CA2143368A1 - Emergency cable brake - Google Patents
Emergency cable brakeInfo
- Publication number
- CA2143368A1 CA2143368A1 CA 2143368 CA2143368A CA2143368A1 CA 2143368 A1 CA2143368 A1 CA 2143368A1 CA 2143368 CA2143368 CA 2143368 CA 2143368 A CA2143368 A CA 2143368A CA 2143368 A1 CA2143368 A1 CA 2143368A1
- Authority
- CA
- Canada
- Prior art keywords
- cable
- housing structure
- brake apparatus
- gripping means
- improved emergency
- 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.)
- Abandoned
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Abstract
An emergency cable brake type apparatus having a housing structure. A cable gripping device includes a first portion thereof immovably secured within and to such housing structure and a second portion thereof pivotably secured within and to the housing structure. The second portion of such cable gripping device being cooperable with the first portion of such cable gripping device for gripping and holding such cable when the tension on such cable is suddenly removed. A trigger mechanism has a first portion thereof rotatably secured within such housing structure for sensing any undesirable and sudden acceleration of such cable. A second portion of such trigger mechanism is pivotably connected to a predetermined surface of the first portion of the trigger mechanism. Such second portion of the trigger mechanism engages a third portion of s trigger mechanism which is pivotably connected to the housing structure and engagable with such cable gripping device for releasing the cable gripping device so that further free fall of such cable is stopped.
Description
~143368 -E~R~NCY CABLE BRAKE
FIELD OF THE lNV~NlION
The present invention relates, in general, to suspension type cables which will normally be subjected to a substantially constant tension being applied to them during service thereby increasing the chances of these suspension cables becoming broken due at least in part to such constant tension being applied to them over an extended period of time and, more particularly, this invention relates to an improved emergency cable brake type apparatus which is specifically designed to both quickly seize and then retain such suspension cable in the event that such suspension cable should become broken and in this manner substantially minimize any detrimental and/or potentially hazardous sudden movements of the suspension cable and, still even more specifically, the instant invention relates to an improved emergency cable brake type apparatus which will both seize and hold the suspension cable portion of a balanced weight assembly that provides the requisite amount of constant tension on both the overhead messenger wire and contact wire portions of an overhead suspended catenary system that supplies the electrical energy necessary to operate certain known types of passenger transit railway vehicles in the event at least one of such messenger wire portion or such contact wire portion of such catenary system should become broken for any reason.
BACKGROUND OF THE lNv~N~lION
It is generally well recognized in the suspension cable art, that there are a number of applications in which steel and/or other type metal cables will be subjected to a more or less constant tension being applied to them during their normal service. The - 21~3368 steel cables which are attached to elevator cars for enabling the movement of these cars between adjacent floors in a building and the cable which forms at least a portion of the balanced weight assembly utilized to maintain a substantially constant tension on both the messenger wire portion and the contact wire portion of an overhead suspended catenary system that enables the necessary electrical energy to be delivered to certain known types of passenger transit type railway vehicles are only two examples of such cables, presently known by applicant, that will be subjected to a relatively constant tension being applied to them during service.
It is likewise well known, for example, that these elevator car suspension cables must always possess at least the capability of supporting not only the overall gross weight of a particular elevator car but, also, these suspension cables are quite often required to support the additional weight of one or more passengers and/or some form of freight which is being transported therein.
Consequently, even though these elevator car suspension cables are subjected to a relatively constant tension, the tension that is being applied to them during their normal operation will, obviously, vary from time to time due to both the number and the weight of such passengers and/or the weight of such freight being carried by the elevator car.
On the other hand, the balanced weight assembly which is normally utilized to maintain the tension on each of the messenger wire portion and the contact wire portion of an overhead suspended catenary system will normally provide a substantially constant tension. The prior art type balanced weight assemblies which are used in this particular application may include either an integral ~1~3368 type weight portion or a stack of individual type weight portions.
In either case these weight portions are usually both suspended from and supported by a steel cable which has a predetermined diameter.
Additionally, the suspension cable is, normally, looped through a pulley system connected to a yoke member which in turn is connected to one end of both the messenger wire portion and the contact wire portion of the catenary system.
The specified weight ratio that is provided between the more or less typical balanced weight assembly known to be in use at the present time and the catenary system which is suspended overhead will, generally, be on the order of approximately 1:3.
Furthermore, in this known type of catenary system, either the integral type weight portion or the stack of individual type weight portions of such balanced weight assembly will be essentially free to travel in each of an upwardly and downwardly direction. Such upward or downward movement of such balanced weight assembly will readily compensate for either the contraction or the expansion of both the messenger wire portion and the contact wire portion of such overhead suspended catenary system. The noted contraction and expansion of such catenary system, normally, being encountered due to the fluctuations in the temperature.
Additionally, in each of the applications discussed above, the suspension cable is being subjected constantly to a rather large amount of flexing. Such flexing of the cable will, in general, tend to cause a certain amount of fatigue in the cable. This will be especially the case over an extended period of time.
In addition, in the application for providing a substantially constant tension on an overhead suspended catenary system, the suspension cable for the balanced weight assembly portion of such catenary system is more often than not constantly exposed to the outdoor elements during service.
In one particular overhead suspended catenary system that is connected to supply the electrical energy required for a passenger transit type railway vehicle installation, which is known by the applicant to be in operation at the present time, the constant tension that is being maintained on such messenger wire portion of such catenary system is on the order of approximately 4,000 lbs.
and the constant tension that is being maintained on the contact wire portion of such overhead catenary system is on the order of approximately 3,000 lbs.
Therefore, in order to accomplish these constant tension values the overall weight of the weight stack portion of such balanced weight assembly will be 1/3 of about 7,000 lbs. or on the order of about 2,333 lbs.
It is, likewise, known by the applicant that in such overhead suspended catenary system discussed above, the weight stack portion of such balanced weight assembly is movably disposed at a position located a few feet above the ground level. Consequently, prior to the development of the present invention, if an undesirable event should occur in which both of such messenger wire portion and the contact wire portion of such suspended catenary system should become broken, then at a minimum the weight stack portion of such balanced weight assembly would be capable of free falling down to the ground.
