ELEVATOR ROPE BRAKING SYSTEM

Abstract: An elevator rope braking system is provided, in which an elevator hauling rope is temporarily supported and locked by the operating plate equipped with a brake lining and which operates by a hydraulic pressure, when the elevator slowly moves due to slippage of the rope or operates at a speed higher than the normal speed, so as to thereby prevent the elevator from slippage or over-speed and achieve a safe operation of the elevator. The elevator rope braking system is installed at the rope side where the elevator is installed or the rope side where the balancing weight is installed, from among ropes caught at the lifting pulley arranged in a machinery room having a winch mounted therein. The elevator rope braking system includes a hydraulic pressure generating unit having a directional solenoid valve and a pressure accumulator which operate in accordance with a signal output from a controller of an elevator; a driving unit having a hydraulic cylinder which receives a driving force from the hydraulic pressure generating unit, an elastic spring and a connection member; and a locking unit having a fixed plate both ends of which are fixed to a housing, and an operating plate which advances or retreats against elastic force of a plurality of springs.

Description: ELEVATOR ROPE BRAKING SYSTEM FIELD OF THE INVENTION The present invention relates to an elevator rope braking system, in which an elevator hauling rope is temporarily supported and locked by the operating plate equipped with a brake lining and which operates by a hydraulic pressure, when the elevator slowly moves due to slippage of the rope or operates at a speed higher than the normal speed, so as to thereby prevent the elevator from slippage or over-speed and achieve a safe operation of the elevator. BACKGROUND OF THE INVENTION In general, elevators are connected to a rope which is hauled up/down by the driving force of a motor, so as to lower or elevate passengers or loads throughout a building. Such an elevating or lowering operation of the elevator is carried out by a guide shoe which is guided by the guide rail at both sides of the elevator. Elevators are equipped with safety devices such as a braking device or lifting motor so as to achieve an in-advance prevention against slippage or over-speed of elevator which is caused due to the deterioration of frictional force between the hauling rope and lifting pulley or weight difference between an elevator car and balancing weight. Conventional emergency braking devices adopt a system in which an abnormal operation of the elevator is controlled by limiting the guide rail for guiding the elevator through a wedging jaw. Such an emergency braking device is constructed in that a governor switch cuts off power being supplied to the motor upon detection of over-speed of elevator, and the wedging emergency braking device for limiting the governor rope limits operation of the guide rail, to thereby stop the operation of elevator. The conventional braking device has drawbacks in that the braking device operates only when the elevator is rapidly hauled down at a speed higher than the normal predetermined speed, and an effective brake mechanism may not be obtained when the elevator slowly slips from the position of operational stoppage or when the elevator is rapidly hauled up at a speed higher than the normal predetermined speed. To overcome such drawbacks, an emergency braking system is proposed in that emergency braking operation for elevator is performed in such a manner that a cylinder rod is maintained at locked state by a solenoid, the locked state of the cylinder rod is released by the solenoid upon detection of the signal indicative of an abnormal operation of the elevator, and the released cylinder rod pulls a brake shoe by the repulsive force of the spring so as to allow the brake shoe to surface- contact the rope. However, such an emergency braking system is economically disadvantageous since the manufacturing cost is high and volume of the braking system increases in order to maintain braking pressure of approximately 1000kg or higher. Korean Patent Laid-open No. 1999-52147 discloses an elevator rope braking device which includes, as shown in Fig. 1, a hydraulic pressure generating unit for receiving signals from a control unit of an elevator and supplying braking force; a repulsive force generating unit consisting of a hydraulic cylinder 125 mounted to a support plate 123 and a connection member 127 having at an outer periphery thereof a spring; a fixed plate 133 having both ends fixed to a housing, and which contacts the connection member 127; and an operating plate 135 installed at an end of the connection member 127 in such a manner that