guide sleeves, which themselves do not take any of the load of the elevating boom, confine the stop rods and prevent them ~rom buckli~g.
Although the best mode contemplated for carryin~
out ~he present invention has been herein shown and described, it will be apparent that modification and varia-tion may be made without departing from what is regarded to be the subject matter o~ the invention.
, ~. . .
JFV:csa ~; :
" ,,.
. ' ,..
..
'~
.::
:' :-.
. . --10--'
Stop mechanism with telescopic members are shown in United States patents 2,479,838; 2,509,686; 2,627,985;
. . . . .
,~ .
~,, 55~3 2,840,244; and 3,097,749.
Another boom stop device of interest is the one shown in --United States patent 3,076,560. In this device two rods are pivotally connected to the boom. Each is received in a trunnion pivotally connected to the mast. A stop is fixed on the superstructure which is -,. :-.
engaged by the rod when the boom reaches its extreme upper position. ~
:~
Any or all of the previously mentioned stop devices may be equipped with some type of energy absorbing or energy dissipating `~' mechanisms. The purpose of ~hese mechanisms is to reduce the impact loadings encountered in stopping a recoiling boom. The energy absorbing ~`
devices commonly used include: springs, bumpers, and/or compressed air `
cushions.
SUMMARY 0~ T~IE INVENTION
According to the present invention, there is provided in a crane having a body and having a boom pivotally connected to the body, ; said crane having a stop rod pivotally connected to the boom and having a stop member mounted on the body, said crane having a guide sleeve, the improvement wherein said guide sleeve is pivotally mounted on the "`
body to receive the stop rod therein and is pivotal on the body by the ;
stop rod, said sleeve terminating near the stop member when the boom is in the extreme upper position to guide the outer end of the stop rod into engagement with the stop member.
In the preferred embodiment, the invention, a pair of stop rods are pivotally connected to the boom and a pair of stop units are , ~ , fixed to the body, or superstructure, of the crane, with an-elongated ;
sleeve is pivotally connected to the superstructure close to each fixed `
stop unit. As the boom reaches its extreme upper position, the stop '~
rods extend through the sleeves and into engagement with the fixed stop units. Since the sleeves are pivotally mounted on a fixed axis to the 3Q same body on which the stop units are secured, and since the sleeves ,..
~,, '.
:: :: `..
:~ :
~L04~593 :
,.:, , .:
`, extend into close proximity to the stop units, the stop rods are positively ; -guided, without risk of misalignment due to flexing of the crane membersJ
into engagement with the stop units. The stop rods act as columns in t compression when s~opping the upward movement of the boom, and the ~ sleeves prevent the columnar rods from buckling ~lder the load imposed ; by the boom. At the same time, the device of the present invention ~-' incorporates all the advantages of conventional telescopic boom stop devices.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings which illustrate an exemplary `
embodiment of the present invention:
Figure 1 is a side elevational view of a crane incor- r porating a boom stop.
Figure 2 is an enlarged view, taken as the view of Figure 1, of the stop mechanism. `
Figure 3 is a central section of the energy absorbing device utilized in the stop mechznis=, shown ~ust ' ::
''. ' . - 5 -` ~
~L04~S93 ~`
before impact o the stop rod as the boom approaches its -extreme upper position. -~
Figure 4 is a fragmentary plan view, taken on the - line 4-4 of ~igure 2, of the stop mechanism.
Figure 5 is a view in perspective of the guide sleeve mounting mechanism~
Figure 6 is a schematic perspective view o~ th~
stop mechanism.
DESCRIPTION OF THE PREFERRED EMlBODIMEl!~T "` .
. , .
There is shown in Figure 1 a crane 10 havin~ a superstructureO or bod~, 12 and a caxriert or chassis, ~4 The carrier 14 is shown with a frame 14a and an endless ~ ~ .
crawler track 14b mounted on sprockets 14c journaled in the ~rame, but it may, instead, comprise a ~rame with wheels.