Obviously, should the weight stack portion of the balanced weight assembly fall to the ground a considerable amount of damage could occur to the pole during the fall as well as to the weights ~1~3368 which form the individual weight stack portion itself. Of even more importance, it is conceivable that these weights could cause either a serious or possibly even a fatal injury to anyone who might happen to be in their way as they are tumbling down to the ground.
SUMMARY OF THE lNV~NllON
In a first aspect, the present invention provides an improved emergency cable braking type apparatus which is capable of being utilized in a number of specific, but different, applications. The emergency cable brake apparatus, of this invention, includes a housing structure. A cable gripping means includes a first portion thereof immovably secured within and to such housing structure and has a second portion thereof pivotably secured within and to such housing structure. The second portion of such cable gripping means is designed to cooperate with such first portion of the cable gripping means in a manner to both grip and hold such cable when the tension on such cable is suddenly removed. There is a trigger means having a first portion thereof rotatably secured within such housing structure for sensing any undesirable and relatively sudden acceleration of such cable. A second portion of such trigger means is pivotably connected to a predetermined surface of such first portion of the trigger means. This second portion of such trigger means engages a third portion of the trigger means which is pivotably connected to such housing structure and is engagable with the cable gripping means for releasing such cable gripping means into a position such that any further free fall of such cable is stopped.
In a second aspect of the present invention, there is provided in an overhead suspended catenary system, having both a messenger ~143368 -wire portion and a contact wire portion connected at one end thereof to a yoke-like member and a balanced weight assembly connected to said yoke and a pole member to provide a predetermined amount of substantially constant tension on such messenger wire portion and such contact wire portion of such catenary system, the improvement therewith of a cable type brake apparatus as described above.
OBJECTS OF THE lNv~N~l~ION
It is, therefore, one of the primary objects of the present invention to provide an improved emergency cable brake type apparatus which is effective in both seizing and holding a suspension type cable upon determining a break has occurred.
Another object of the present invention is to provide an improved emergency cable brake type apparatus which can be readily adapted to a number of different applications in which a suspension type cable is utilized.
Still another object of the present invention is to provide an improved emergency cable brake type apparatus which is relatively simple to install.
Yet still another object of the present invention is to provide an improved emergency cable brake type apparatus which will require a m; n; m~ 1 amount of maintenance.
A still further object of the present invention is to provide an improved emergency cable brake type apparatus which will be relatively inexpensive to manufacture.
It is an additional object of the present invention to provide an improved emergency cable brake type apparatus which is particularly well suited for use with the suspension cable portion of a balanced weight assembly that is designed in such a manner so `- 21~ 68 as to maintain a substantially constant tension on both a messenger wire portion and a contact wire portion of an overhead catenary system that supplies the electrical energy required to operate certain types of passenger transit vehicles.
A further object of the present invention is to provide an improved emergency cable brake type apparatus which can be rather easily retrofitted to an existing suspension cable portion of a balanced weight assembly forming a part of an overhead suspended catenary system.
Still yet another object of the present invention is to provide an improved emergency cable brake type apparatus which can be easily adapted to a number of different applications that may require the use of a number of different cable sizes.
A further object of the present invention is to provide an improved emergency cable brake type apparatus which includes a self-locking feature incorporated therein.
In addition to the several objects and advantages of the present invention that have been discussed in some detail above, it is conceivable that various additional objects and advantages of the improved cable type brake apparatus will become more readily apparent to those persons who are skilled in the relevant cable braking art from the more detailed description of the invention which follows, particularly, when such detailed description is taken in conjunction with the attached drawing Figures and with the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a perspective view which illustrates a presently preferred embodiment of a housing structure of an emergency cable brake type apparatus according to a presently preferred embodiment of the invention;
Figure 2 is a side elevation view of a presently preferred embodiment of the emergency cable brake type apparatus of the present invention with the cover removed from the housing structure;
Figure 3 is a perspective view which illustrates a presently preferred embodiment of the emergency cable brake type apparatus illustrated in Figures 1 and in a position before it has been triggered to seize a cable and with the cover removed;
Figure 4 is another perspective view of the emergency cable brake type apparatus illustrated in Figures 1 and 2; and Figure 5 is a schematic diagram which illustrates the present invention as it is used in a suspension cable portion of a balanced weight assembly that is designed in such a manner so as to maintain a substantially constant tension on both a messenger wire portion and a contact wire portion of an overhead catenary system that supplies the electrical energy required to operate certain types of passenger transit vehicles.
BRIEF DESCRIPTION OF THE PRESENTLY
PREFERRED EMBODIMENTS OF THE lNV~NlION
Prior to proceeding to the more detailed description of the present invention, it should be noted here that, for the sake of clarity, identical components which have identical functions have been identified with identical reference numerals throughout the several views illustrated in the drawings.
Additionally, it should be noted here that even though, for the purposes of understAn~;ng the invention, such improved emergency cable brake type apparatus will be described in detail as it will relate specifically to use in a suspension cable portion of a balanced weight assembly that is designed in such a manner so as to maintain a substantially constant predetermined tension on both a messenger wire portion and a contact wire portion of an overhead suspended catenary system that is provided in order to supply the electrical energy requirements for the operation of certain known types of passenger transit vehicles, the applicant, also, contemplates use of the present invention in a number of other cable brake type applications and these other applications are, likewise, considered to be within the spirit of the instant invention and the broad scope of the claims.
Now reference is made, more particularly, to Figure 5 of the drawing Figures. Illustrated therein is one end of a catenary system, generally designated 10. Catenary system 10 is suspended overhead and is known to be in use in a mass transit installation at the present time. As is known, such overhead catenary system is provided in this installation to supply the necessary electrical energy to the railway type passenger transit vehicles.