the operating plate 135 advances to or retreats from the fixed plate against the elastic force from the spring. The elevator rope braking device shown in Fig. 1 locks or releases an elevator rope 103 in accordance with the operation of the repulsive force generating unit. However, the elevator rope braking device disclosed in Korean Patent Laid-open No. 1999-52147 is constructed to brake the elevator rope through the movement of the operating plate 135, which causes brake load to be concentrated to the fixed plate 133. Thus, the fixed plate 133 may not sufficiently support such a concentrated overload. Furthermore, a problem still exists in the time consumed from the starting of operation of the operating plate 135 which operates to brake the elevator rope, to the completion of braking operation. SUMMARY OF THE INVENTION The present invention provides a new and improved elevator rope braking system which overcomes the drawbacks enumerated above with respect to the previously patented devices. It is an object of the prevention invention to provide an elevator rope braking system, in which housing and fixed plate have improved structures to correspond to the temporary large load generated upon braking of abnormal motion of elevator rope. It is another object of the present invention to provide an elevator rope braking system which is capable of braking abnormal motion of the elevator rope in a rapid manner. It is still another object of the present invention to provide an elevator rope braking system which is capable of braking elevator even during power failure. To accomplish the above objects of the present invention, there is provided an elevator rope braking system including a hydraulic pressure generating unit having a directional solenoid valve and a pressure accumulator which operate in accordance with a signal output from a controller of an elevator; a driving unit having a hydraulic cylinder which receives a driving force from the hydraulic pressure generating unit, an elastic spring and a connection member; and a locking unit having a fixed plate both ends of which are fixed to a housing, and an operating plate which advances or retreats against elastic force of a plurality of springs. The elevator rope braking system of the prevent invention is constructed to brake the rope side where an elevator is installed or the rope side where a balancing weight is installed, from among the ropes caught at a lifting pulley disposed in the machinery room having - a winch installed therein. DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view illustrating a conventional elevator rope braking system; Figs. 2a and 2b are schematic views illustrating an installed state of an elevator ' rope braking system according to the present invention; Fig. 3 is a perspective view illustrating an elevator rope braking system according to the present invention; Figs. 4a and 4b are plane views illustrating operation of the elevator rope braking system according to the present invention, wherein Fig. 4a illustrates a state where the rope locking is released and Fig. 4b illustrates a state where the rope is locked; Figs. 5a and 5b are perspective views illustrating linings attached, respectively, to a fixed plate and an operating plate of the elevator rope braking system according to the prevent invention; and Fig. 6 illustrates a hydraulic circuit for operating the operating plate in the elevator rope braking system according to the present invention. DETAILED DESCRIPTION OF THE PRESENT INVENTION An elevator rope braking system of the present invention will be explained in more detail with reference to the attached drawings. As shown in Figs. 2a, 2b, 3 and 4a, an elevator rope braking system(A) according to an embodiment of the present invention includes a hydraulic pressure generating unit having a directional solenoid valve and a pressure accumulator which operate in accordance with a signal output from a controller of an elevator; a driving unit 21 having a hydraulic cylinder 25 which receives a driving force from the hydraulic pressure generating unit, an elastic spring 29 and a connection member 27; and a locking unit 31 having a fixed plate 33 both ends of which are fixed to a housing 11, and an operating plate 35 which advances or retreats against elastic force of a plurality of springs. The elevator rope braking system of the prevent invention is constructed to brake the rope side where an elevator is installed or the rope side where a balancing weight is installed, from among the ropes caught at a lifting pulley disposed in the machinery room having a winch installed therein. Referring to Figs. 3 and 4a, the housing 11 is constituted by two sections which are spaced apart from each other in a