; 15 The ~ody 12 ha~ a ~rame 12a for mounting much o~ the cran~
machiner~, a pedestal 12b on the frame or pivotally ....
mounting a boom 16, and a housing 12c secured to and enclosing ~he frame. The boom 16 is pivotally connected to the pedestal 12b on axis A for vertical swinging move- ;~
ment, and body 12 is pivotally mounted on the chassis 14 ,-for swinging movement about axis B. ;
A stop rod 18 is connected at one end to each ~;~
side of the boom 16 (at a poin~ C) for pivotal movement .: : .
with respect to the boom about horizontal axis Do It will be noted that each point C is spaced from the axis A
about which the boom swings on the body a distance R.
Thus, as the boom swings between a position on the ground .
~shown in dotted lines and indicated at 16') and a desired extreme upper position (shown in dotted lines and indi-cated at 16"), the point C follows a circular path P
, ' .' , .. . .
..
' ~04~93 : `
about axis A~ Consequently, the boom end o each stop rod 18 must move along the path P as the boom swings between the two eætreme positions 16' and 16".
A5 shown best in Figure 2, an elongated guide sleeve 20 for each stop rod 18 is mounted to the body, or superstructure, 12 for pivotal movement about a hoxizontal axis E which is spaced from the sleave and from the longi- ~:
tudinal axis F thereof~ Each sleeve receives ~he stop rod ~.-18 ~herein~ and the sleeves are long enough to support the ends of the rods opposite the boom ends in any position`
~o~ the boom between the two extreme positions 16' and 16".-A bracket 22 is wel~ed to the body rame 12a *or each sleeve 20, and a support brac~et 23 is secured to each bracket 22. Each suppork bracket has a pair o.~ upstanding 1~ ears 24. ~n ear 25 secured ~o the end of the guide sleeve 20 remote from the boom, is received between the ears 24 :and pivotally connected thereto by pin 26 which lies in the pivot axis E. Each stop rod 18 slides longitudinally in the sleeve 20 from an extended position in the sleeve when the boom is in the lower extreme position 16', to a telescopea position in the sleeve when ~he boom is in the upper extreme position 16". When the boom is in the latter position~ each stop rod and sleeve will lie in an axis G, and the distal, or free, end of the stop rod will extend from the end of the~sleeve ~which is open at both ends) remote from the boom.
A stop unit 28 is secured to the body, or .
superstructure 12a, on each axis G for engagement by the distal, or free end of each stop rod 18 when the boom i5 in the desired upper extreme position 16".
~41)593 ~ ::
As sho~n best in Figure 3, each stop unit has an outer casing 30 which is secured to the frame 12a of the body by a bracket 31. Each stop unit casing has a ring 32 secured in ~he lower, or remote, end thereof. A
shorter, smaller inner tube 34 has its lower, or remote, `; end secured inside the ring. The upper end of tube 34 is closed by plate 36 which has a central opening 38 ther~in.
An abutment plate 40~ having a dished forward face 42 to receive the rounded free end 44 of stop rod 18, is mounted on a disc 46 which is received in the open !'.
front end o casing 30~ A spring backing plate 48 is secured by spacer sleeve 50 to disc 46~ A small tube 52 ;~ extends through backing plate 48, disc 46, and abutment ; ~ `
plate 40 to terminate at its forward end in the center o~
the face 4~. Tube 52, which is secured to plate 40, disc 46 and plate 48, extends rearwardly through the opening 38 in plate 36, but is not secured to the plate 36. A washer 54, nut 56 and lock nut 58 are received on the tube in -~
sleeve 34, the washer in engagement with plate 36. The nuts, which are in threaded engagement with the tube, are drawn up again~t the washer to prevent forward movement of the tube 52 beyond the point whera disc ~6, which i9 secured to tube 52, is flush with the forwaxd end of casing 30.
A compression spring 60 is received in casin~ 30, over tube 34, and between rear ring 32 and spring backing plate 48. Thus, when the remote end 44 of stop rod 18 engages abubment plate 40 as the boom reaches its upper extreme position 16", the assembly of plate 40, disc 46, '''` ~.
--8-- ~ .