Such catenary system 10 includes each of a messenger wire portion 12 and a contact wire portion 14. One end of each of the messenger wire portion 12 and such contact wire portion 14 is attached to a plate-like yoke member 16 adjacent respective ends thereof.
In order to suspend such catenary system 10 overhead, there is provided a pole member 18, which has a portion of a balanced weight assembly, generally designated, 20 attached thereto adjacent the upper end thereof. Such balanced weight assembly 20 includes at least one and, preferably, a plurality of pulley members 22 (three such pulley members are illustrated) and their associated brackets 24 around which a cable 26 is strung. A first end 28 of - 21~3368 such cable 26 is secured to the yoke member 16 at a predetermined point located intermediate the one end of such messenger wire portion 12 and the one end of such contact wire portion 14 which are attached to such respective ends of the yoke member 16.
Attached to the cable 26, adjacent the second end 30 thereof is a weight stack portion 32. Such weight stack portion 32 of the balanced weight assembly 20 provides a predetermined amount of substantially constant tension to be applied to such catenary system 10.
Now reference is made, more particularly, to Figures 1 through 4 of the drawings. Illustrated therein is one of the presently preferred embodiments of the invention in which such improved cable type brake apparatus, generally designated, 40 is pivotally attached to such pole 18. The cable brake apparatus 40 is disposed on the pole 18 at a point located intermediate that portion of such balanced weight assembly 20 attached to the upper end portion of such pole 18 and the weight stack portion 32. In this embodiment of the invention, the pivotal attachment of the cable brake apparatus 40 to the pole 18 is achieved by at least one and,preferably, by a pair of mounting brackets 34 (upper and lower) attached to such pole 18 and a bolt 36 disposed through both such upper and lower mounting brackets 34 and the housing structure 38 of such emergency cable brake apparatus 40.
In addition to the housing structure 38, such emergency cable brake apparatus 40 further includes a cable gripping means, generally designated 50. Cable gripping means 50 has a first portion 42 thereof immovably secured within and to such housing structure 38 and a second portion 44 thereof pivotably secured within and to the housing structure 38. The second portion 44 of ~1~3368 such cable gripping means 50 being cooperable with such first portion 42 of the cable gripping means 50 for both gripping and holding the cable 26 when such tension on such cable 26 is suddenly removed.
The final essential component of the emergency cable brake 40, according to the present invention, is a trigger means, generally designate 60, having a first portion 46 thereof rotatably secured within such housing structure 38 for sensing any undesirable and sudden acceleration of such cable 26. A second portion 48 of such trigger means 60 is pivotably connected to a predetermined surface 52 of such first portion 46 of the trigger means 60. Such second portion 48 of the trigger means 60 engages a third portion 54 of such trigger means 60 which is pivotably connected to the housing structure 38 and engagable with such cable gripping means 50 for releasing such cable gripping means 50 so that further free fall of such cable 26 is stopped.
According to the presently preferred embodiment of the invention of the improved emergency cable brake apparatus 40, the housing structure 38 includes a pair of slot-like openings 56 and 58 formed therein to enable such cable 26 to pass through such housing structure 38. Additionally, in this embodiment, such housing structure 38 further includes a cover member 62 which is at least one of removable from such housing structure 38 and pivotable away from such housing structure 38 to enable the cable brake apparatus 40 to be installed after such cable 26 has been installed.
The improved emergency cable brake apparatus 40 further includes a guide pulley 64 rotatably secured within and to such housing structure 38 closely adjacent a predetermined one 56 of the pair of slot-like openings 56 and 58 for guiding such cable 26 through the housing structure 38 in a desired path.
The first portion 42 of such cable gripping means 50 includes a groove-like portion 66 disposed closely adjacent a first side of such cable 26 in the presently preferred embodiment and the second portion 44 of such cable gripping means 50 is at least one cam-like member having a predetermined surface 68 engagable with an opposed second side of such cable 26. Preferably, the predetermined surface 68 includes a plurality of knurled surfaces.
In addition, it is also presently preferred that such second portion 44 of such cable gripping means 50 includes a pair of cam-like members 44 and that the cable brake apparatus 40 further includes a means 70 for connecting such at least one cam-like member to a second one of such pair of cam-like members 44.
In the embodiment being described, such first portion 46 of the trigger means 60 is, preferably, a pulley member 46 engaged with one side of such cable 26. The second portion 48 of such trigger means 60 is a plurality of paddle-like members 48 pivotably secured to one surface 52 of such pulley member 46 and the third portion 54 of such trigger means 60 is a release arm 54 having a portion 72 thereof engaged in a slot formed in a portion of such cable gripping means 60.
As discussed above, the function of the Balance Weight Assembly is to apply a constant tension to the contact and messenger wires during changing atmospheric conditions, i.e.
ambient temperature changes. It accomplishes this via a balance weight stack which applies a constant force to the contact and messenger wire. During normal operation, due to contraction and expansion, the counter weight stack moves up and down according to ~113~68 the temperature of the contact and messenger wires. Under cold conditions, it is in the upper position and during hot conditions, the lower position. This assembly allows the tension of the contact and messenger wires to be constant under varying ambient temperatures. The cable brake, during normal operation, allows for the cable to pass through the unit without resistance. The tripping mechanism monitors the acceleration of the cable. When the messenger and/or contact wires fail, the tension load releases and causes the weights to free-fall to the ground. The cable brake is used to prevent the weights from impacting the ground. The cable brake consists of two major components. One, the mechanism that senses the acceleration of the wire rope, and two, the gripping mechanism that stops the cable. Figures two and three show the trigger mechanism, idler pulley, release arm, cams, linkage, wedge block, ice scrapers, and reset handles. All of which is mounted in a housing. Under normal operating conditions, the cable moves up and down through the assembly turning both the tripping pulley and the idler pulley. Excessive ice is removed from the cable via two ice scrapers mounted on the top and bottom.
When a contact and/or messenger wire failure occurs, the acceleration of the cable through the unit is sensed by the trigger mechanism. The trigger mechanism, in conjunction with the release arm, frees the cams and allows them to fall into place and engage the cable. The cam movement and the trigger mechanism is based on gravity, which removes any need for adjustment and also minimizes the chances of product failure over its lifetime.