symmetric manner and have protruded portions 1 1a which have both ends bent inwardly and rectangularly. The driving unit 21 includes the hydraulic cylinder 25 which is provided with a hydraulic pressure through a hydraulic pipe 25b from a hydraulic pressure generating unit 41 penetrating through a support plate 23 fixed inside of the protruded portion of the housing, and the elastic spring 29. The fixed plate 33 and the operating plate 35 contacting a plunger 25a of the hydraulic cylinder 25 have linings 33a and 35a with locking grooves 33b and 35b formed along the surfaces of the fixed plate 33 and the operating plate 35 facing each other, respectively, in such a manner as to tightly support an elevator rope 3. The fixed plate 33 positioned outside of the protruded portion 11a of the housing, and the operating plate 35 and the support plate 23 which are positioned inside between both protruded portions 11a of the housing are supported, together with protruded portions 11a, by connection members 27 which penetrate through the fixed plate 33, the operating plate 34 and the support plate 23 in sequence. The connection member 27 disposed between the fixed plate 33 and the operating plate 35 is equipped with the elastic spring 29. Referring to Fig. 6, the hydraulic pressure generating unit 41 of the elevator rope braking system(A) of the present invention includes a pump 42 for compressing the working fluid contained in a tank 43; an accumulator 44 for storing the working fluid which is pressed at a predetermined pressure by the pump and supplied through a check valve 46; a directional solenoid valve 45 which opens/shuts off in accordance with the elevator operation or stoppage signal so as to change the flow direction of the working fluid; a relief valve 47 for controlling operation of the pump 42; and a pressure switch 48 and a pressure gauge 49. Referring to Figs. 3 and 4a, the driving unit 21 for receiving the working fluid through the hydraulic pipe 25b from the hydraulic pressure generating unit 41, includes the hydraulic cylinder 25 connected to an end of the hydraulic pipe 25b; the support plate 23 through which the hydraulic cylinder 25 penetrates; and the connection member 27 having along the outer periphery thereof the elastic spring 29, and which penetrates through and supports the fixed plate 33, the protruded portion 11a of the housing, the operating plate 35 and the support plate 23. Referring to Figs. 4a, 5a and 5b, the locking unit 31 includes the fixed plate 33 which is fixed outside of one protruded portion 1 1a of the housing through the connection member 27; and the operating plate 35 which is fixed by the connection member 27 between two protruded portions 11a of the housing, and has one surface contacting the front end of the plunger 25a of the hydraulic cylinder 25. The operating plate 35 is pushed by the plunger 25a through the operation of the hydraulic cylinder 25 and pressed toward the fixed plate 33 against the elastic force of the elastic spring 29 arranged along the outer periphery of the connection member 27 between the fixed plate 33 and the operating plate 35. As shown in Figs. 4a and 5a, the fixed plate 33 is equipped with, at the front surface thereof, the lining 33a which has a plurality of locking grooves 33b contacting the elevator rope 3. Referring to Figs. 4a and 5b, the operating plate 35 is equipped with the lining 35a which has a plurality of locking grooves 35b. Count of the connection member 27 having along the outer periphery thereof the elastic spring 29 can be increased or decreased. That is, number of connection members 27 for supporting the support plate 23 and the fixed plate 33 installed to the both sides from the operating plate 35 is not specifically limited. Now, operation of the elevator rope braking system of the present invention will be explained with reference to Figs. 4a and 4b. When an elevator 1 stops its operation at the state where the elevator rope 3 is not supported, as shown in Fig. 4a, the hydraulic cylinder 25 operates by the operation of the hydraulic pressure generating unit 41, thus allowing the plunger 25a arranged at the front end of the hydraulic cylinder 25 to push the operating plate 35, as shown in Fig. 4b. As a consequence, the operating plate 35 slides along with the connection member 27, gets away from the support plate 23 and tightly contacts the fixed plate 33 against the elastic force of the elastic spring 29 interposed between the fixed plate 33 and the operating plate 35. Plural ropes 3 arranged between the operating plate 35 and the fixed plate 33 can be maintained at the locked state by linings 33a and 35a. That is, ropes 3 are tightly supported by locking grooves 33b and 35b formed at linings 33a and 