APPARATUS FOR LOCKING DOOR

Technical Field

[1] The present invention relates to a door locking device used to open or close a door disposed in an indoor or outdoor entrance of a building, and more particularly, to a door locking device capable of opening the door by only pushing or pulling a door knob assembly in both directions. Background Art

[2] A door of a building includes a handle used to open and close an entrance thereof.

The handle is connected to a door latch device to fix and release the door to and from a door frame.

[3] Conventionally, when a user wants to open the closed door disposed in the entrance, the user have to perform two operations of turning the handle in one direction and pulling or pushing the door. More specifically, after locked door latchedto the door frame is released by turning the handle of the door, the door is pulled or pushed at a time to be opened, so that a large starting force is needed to open the door due to a force of inertia of the door. Therefore, when the user pulls or pushes the door after turning the handle, the door is abruptly opened, so that the user feels uncomfortable. In addition, a large force is needed to fully open the door, so that a weak user such as a child cannot easily open the door.

[4] In order to solve the aforementioned problems, an invention is disclosed in utility model registration number 0312859 (hereinafter, denoted by a "related invention"). The related invention relates to a door locking device capable of opening a door by pushing or pulling the door disposed in an entrance in one direction.

[5] However, the related invention has problems.

[6] FIG. 1 is a cross-sectional view showing an assembled state of the door locking device according to the related invention.

[7] First, in the related invention, an operation of opening a handle is limited to one direction. More specifically, as a structure shown in FIG. 1, the door is opened only when the handle is pushed in Fl direction. However, there is a problem in that, the structure cannot be employed by a door which is opened in both directions. In addition, sometimes, while the user's body pushes the door, the user applies force to the handle in an opposite direction. In this case, the user may feel comfortable rather than applying force to the door in an opening direction. In this case, the door locking device of the prior invention cannot be operated.

[8] In the relatedinvention, a latch bolt 70 is arranged to be rotated about a hinge joint

72 by a force F2 applied to the latch bolt 70 by a door frame 6. Therefore, the locked door is released to be opened. In this case, when the handle is pushed by a large force, the door is moved forward before the latch bolt 70 is rotated, so that the latch bolt 70 may impact the door frame. Accordingly, there is a problem in that the door is not operated smoothly. Disclosure of Invention Technical Problem

[9] The present invention provides a door locking device capable of opening and closing a door by pushing or pulling a knob and smoothly opening and closing the door. Technical Solution

[10] According to an aspect of the present invention, there is provided a door locking device includes: a door latch device built in a door and provided with a latch protruding from the door latch device and a shaft-engaged portion; a door knob assembly engaged with the door to move toward or backward from the door; a shaft having one end engaged with the shaft-engaged portion and the other end engaged with the door knob assembly; a knob cam device translating a movement of the door knob assembly toward or backward from the door into a rotational motion about the shaft; and a latch cam portion translating a rotational motion of the shaft-engaged portion into a rotational motion of the latch. Accordingly, the door is opened by only pushing or pulling the door knob assembly. In addition, the latch is forcibly rotated by pushing or pulling the knob, so that the door is smoothly opened and closed.

[11] In the above aspect, the door knob assembly may include: a fixed portion fixed to a door; a knob portion engaged with the fixed portion to move linearly with respect to the fixed portion; a fixed cam fixed to the fixed portion; and a rotational cam fixed to the knob portion and engaged with the fixed cam.

[12] In addition, the door knob assembly may further include a shaft having one end engaged with the rotational cam and the other end engaged with a latch device which is built in a door, wherein the fixed cam and the rotational cam may be arranged to translate a linear motion of the knob portion into a rotational motion of the shaft.

[13] According to another aspect of the present invention, there is provided a door latch device including: a latch case provided with a latch hole opening toward a door and a shaft penetrating hole into which a shaft provided to a door knob assembly penetrates; a shaft-engaged portion engaged with the latch case and engaged with the shaft inserted into the penetrating hole to rotate about the shaft; a latch-engaged portion engaged with the latch case to move linearly toward the latch hole; and a latch hinged to the latch-engaged portion to protrude from the latch hole.

Advantageous Effects

[14] According to embodiments of the present invention, various effects are obtained as follows. However, the present invention is implemented not only when all the following effects are shown. [15] First, a door locking device according to the present invention is opened by pushing or pulling a door knob assembly. As a result, a pushing or pulling direction becomes coincident with an opening direction, so that the door can be easily opened. [16] In addition, the present invention can be implemented in a both directions opening/ closing door. In other words, the door is opened by pushing or pulling the door knob assembly. [17] In addition, a latch according to the present invention inclines when the door is opened, so that the door can be smoothly opened. [18] While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the appended claims.

Brief Description of the Drawings

[19] FIG. 1 is a cross-sectional view showing a conventional door locking device;

[20] FIG. 2 is an exploded perspective view showing a door locking device according to an embodiment of the present invention;

[21] FIG. 3 is a perspective view showing a latch device of FIG. 2;

[22] FIG. 4 is a perspective view showing a state of the latch device of FIG. 3 in a state that a portion of a case is removed;

[23] FIG. 5 is an exploded perspective view showing a shaft-engaged portion of FIG. 4;

[24] FIG. 6 is an exploded perspective view showing a locking device of FIG. 4;

[25] FIG. 7 is a perspective view showing a latch-engaged portion of FIG. 4;

[26] FIGS. 8 and 9 are perspective views showing a latch of FIG. 4;

[27] FIG. 10 is a perspective view showing a first linear motional member of FIG. 4;

[28] FIG. 11 is a perspective view showing a second linear motional member of FIG. 4;

[29] FIGS. 12 and 13 are perspective views showing an auxiliary cam member of FIG.