In operation, the trigger mechanism senses the down acceleration of the cable which cause centrifugal forces to act on a set of paddles attached to the trigger pulley. As the cable ~1 13~68 acceleration increases from zero to 1-G, the paddles overcome gravitational forces and swing outward. The centrifugal energy of the paddles is transferred to the release arm through impacts on the release arm pegs. The release arm pivots out from the cam slot and frees the cams. The cable is gripped by two linked cams that engage the cable after being released by the trigger. The amount of cam-cable engagement, the cam material, and the dimensional profile of the cams lend to the amount of friction generated by the cams. The amount of friction required to stop the weight stack is dependent on the speed in which the mechanism is triggered and the condition of the cable.
Additionally, the present invention has the capability for ice removal provided by the two pulleys. This is due to the slight offset path of the cable routing through the cable brake. The cable brake is self-aligning to the cable due to the size of the idler pulley. The cable brake can be retrofitted into any existing balance weight assembly with minimal effort. And, since the major acting force on the components is gravity, mi n i m~ 1 maintenance effort is required.
It is evident from the above description of the invention that the emergency cable brake prevents the balance weight assembly's counter weights from falling to the ground during a contact or messenger wire failure. This prevents pole foundation damage and minimizes overhead cantenary hardware damage due to the effects of impact loads of the free-falling counter-balance weight. The invention also provides a relatively maintenance-free component which is easy to install and reset once tripped. This allows installation crews, inspection crews and repair crews to minimize their efforts during operation of the cable brake. Further, the - . ~143368 invention will minimize the damage to the pulley cable when the messenger and/or contact wires have failed. ~ini~izing the damage to the cable caused by friction reduces the hazard of this failing during operation. Finally, the invention provides a positive, swift means of sensing the abnormally high acceleration of the weights but ignore normal movement. This allows the cable brake to react to the falling weights quickly, reducing the amount of energy the cable brake must dissipate.
Although a number of presently preferred and various alternative embodiments of the instant invention have been described in detail above in conjunction with the several drawing Figures, it should be noted and understood that various other modifications and adaptations of the improved emergency cable brake type apparatus can be envisioned by those persons who are skilled in this particular art without departing from either the spirit of the invention or the scope of the appended claims.
FIELD OF THE lNV~NlION
The present invention relates, in general, to suspension type cables which will normally be subjected to a substantially constant tension being applied to them during service thereby increasing the chances of these suspension cables becoming broken due at least in part to such constant tension being applied to them over an extended period of time and, more particularly, this invention relates to an improved emergency cable brake type apparatus which is specifically designed to both quickly seize and then retain such suspension cable in the event that such suspension cable should become broken and in this manner substantially minimize any detrimental and/or potentially hazardous sudden movements of the suspension cable and, still even more specifically, the instant invention relates to an improved emergency cable brake type apparatus which will both seize and hold the suspension cable portion of a balanced weight assembly that provides the requisite amount of constant tension on both the overhead messenger wire and contact wire portions of an overhead suspended catenary system that supplies the electrical energy necessary to operate certain known types of passenger transit railway vehicles in the event at least one of such messenger wire portion or such contact wire portion of such catenary system should become broken for any reason.
BACKGROUND OF THE lNv~N~lION
It is generally well recognized in the suspension cable art, that there are a number of applications in which steel and/or other type metal cables will be subjected to a more or less constant tension being applied to them during their normal service. The - 21~3368 steel cables which are attached to elevator cars for enabling the movement of these cars between adjacent floors in a building and the cable which forms at least a portion of the balanced weight assembly utilized to maintain a substantially constant tension on both the messenger wire portion and the contact wire portion of an overhead suspended catenary system that enables the necessary electrical energy to be delivered to certain known types of passenger transit type railway vehicles are only two examples of such cables, presently known by applicant, that will be subjected to a relatively constant tension being applied to them during service.
It is likewise well known, for example, that these elevator car suspension cables must always possess at least the capability of supporting not only the overall gross weight of a particular elevator car but, also, these suspension cables are quite often required to support the additional weight of one or more passengers and/or some form of freight which is being transported therein.
Consequently, even though these elevator car suspension cables are subjected to a relatively constant tension, the tension that is being applied to them during their normal operation will, obviously, vary from time to time due to both the number and the weight of such passengers and/or the weight of such freight being carried by the elevator car.
On the other hand, the balanced weight assembly which is normally utilized to maintain the tension on each of the messenger wire portion and the contact wire portion of an overhead suspended catenary system will normally provide a substantially constant tension. The prior art type balanced weight assemblies which are used in this particular application may include either an integral ~1~3368 type weight portion or a stack of individual type weight portions.
In either case these weight portions are usually both suspended from and supported by a steel cable which has a predetermined diameter.
Additionally, the suspension cable is, normally, looped through a pulley system connected to a yoke member which in turn is connected to one end of both the messenger wire portion and the contact wire portion of the catenary system.
The specified weight ratio that is provided between the more or less typical balanced weight assembly known to be in use at the present time and the catenary system which is suspended overhead will, generally, be on the order of approximately 1:3.
Furthermore, in this known type of catenary system, either the integral type weight portion or the stack of individual type weight portions of such balanced weight assembly will be essentially free to travel in each of an upwardly and downwardly direction. Such upward or downward movement of such balanced weight assembly will readily compensate for either the contraction or the expansion of both the messenger wire portion and the contact wire portion of such overhead suspended catenary system. The noted contraction and expansion of such catenary system, normally, being encountered due to the fluctuations in the temperature.
Additionally, in each of the applications discussed above, the suspension cable is being subjected constantly to a rather large amount of flexing. Such flexing of the cable will, in general, tend to cause a certain amount of fatigue in the cable. This will be especially the case over an extended period of time.