35a, respectively, and maintained at the stopped state. When the elevator 1 is hauled up/down by a button operation at the above-described state, working fluid fed to the hydraulic cylinder 25 by the hydraulic pressure generating unit 41 is re-introduced into the working fluid tank in accordance with the signal of the elevator 1. Subsequently, the plunger 25a pushing the operating plate 35 is retracted into the hydraulic cylinder 25, and at the same time the operating plate 35 gets away from the fixed plate 33 by the elastic force of the elastic spring 29 which is maintained at a compressed state between the operating plate 35 and the fixed plate 33, thus allowing the elevator rope 3 maintained at the locked state by linings 33a and 35a to be released from the locked state, as shown in Fig. 4a. Since the released state of the elevator rope 3 can be maintained until the hydraulic cylinder 25 operates and the operating plate 35 moves toward the fixed plate 33 against the elastic force of the elastic spring 29, the elevator 1 can be hauled up and down by rope. Reference numeral 13 of Figs. 4a and 4b denotes a device for attaching and installing the housing 11 of the elevator rope braking system(A). When the elevator 1 operating in the normal manner at the state where the fixed plate 33 and the operating plate 35 of the locking unit 31 are spaced apart from each other, slips during loading or unloading of passengers, or is rapidly lowered or elevated due to the deterioration of the braking force of the elevator rope braking system, deterioration of the frictional force between the hauling rope and lifting pulley, or the weight difference between the elevator car and balancing weight, the control unit of the elevator transmits a signal to the hydraulic pressure generating unit 41. As described above, the plunger 25a of the hydraulic cylinder 25 is pressed by the operation of the hydraulic pressure generating unit 41, and pushes the operating plate 35. Thus, the operating plate 35 moves toward the fixed plate 33, allowing the rope 3 to be re-locked so as to stop the operation of the elevator 1 in a safe manner. The operating plate 35 of the locking unit 31 has at the surface thereof opposite to the surface contacting the plunger 25a of the hydraulic cylinder 25, the lining 35a having a plurality of locking grooves 35b contacting the elevator rope 3. The fixed plate 33 of the locking unit 31 has at the front surface thereof the lining 33a having a plurality of locking grooves 33b with trapezoidal cross section and which is attached to the fixed plate 33 in a lengthwise direction. Thus, the rope 3 fixed between locking grooves 33b and 35b of linings 33a and 35a can be maintained at a reliably locked state due to a wedge effect. The hydraulic pressure generating unit 41 for operating the driving unit 21 operates as follows. Referring to Fig. 6, when the elevator 1 in operation stops, a need arises to operate the hydraulic cylinder 25 and push, by temporary and large power, the plunger 25a arranged at the front end of the hydraulic cylinder 25 so as to tightly support the elevator rope 3. The working fluid is pressed by the operation of the pump 42, delivered to the accumulator 44 through the check valve 46, and standing by in the accumulator, by being maintained at a predetermined pressure which is set by the pressure switch 48. The working fluid standing by at a predetermined pressure, passes through the directional solenoid valve 45 with the opening of the directional solenoid valve 45 which shuts off the working fluid flow toward the hydraulic cylinder 25, and enters the hydraulic cylinder 25. Thus-introduced working fluid strongly exerts a pushing force to the operating plate 35, and moves the operating plate toward the fixed plate 33, to thereby tightly support the elevator rope 3. At the same time, the working fluid contained at a predetermined pressure in the accumulator 44 flows out toward the hydraulic cylinder 25 at a time. As a consequence, the pressure of the accumulator 44 is lowered, and the pressure switch 48 operates the pump 42 until the accumulator is filled with a predetermined pressure. The working fluid delivered to the accumulator 44 by the pump 42, is maintained at an accumulated state, so as to standby for the subsequent operation of the hydraulic cylinder 25. The working fluid is delivered from the accumulator 44 to the hydraulic cylinder 25 so as to permit the plunger 25a of the hydraulic cylinder 25 to push the operating plate 33. The return line for the directional solenoid valve 45 is open when a power is applied to the directional solenoid valve 45 by an elevator operation re-start signal. Thus, the operating plate 35 pushed toward the fixed plate 33 is returned by the