, ,,~
~4~S93 - spacer 50 and ~late 48 is forced into the casing 30, com- .. .
pressing spring 60 to absorb the impact of ~he elevating boom. After the spring is compressed to stop the boom, the stored energy of the sprin~ returns ~he head assembly (40, 46, 50 and 48) to the extended position with disc 46 flu.sh wi-th the end of casing 30O
.. ~
An artuator rod 62, having a head 640 is xe- ;
ceived in t~bé S2 of one of the stop units. A lever 66.is hel~ b~ bracket 68 and bolt 70, over ~he remote encl of casing 30 of that unit. Rod 62 extends thxough an opening in le~er 66 and is prevented from forward movement with respect t~exeto by washer 74, nut 76 and lock nut 7 spring 80, xeceived in an enlarged bore portion oE tubo 52 and engaged with head 64 of rod 62, urges rod 62 for-ward with hea~ ~4 protruding from face 42 of abutment plate 40. When -~he head 64 i5 engaged by stop rod 18, the '~
lever 66, which is biased away rom casing 30, is released. ~s the lever 66 moves away from casing 30, the spring biased switch 82, mounted on casing 30, is released to cut the power to the boom elevating mechanism~
In operation of the stop mechanism of the pre-sent invention, it should be noted that the stop rods 18 are maintained within the sleeves 20 in every position o~
; . the boom 16. As the boom is raised, the boom end of each stop rod 18 moves in the circular arc P by virtue of its pivotal connection to the boom. The stop rods 18 thus swing the sleev~s ~0 toward the axis G as the boom approaches its ex~reme UppeL position 16". As the distal end of the stop rods reach the abutment plates 40 of the stop units, the shock of the impact is absorbed by the _g_ , .,. . ,; . ~.
{)593 spring 60. At ~he same time, the rod 62 is actuatea to operate switch 82 and thereby shut off the boom elevating `~
machinery.
Thus it wil~ be seen that a simple, effective telescopic boom stop mechanism is provided in which stop rods act as column in compression as they tran~er the impact of the elevating boom to shock absorbing stop units. `~
The columns defined by the stop rods are guided in~o pro per contact with the units by the sleeves by virtue of t~eix offset pivot axis. At the same time, the guide sleeves, which themselves do not take any of the load of the elevating boom, confine the stop rods and prevent them ~rom buckli~g.
Although the best mode contemplated for carryin~
out ~he present invention has been herein shown and described, it will be apparent that modification and varia-tion may be made without departing from what is regarded to be the subject matter o~ the invention.
, ~. . .
JFV:csa ~; :
" ,,.
. ' ,..
..
'~
.::
:' :-.
. . --10--'
Claims (7)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In a crane having a body and having a boom pivotally connected to the body, said crane having a stop rod pivotally connected to the boom and having a stop mem-ber mounted on the body, said crane having a guide sleeve, the improvement wherein said guide sleeve is pivotally mounted on the body to receive the stop rod therein and is pivotal on the body by the stop rod, said sleeve termina-ting near the stop member when the boom is in the extreme upper position to guide the outer end of the stop rod into engagement with the stop member.
2. The mechanism of claim 1 wherein the stop member has means yieldable under the impact of the stop rod to absorb the energy thereof.
3. The mechanism of claim 1 wherein said sleeve is elongated to support the stop rod during movement of the boom through a wide range.
4. In a crane having a body and having a boom pivotally connected to the body, mechanism for limiting the upward movement of the crane comprising in combina-tion, a stop unit mounted in a fixed position on the body, a guide sleeve mounted adjacent the stop unit and pivotal about an axis fixed with respect to said stop unit, a stop rod pivotally connected to said boom and received in the guide sleeve for guidance into contact with the stop unit as the boom is elevated into its ex-treme upper position.
5. In a crane having a body and having a boom pivotally connected to the body, mechanism for limiting pivotal movement of the boom beyond an extreme upper posi-tion comprising in combination: a stop rod pivotally connected at a point to the boom, a stop unit mounted on the body in an axis extending through said point when the boom is in its extreme upper position, a guide sleeve pivotally mounted on the body adjacent said stop unit, said sleeve receiving said stop rod and pivotal on the body by the stop rod, said sleeve lying in said axis with the stop rod extending therethrough into engagement with the stop unit when the boom is in the upper extreme posit-ion.