In addition, in the application for providing a substantially constant tension on an overhead suspended catenary system, the suspension cable for the balanced weight assembly portion of such catenary system is more often than not constantly exposed to the outdoor elements during service.
In one particular overhead suspended catenary system that is connected to supply the electrical energy required for a passenger transit type railway vehicle installation, which is known by the applicant to be in operation at the present time, the constant tension that is being maintained on such messenger wire portion of such catenary system is on the order of approximately 4,000 lbs.
and the constant tension that is being maintained on the contact wire portion of such overhead catenary system is on the order of approximately 3,000 lbs.
Therefore, in order to accomplish these constant tension values the overall weight of the weight stack portion of such balanced weight assembly will be 1/3 of about 7,000 lbs. or on the order of about 2,333 lbs.
It is, likewise, known by the applicant that in such overhead suspended catenary system discussed above, the weight stack portion of such balanced weight assembly is movably disposed at a position located a few feet above the ground level. Consequently, prior to the development of the present invention, if an undesirable event should occur in which both of such messenger wire portion and the contact wire portion of such suspended catenary system should become broken, then at a minimum the weight stack portion of such balanced weight assembly would be capable of free falling down to the ground.
Obviously, should the weight stack portion of the balanced weight assembly fall to the ground a considerable amount of damage could occur to the pole during the fall as well as to the weights ~1~3368 which form the individual weight stack portion itself. Of even more importance, it is conceivable that these weights could cause either a serious or possibly even a fatal injury to anyone who might happen to be in their way as they are tumbling down to the ground.
SUMMARY OF THE lNV~NllON
In a first aspect, the present invention provides an improved emergency cable braking type apparatus which is capable of being utilized in a number of specific, but different, applications. The emergency cable brake apparatus, of this invention, includes a housing structure. A cable gripping means includes a first portion thereof immovably secured within and to such housing structure and has a second portion thereof pivotably secured within and to such housing structure. The second portion of such cable gripping means is designed to cooperate with such first portion of the cable gripping means in a manner to both grip and hold such cable when the tension on such cable is suddenly removed. There is a trigger means having a first portion thereof rotatably secured within such housing structure for sensing any undesirable and relatively sudden acceleration of such cable. A second portion of such trigger means is pivotably connected to a predetermined surface of such first portion of the trigger means. This second portion of such trigger means engages a third portion of the trigger means which is pivotably connected to such housing structure and is engagable with the cable gripping means for releasing such cable gripping means into a position such that any further free fall of such cable is stopped.
In a second aspect of the present invention, there is provided in an overhead suspended catenary system, having both a messenger ~143368 -wire portion and a contact wire portion connected at one end thereof to a yoke-like member and a balanced weight assembly connected to said yoke and a pole member to provide a predetermined amount of substantially constant tension on such messenger wire portion and such contact wire portion of such catenary system, the improvement therewith of a cable type brake apparatus as described above.
OBJECTS OF THE lNv~N~l~ION
It is, therefore, one of the primary objects of the present invention to provide an improved emergency cable brake type apparatus which is effective in both seizing and holding a suspension type cable upon determining a break has occurred.
Another object of the present invention is to provide an improved emergency cable brake type apparatus which can be readily adapted to a number of different applications in which a suspension type cable is utilized.
Still another object of the present invention is to provide an improved emergency cable brake type apparatus which is relatively simple to install.
Yet still another object of the present invention is to provide an improved emergency cable brake type apparatus which will require a m; n; m~ 1 amount of maintenance.
A still further object of the present invention is to provide an improved emergency cable brake type apparatus which will be relatively inexpensive to manufacture.
It is an additional object of the present invention to provide an improved emergency cable brake type apparatus which is particularly well suited for use with the suspension cable portion of a balanced weight assembly that is designed in such a manner so `- 21~ 68 as to maintain a substantially constant tension on both a messenger wire portion and a contact wire portion of an overhead catenary system that supplies the electrical energy required to operate certain types of passenger transit vehicles.
A further object of the present invention is to provide an improved emergency cable brake type apparatus which can be rather easily retrofitted to an existing suspension cable portion of a balanced weight assembly forming a part of an overhead suspended catenary system.
Still yet another object of the present invention is to provide an improved emergency cable brake type apparatus which can be easily adapted to a number of different applications that may require the use of a number of different cable sizes.
A further object of the present invention is to provide an improved emergency cable brake type apparatus which includes a self-locking feature incorporated therein.
In addition to the several objects and advantages of the present invention that have been discussed in some detail above, it is conceivable that various additional objects and advantages of the improved cable type brake apparatus will become more readily apparent to those persons who are skilled in the relevant cable braking art from the more detailed description of the invention which follows, particularly, when such detailed description is taken in conjunction with the attached drawing Figures and with the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a perspective view which illustrates a presently preferred embodiment of a housing structure of an emergency cable brake type apparatus according to a presently preferred embodiment of the invention;
Figure 2 is a side elevation view of a presently preferred embodiment of the emergency cable brake type apparatus of the present invention with the cover removed from the housing structure;
Figure 3 is a perspective view which illustrates a presently preferred embodiment of the emergency cable brake type apparatus illustrated in Figures 1 and in a position before it has been triggered to seize a cable and with the cover removed;
Figure 4 is another perspective view of the emergency cable brake type apparatus illustrated in Figures 1 and 2; and Figure 5 is a schematic diagram which illustrates the present invention as it is used in a suspension cable portion of a balanced weight assembly that is designed in such a manner so as to maintain a substantially constant tension on both a messenger wire portion and a contact wire portion of an overhead catenary system that supplies the electrical energy required to operate certain types of passenger transit vehicles.
BRIEF DESCRIPTION OF THE PRESENTLY
PREFERRED EMBODIMENTS OF THE lNV~NlION
Prior to proceeding to the more detailed description of the present invention, it should be noted here that, for the sake of clarity, identical components which have identical functions have been identified with identical reference numerals throughout the several views illustrated in the drawings.