elastic force of the elastic spring 29, and pushed toward the support plate 23, to thereby press the plunger 25a to retract into the hydraulic cylinder 25. The working fluid returns to the tank 43 through the return line of the directional solenoid valve 45. The elevator rope braking system is capable of performing brake operation even during power failure, since the accumulator 44 maintains hydraulic pressure of a predetermined level. In other words, the working fluid is delivered to the hydraulic cylinder 25 when the directional solenoid valve 45 opens in the hydraulic cylinder direction due to the power failure, at the state where the accumulator 44 maintains a predetermined level of hydraulic pressure. As a consequence, the plunger 25a is pushed and presses the operating plate, to thereby brake the elevator rope 3. As described above, an elevator rope braking system of the present invention is advantageous in that structures of the housing and the fixed plate are improved so as to sufficiently correspond to the temporary large load occurred during braking operation for the abnormal motion of the elevator rope, to thereby increase reliability of the system. Furthermore, an elevator rope braking system of the present invention is advantageous in that the operating plate is directly pressed by the plunger of the hydraulic cylinder, to thereby brake abnormal motion of the elevator rope and elevator in a rapid manner. In addition, an elevator rope braking system of the present invention employs an accumulator so as to carry out elevator brake operation even during power failure. While preferred embodiments of the invention have been illustrated and described, it should be understood that the invention is not limited to the specifics of these embodiments, but rather is defined by the appended claims.

Claims: WHAT IS CLAIMED IS: 1. An elevator rope braking system comprising a hydraulic pressure generating unit having a directional solenoid valve and a pressure accumulator which operate in accordance with a signal output from a controller of an elevator; a driving unit having a hydraulic cylinder which receives a driving force from said hydraulic pressure generating unit, an elastic spring and a connection member; and a locking unit having a fixed plate both ends of which are fixed to a housing, and an operating plate which advances or retreats against elastic force of a plurality of springs, characterized in that said elevator rope braking system being constructed to brake a rope side where an elevator is installed or a rope side where a balancing weight is installed, from among ropes caught at a lifting pulley disposed in a machinery room having a winch installed therein, said housing being constituted by two sections which are spaced apart from each other in a symmetric manner and have protruded portions which have- both ends bent inwardly and rectangularly, said driving unit including said hydraulic cylinder which is provided with a hydraulic pressure through a hydraulic pipe from said hydraulic pressure generating unit penetrating through a support plate fixed inside of said protruded portion of said housing, and said elastic spring, said fixed plate and said operating plate contacting a plunger of said hydraulic cylinder having linings with locking grooves formed along surfaces of said fixed plate and said operating plate facing each other, respectively, in such a manner as to tightly support an elevator rope, said fixed plate being positioned outside of said protruded portion of said housing, and said operating plate and said support plate positioned inside between both protruded portions of said housing being supported, together with protruded portions, by connection members which penetrate through said fixed plate, said operating plate and said support plate in sequence, said connection member disposed between said fixed plate and said operating plate being equipped with said elastic spring. 2. ' An elevator rope braking system according to Claim 1, wherein said hydraulic pressure generating unit comprises a pump for compressing a working fluid contained in a tank; an accumulator for storing said working fluid which is pressed at a predetermined pressure by said pump and supplied through a check valve; a directional solenoid valve which opens/shuts off in accordance with an elevator operation or stoppage signal so as to change flow direction of said working fluid; a relief valve for controlling operation of said pump; and a pressure switch and a pressure gauge.

Inventors: PYEON JUN-KI, PYEON, JUN-KI
Applicants: KISAN INFORMATION SYSTEM CO LT, PYEON JUN KI, KISAN INFORMATION SYSTEM CO., LTD., PYEON, JUN-KI
Application year: 2001
Main classification: B66B1
IPC codes: B66B5, B66B15, B66D5