6. In a crane having a body and having a boom pivotally connected to the body on a first axis, mechanism for limiting pivotal movement of the boom beyond an ex-treme upper position comprising in combination: a stop rod pivotally connected at a point to the boom, a stop unit mounted on the body in a second axis extending through said point when the boom is in its extreme upper position, said second axis lying in a plane transverse to the plane of said first axis, a guide sleeve mounted on the body for pivotal movement about a third axis parallel to said first axis, said third axis spaced from said second axis, said sleeve receiving said stop rod in any position of said boom and pivotal by the stop rod into said second axis when the boom is raised to its extreme upper posi-tion.
7. In a crane having a body and having a boom pivotally connected to the body for swinging movement to a desired upper limit of movement, said boom having a stop rod pivotally connected thereto at a point, an elongated stop mechanism secured to said body, said stop mechanism aligned on a first axis fixed with respect to said body, said first axis passing through the point on the boom at which said stop rod is pivotally connected. when the boom is in the desired upper limit position, and a guide tube pivotally mounted on a second. axis fixed with respect to said body to receive the stop rod and maintain the rod in telescopic relationship, said second axis spaced. from said first axis and said guide tube swung into said first axis by the stop rod when the boom reaches the desired upper limit of travel.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US65034076A | 1976-01-19 | 1976-01-19 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1040593A true CA1040593A (en) | 1978-10-17 |
Family
ID=24608491
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA262,218A Expired CA1040593A (en) | 1976-01-19 | 1976-09-28 | Stop for crane boom |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPS5288954A (en) |
| BR (1) | BR7607243A (en) |
| CA (1) | CA1040593A (en) |
| IT (1) | IT1074733B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5912091A (en) * | 1982-07-13 | 1984-01-21 | 石川島播磨重工業株式会社 | Jib crane |
| JPS61206598U (en) * | 1985-06-17 | 1986-12-26 |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2509686A (en) * | 1945-07-05 | 1950-05-30 | William M Huston | Boom stop for load handling machines |
| US3076560A (en) * | 1961-04-24 | 1963-02-05 | Thew Shovel Co | Retractible mast and boom stop |
-
1976
- 1976-09-28 CA CA262,218A patent/CA1040593A/en not_active Expired
- 1976-10-11 IT IT5166976A patent/IT1074733B/en active
- 1976-10-25 JP JP12814976A patent/JPS5288954A/en active Pending
- 1976-10-27 BR BR7607243A patent/BR7607243A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5288954A (en) | 1977-07-26 |
| IT1074733B (en) | 1985-04-20 |
| BR7607243A (en) | 1977-09-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6343661B1 (en) | Suspension system for a work vehicle | |
| US4288034A (en) | Boom shock and tilt system | |
| RU2526318C2 (en) | Landing gear bogie stop | |
| CN210829314U (en) | Gate-type fore support with buffering energy-absorbing device | |
| CA1326356C (en) | Side wing snow plow assembly with rotation preventing link mounted piston rod slide bearing | |
| CA1182493A (en) | Assist assembly for cab structure | |
| CA2453371C (en) | Two directional crossing gate arm protection assembly | |
| CN108385764A (en) | A kind of novel excavator cab protecting against shock vibration absorber | |
| US4685888A (en) | Outboard motor support | |
| CA1040593A (en) | Stop for crane boom | |
| JPS60248B2 (en) | Spring suspension vehicle seat | |
| US4270663A (en) | Stop for crane boom | |
| CN208236451U (en) | A kind of mine down-hole operation safety protection bracket | |
| US4147308A (en) | Roller mill | |
| US5000385A (en) | Spray boom breakaway apparatus | |
| CN108891311B (en) | Mine car seat is prevented to military vehicle | |
| US4239168A (en) | Retaining device for an obstacle rail | |
| KR20200015965A (en) | Self-restoration type semi-rigid crash barrier | |
| US4153117A (en) | Cushion dozer with three point attachment support | |
| US3086742A (en) | Seat suspension | |
| CN107988938A (en) | It is a kind of to place firm bridge height limiter | |
| CN210591330U (en) | Alloy car door support | |
| CA2313900C (en) | Suspension system for a work vehicle | |
| CN213653203U (en) | Cast-in-place bridge body protector of building a bridge | |
| CN212893554U (en) | Safety protection device for crown block driver |