Additionally, it should be noted here that even though, for the purposes of understAn~;ng the invention, such improved emergency cable brake type apparatus will be described in detail as it will relate specifically to use in a suspension cable portion of a balanced weight assembly that is designed in such a manner so as to maintain a substantially constant predetermined tension on both a messenger wire portion and a contact wire portion of an overhead suspended catenary system that is provided in order to supply the electrical energy requirements for the operation of certain known types of passenger transit vehicles, the applicant, also, contemplates use of the present invention in a number of other cable brake type applications and these other applications are, likewise, considered to be within the spirit of the instant invention and the broad scope of the claims.
Now reference is made, more particularly, to Figure 5 of the drawing Figures. Illustrated therein is one end of a catenary system, generally designated 10. Catenary system 10 is suspended overhead and is known to be in use in a mass transit installation at the present time. As is known, such overhead catenary system is provided in this installation to supply the necessary electrical energy to the railway type passenger transit vehicles.
Such catenary system 10 includes each of a messenger wire portion 12 and a contact wire portion 14. One end of each of the messenger wire portion 12 and such contact wire portion 14 is attached to a plate-like yoke member 16 adjacent respective ends thereof.
In order to suspend such catenary system 10 overhead, there is provided a pole member 18, which has a portion of a balanced weight assembly, generally designated, 20 attached thereto adjacent the upper end thereof. Such balanced weight assembly 20 includes at least one and, preferably, a plurality of pulley members 22 (three such pulley members are illustrated) and their associated brackets 24 around which a cable 26 is strung. A first end 28 of - 21~3368 such cable 26 is secured to the yoke member 16 at a predetermined point located intermediate the one end of such messenger wire portion 12 and the one end of such contact wire portion 14 which are attached to such respective ends of the yoke member 16.
Attached to the cable 26, adjacent the second end 30 thereof is a weight stack portion 32. Such weight stack portion 32 of the balanced weight assembly 20 provides a predetermined amount of substantially constant tension to be applied to such catenary system 10.
Now reference is made, more particularly, to Figures 1 through 4 of the drawings. Illustrated therein is one of the presently preferred embodiments of the invention in which such improved cable type brake apparatus, generally designated, 40 is pivotally attached to such pole 18. The cable brake apparatus 40 is disposed on the pole 18 at a point located intermediate that portion of such balanced weight assembly 20 attached to the upper end portion of such pole 18 and the weight stack portion 32. In this embodiment of the invention, the pivotal attachment of the cable brake apparatus 40 to the pole 18 is achieved by at least one and,preferably, by a pair of mounting brackets 34 (upper and lower) attached to such pole 18 and a bolt 36 disposed through both such upper and lower mounting brackets 34 and the housing structure 38 of such emergency cable brake apparatus 40.
In addition to the housing structure 38, such emergency cable brake apparatus 40 further includes a cable gripping means, generally designated 50. Cable gripping means 50 has a first portion 42 thereof immovably secured within and to such housing structure 38 and a second portion 44 thereof pivotably secured within and to the housing structure 38. The second portion 44 of ~1~3368 such cable gripping means 50 being cooperable with such first portion 42 of the cable gripping means 50 for both gripping and holding the cable 26 when such tension on such cable 26 is suddenly removed.
The final essential component of the emergency cable brake 40, according to the present invention, is a trigger means, generally designate 60, having a first portion 46 thereof rotatably secured within such housing structure 38 for sensing any undesirable and sudden acceleration of such cable 26. A second portion 48 of such trigger means 60 is pivotably connected to a predetermined surface 52 of such first portion 46 of the trigger means 60. Such second portion 48 of the trigger means 60 engages a third portion 54 of such trigger means 60 which is pivotably connected to the housing structure 38 and engagable with such cable gripping means 50 for releasing such cable gripping means 50 so that further free fall of such cable 26 is stopped.
According to the presently preferred embodiment of the invention of the improved emergency cable brake apparatus 40, the housing structure 38 includes a pair of slot-like openings 56 and 58 formed therein to enable such cable 26 to pass through such housing structure 38. Additionally, in this embodiment, such housing structure 38 further includes a cover member 62 which is at least one of removable from such housing structure 38 and pivotable away from such housing structure 38 to enable the cable brake apparatus 40 to be installed after such cable 26 has been installed.
The improved emergency cable brake apparatus 40 further includes a guide pulley 64 rotatably secured within and to such housing structure 38 closely adjacent a predetermined one 56 of the pair of slot-like openings 56 and 58 for guiding such cable 26 through the housing structure 38 in a desired path.
The first portion 42 of such cable gripping means 50 includes a groove-like portion 66 disposed closely adjacent a first side of such cable 26 in the presently preferred embodiment and the second portion 44 of such cable gripping means 50 is at least one cam-like member having a predetermined surface 68 engagable with an opposed second side of such cable 26. Preferably, the predetermined surface 68 includes a plurality of knurled surfaces.
In addition, it is also presently preferred that such second portion 44 of such cable gripping means 50 includes a pair of cam-like members 44 and that the cable brake apparatus 40 further includes a means 70 for connecting such at least one cam-like member to a second one of such pair of cam-like members 44.
In the embodiment being described, such first portion 46 of the trigger means 60 is, preferably, a pulley member 46 engaged with one side of such cable 26. The second portion 48 of such trigger means 60 is a plurality of paddle-like members 48 pivotably secured to one surface 52 of such pulley member 46 and the third portion 54 of such trigger means 60 is a release arm 54 having a portion 72 thereof engaged in a slot formed in a portion of such cable gripping means 60.
As discussed above, the function of the Balance Weight Assembly is to apply a constant tension to the contact and messenger wires during changing atmospheric conditions, i.e.
ambient temperature changes. It accomplishes this via a balance weight stack which applies a constant force to the contact and messenger wire. During normal operation, due to contraction and expansion, the counter weight stack moves up and down according to ~113~68 the temperature of the contact and messenger wires. Under cold conditions, it is in the upper position and during hot conditions, the lower position. This assembly allows the tension of the contact and messenger wires to be constant under varying ambient temperatures. The cable brake, during normal operation, allows for the cable to pass through the unit without resistance. The tripping mechanism monitors the acceleration of the cable. When the messenger and/or contact wires fail, the tension load releases and causes the weights to free-fall to the ground. The cable brake is used to prevent the weights from impacting the ground. The cable brake consists of two major components. One, the mechanism that senses the acceleration of the wire rope, and two, the gripping mechanism that stops the cable. Figures two and three show the trigger mechanism, idler pulley, release arm, cams, linkage, wedge block, ice scrapers, and reset handles. All of which is mounted in a housing. Under normal operating conditions, the cable moves up and down through the assembly turning both the tripping pulley and the idler pulley. Excessive ice is removed from the cable via two ice scrapers mounted on the top and bottom.
When a contact and/or messenger wire failure occurs, the acceleration of the cable through the unit is sensed by the trigger mechanism. The trigger mechanism, in conjunction with the release arm, frees the cams and allows them to fall into place and engage the cable. The cam movement and the trigger mechanism is based on gravity, which removes any need for adjustment and also minimizes the chances of product failure over its lifetime.
In operation, the trigger mechanism senses the down acceleration of the cable which cause centrifugal forces to act on a set of paddles attached to the trigger pulley. As the cable ~1 13~68 acceleration increases from zero to 1-G, the paddles overcome gravitational forces and swing outward. The centrifugal energy of the paddles is transferred to the release arm through impacts on the release arm pegs. The release arm pivots out from the cam slot and frees the cams. The cable is gripped by two linked cams that engage the cable after being released by the trigger. The amount of cam-cable engagement, the cam material, and the dimensional profile of the cams lend to the amount of friction generated by the cams. The amount of friction required to stop the weight stack is dependent on the speed in which the mechanism is triggered and the condition of the cable.
Additionally, the present invention has the capability for ice removal provided by the two pulleys. This is due to the slight offset path of the cable routing through the cable brake. The cable brake is self-aligning to the cable due to the size of the idler pulley. The cable brake can be retrofitted into any existing balance weight assembly with minimal effort. And, since the major acting force on the components is gravity, mi n i m~ 1 maintenance effort is required.
It is evident from the above description of the invention that the emergency cable brake prevents the balance weight assembly's counter weights from falling to the ground during a contact or messenger wire failure. This prevents pole foundation damage and minimizes overhead cantenary hardware damage due to the effects of impact loads of the free-falling counter-balance weight. The invention also provides a relatively maintenance-free component which is easy to install and reset once tripped. This allows installation crews, inspection crews and repair crews to minimize their efforts during operation of the cable brake. Further, the - . ~143368 invention will minimize the damage to the pulley cable when the messenger and/or contact wires have failed. ~ini~izing the damage to the cable caused by friction reduces the hazard of this failing during operation. Finally, the invention provides a positive, swift means of sensing the abnormally high acceleration of the weights but ignore normal movement. This allows the cable brake to react to the falling weights quickly, reducing the amount of energy the cable brake must dissipate.
Although a number of presently preferred and various alternative embodiments of the instant invention have been described in detail above in conjunction with the several drawing Figures, it should be noted and understood that various other modifications and adaptations of the improved emergency cable brake type apparatus can be envisioned by those persons who are skilled in this particular art without departing from either the spirit of the invention or the scope of the appended claims.
Claims (22)
1. An improved emergency cable brake type apparatus capable of both seizing and holding a cable when an undesirable event occurs in which tension such cable is being subjected to is suddenly removed, said improved emergency cable brake apparatus comprising:
(a) a housing structure;
(b) a cable gripping means having a first portion thereof immovably secured within and to said housing structure and a second portion thereof pivotably secured within and to said housing structure, said second portion of said cable gripping means being cooperable with said first portion of said cable gripping means for gripping and holding such cable when such tension on such cable is suddenly removed; and (c) a trigger means having a first portion thereof rotatably secured within said housing structure for sensing any undesirable and sudden acceleration of such cable, a second portion of said trigger means is pivotably connected to a predetermined surface of said first portion of said trigger means, said second portion of said trigger means engages a third portion of said trigger means which is pivotably connected to said housing structure and engagable with said cable gripping means for releasing said cable gripping means so that further free fall of such cable is stopped.
(a) a housing structure;
(b) a cable gripping means having a first portion thereof immovably secured within and to said housing structure and a second portion thereof pivotably secured within and to said housing structure, said second portion of said cable gripping means being cooperable with said first portion of said cable gripping means for gripping and holding such cable when such tension on such cable is suddenly removed; and (c) a trigger means having a first portion thereof rotatably secured within said housing structure for sensing any undesirable and sudden acceleration of such cable, a second portion of said trigger means is pivotably connected to a predetermined surface of said first portion of said trigger means, said second portion of said trigger means engages a third portion of said trigger means which is pivotably connected to said housing structure and engagable with said cable gripping means for releasing said cable gripping means so that further free fall of such cable is stopped.
2. An improved emergency cable brake apparatus, according to claim 1, wherein said housing structure includes a pair of slot-like openings formed therein to enable such cable to pass through said housing structure.
3. An improved emergency cable brake apparatus, according to claim 2, wherein said housing structure further includes a cover member which is at least one of removable from said housing structure and pivotable away from said housing structure to enable said cable brake apparatus to be installed after such cable has been installed.
4. An improved emergency cable brake apparatus, according to claim 2, wherein said emergency cable brake apparatus further includes a guide pulley rotatably secured within and to said housing structure closely adjacent a predetermined one of said pair of slot-like openings for guiding such cable through said housing structure in a desired path.
5. An improved emergency cable brake apparatus, according to claim 1, wherein said first portion of said cable gripping means includes a groove-like portion disposed closely adjacent a first side of such cable.
6. An improved emergency cable brake apparatus, according to claim 5, wherein said second portion of said cable gripping means is at least one cam-like member having a predetermined surface engagable with an opposed second side of such cable.
7. An improved cable type brake apparatus, according to claim 6, wherein said predetermined surface includes a plurality of knurled surfaces.
8. An improved emergency cable brake apparatus, according to claim 6, wherein said second portion of said cable gripping means includes a pair of cam-like members and said cable brake apparatus further includes a means for connecting said at least one cam-like member to a second one of said pair of cam-like members.
9. An improved emergency cable brake apparatus, according to claim 1, wherein said first portion of said trigger means is a pulley member engaged with one side of such cable.
10. An improved emergency cable brake apparatus, according to claim 9, wherein said second portion of said trigger means is a plurality of paddle-like members pivotably secured to one surface of said pulley member.
11. An improved cable type brake apparatus, according to claim 10, wherein said third portion of said trigger means is a release arm having a portion thereof engaged in a slot formed in a portion of said cable gripping means.
12. In an overhead suspended catenary system, having both a messenger wire portion and a contact wire portion connected at one end thereof to a yoke-like member and a balanced weight assembly connected to said yoke and a pole member to provide a predetermined amount of substantially constant tension on such messenger wire portion and such contact wire portion of such catenary system, the improvement therewith of a cable type brake apparatus comprising:
(a) a housing structure;
(b) a cable gripping means having a first portion thereof immovably secured within and to said housing structure and a second portion thereof pivotably secured within and to said housing structure, said second portion of said cable gripping means being cooperable with said first portion of said cable gripping means for gripping and holding such cable when such tension on such cable is suddenly removed; and (c) a trigger means having a first portion thereof rotatably secured within said housing structure for sensing any undesirable and sudden acceleration of such cable, a second portion of said trigger means is pivotably connected to a predetermined surface of said first portion of said trigger means, said second portion of said trigger means engages a third portion of said trigger means which is pivotably connected to said housing structure and engagable with said cable gripping means for releasing said cable gripping means so that further free fall of such cable is stopped.
(a) a housing structure;
(b) a cable gripping means having a first portion thereof immovably secured within and to said housing structure and a second portion thereof pivotably secured within and to said housing structure, said second portion of said cable gripping means being cooperable with said first portion of said cable gripping means for gripping and holding such cable when such tension on such cable is suddenly removed; and (c) a trigger means having a first portion thereof rotatably secured within said housing structure for sensing any undesirable and sudden acceleration of such cable, a second portion of said trigger means is pivotably connected to a predetermined surface of said first portion of said trigger means, said second portion of said trigger means engages a third portion of said trigger means which is pivotably connected to said housing structure and engagable with said cable gripping means for releasing said cable gripping means so that further free fall of such cable is stopped.
13. An overhead suspended catenary system having an improved emergency cable brake apparatus, according to claim 12, wherein said housing structure includes a pair of slot-like portions formed through a pair of opposed wall portions thereof to enable such cable to pass through said housing structure.
14. An overhead suspended catenary system having an improved emergency cable brake type apparatus, according to claim 13, wherein said housing structure further includes a cover member which is at least one of removable from said housing structure and pivotable away from said housing structure to enable said cable brake apparatus to be installed after such cable has been installed.
15. An overhead suspended catenary system having an improved emergency cable brake type apparatus, according to claim 13, wherein said emergency cable brake apparatus further includes a guide pulley rotatably secured within and to said housing structure closely adjacent a predetermined one of said pair of slot-like openings for guiding such cable through said housing structure in a desired path.
16. An overhead suspended catenary system having an improved emergency cable brake type apparatus, according to claim 12, wherein said first portion of said cable gripping means includes a groove-like portion disposed closely adjacent a first side of such cable.
17. An overhead suspended catenary system having an improved emergency cable brake apparatus, according to claim 16, wherein said second portion of said cable gripping means is at least one cam-like member having a predetermined surface engagable with an opposed second side of such cable.
18. An overhead suspended catenary system having an improved emergency cable brake type apparatus, according to claim 17, wherein said predetermined surface includes a plurality of knurled surfaces.
19. An overhead suspended catenary system having an improved emergency cable brake type apparatus, according to claim 18, wherein said second portion of said cable gripping means includes a pair of cam-like members and said cable brake apparatus further includes a means for connecting said at least one cam-like member to a second one of said pair of cam-like members.
20. An overhead suspended catenary system having an improved emergency cable brake apparatus, according to claim 12, wherein said first portion of said trigger means is a pulley member engaged with one side of such cable.
21. An overhead suspended catenary system having an improved emergency cable brake type apparatus, according to claim 20, wherein said second portion of said trigger means is a plurality of paddle-like members pivotably secured to one surface of said pulley member.
22. An overhead suspended catenary system having an improved emergency cable brake type apparatus, according to claim 21, wherein said third portion of said trigger means is a release arm having a portion thereof engaged in a slot formed in a portion of said cable gripping means.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US36590494A | 1994-12-29 | 1994-12-29 | |
| US08/365,904 | 1994-12-29 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2143368A1 true CA2143368A1 (en) | 1996-06-30 |
Family
ID=23440861
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2143368 Abandoned CA2143368A1 (en) | 1994-12-29 | 1995-02-24 | Emergency cable brake |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2143368A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105501229A (en) * | 2016-01-29 | 2016-04-20 | 田清澍 | Rope breakage protecting device for steel wire ropes of aerial passenger conveying device |
| WO2023011537A1 (en) * | 2021-08-06 | 2023-02-09 | 广东博智林机器人有限公司 | Suspension system and suspension emergency release method |
-
1995
- 1995-02-24 CA CA 2143368 patent/CA2143368A1/en not_active Abandoned
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105501229A (en) * | 2016-01-29 | 2016-04-20 | 田清澍 | Rope breakage protecting device for steel wire ropes of aerial passenger conveying device |
| CN105501229B (en) * | 2016-01-29 | 2017-09-19 | 田清澍 | A kind of preventing steel wire rope of overhead passenger rope broken protector |
| WO2023011537A1 (en) * | 2021-08-06 | 2023-02-09 | 广东博智林机器人有限公司 | Suspension system and suspension emergency release method |
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