4; [30] FIGS. 14 and 15 are side elevation views showing motions of a second linear motional member, an auxiliary cam member, and a latch according to a motion of the second linear motional member;

[31] FIG. 16 is a perspective view showing a door knob assembly of FIG. 2;

[32] FIG. 17 is a cross-sectional view showing the door knob assembly taken along line

VII-VII of FIG. 16;

[33] FIG. 18 is a perspective view showing a knob portion of FIG. 16;

[34] FIG. 19 is a cross-sectional view showing the knob portion taken along line VII-VII of FIG. 16;

[35] FIG. 20 is a perspective view showing a knob cam device of FIG. 17;

[36] FIGS. 21 and 22 are plan views showing operations of a locking device of FIG. 17;

[37] FIG. 23 is a cross-sectional view showing a door knob assembly in a state the door knob assembly is pulled; and

[38] FIG. 24 is a cross-sectional view showing a door knob assembly in a state that the door knob assembly is pushed. Mode for the Invention

[39] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the attached drawings.

[40] However, in the description, detailed description of well-known functions and structures is omitted in order to clarify the subject matter of the present invention.

[41] FIG. 2 is an exploded perspective view showing a door locking device according to an embodiment of the present invention.

[42] As shown in FIG. 2, the door locking device according to the embodiment ofthe present invention includes a door latch device 1000 which is built in a door 15 and includes a latch, a door knob assembly 2000 engaged with the door 15 to move toward or backward from the door 15, and a shaft 2001 having one end engaged with the door latch device 1000 and the other end engaged with the door knob assembly 2000.

[43] FIG. 3 is a perspective view showing the latch device of FIG. 2, and FIG. 4 is a perspective view showing a state of the latch device of FIG. 3 in a state that a portion of a case is removed.

[44] The latch device 1000 includes a latch case 1100 provided with a latch hole 1131 opened toward the door frame 15 and a shaft penetrating hole 1112 into which the shaft 2001 penetrates, a shaft-engaged portion 1200 engaged with the latch case 1100 to rotate about the shaft 2001 penetrating into the shaft penetrating hole 1112 and engaged with the shaft 2001, a latch-engaged portion 1600 engaged with the latch case 1100 to move linearly toward the latch hole 1131, a latch 1500 hinged to the latch- engaged portion 1600 to protrude from the latch hole 1131, a latch cam portion 1400 translating a rotational motion of the shaft-engaged portion 1200 into a rotational motion of the latch 1500 with respect to the latch-engaged portion 1600, a latch linear restitution spring 1700 pressing the latch-engaged portion 1600 toward the latch hole 1131, a latch rotational restitution spring 1800 turning the latch 1500 in such a direction that the latch protrudes from the latch hole 1131 as much as possible, and a locking device 1300 locking a rotation of the shaft-engaged portion 1600.

[45] The latch case 1100 includes a front casing 1110 and a back casing 1120 engaged with each other to face each other, and a side casing 1130 engaged with the sides of the front casing 1110 and the back casing 1120 and exposed to the side of the door 15.

[46] The front casing 1110 is provided with the aforementioned shaft penetrating hole

1112, a locking hole 1114, and an engaging hole 1113 used to engage the front casing 1110 with the back casing 1120. The back casing 1120 is also provided with a shaft penetrating hole, a locking hole, and an engaging hole corresponding to the shaft penetrating hole 1112, a locking hole 1114, and an engaging hole 1113 of the front casing 1110, respectively.

[47] The side casing 1130 in which the sides of the front and back casings 1110 and

1120 are inserted is provided with the latch hole 1131 from which the latch 1500 protrudes and a fixing hole 1132 used to fix the side casing 1130 to the side of the door 15. The latch hole 1131 is formed in a rectangular shape, and the fixing hole 1132 is formed in a circular shape to be used for screwing.

[48] FIG. 5 is an exploded perspective view showing a shaft-engaged portion of FIG. 4.

[49] The shaft-engaged portion 1200 includes a front shaft-engaged portion 1200a engaging with the door knob assembly 2000 which installed on a front surface of the door and a back shaft-engaged portion 1200b engaging with the door knob assembly which installed on a rear surface of the door.

[50] The front shaft-engaged portion 1200a includes a body 1210a into which the shaft

2001 is inserted and a power transmitting portion 1220a for transmitting a rotational motion of the front shaft-engaged portion 1200a. A cylinder 121 Ia of the body 1210a is provided with a rectangular opening 1212a into which the shaft 2001 is inserted. The power transmitting portion 1220a is provided with a shaft-engaged portion stopper 1223a protruding. A locking notch 1224a is formed outer portion of the shaft-engaged portion stopper 1223a. In addition, the locking notch 1224a is provided with a snag 1225a protruding to limit a movement of a locking member 1320.

[51] The back shaft-engaged portion 1200b includes a body 1210b into which the shaft

2001 is inserted and a power transmitting portion 1220b for transmitting a rotational motion of the back shaft-engaged portion 1200b. A cylinder 121 Ib of the body 1210b is provided with a rectangular opening 1212b into which the shaft 2001 is inserted. The power transmitting portion 1220b is provided with a shaft-engaged portion stopper 1223b protruding. A locking notch 1224b is formed outer portion of the shaft-engaged portion stopper 1223b.

[52] Here, heights of the locking notches 1224a and 1224b of the front and back shaft- engaged portions 1200a and 1200b are different. More specifically, the locking notch 1224b of the back shaft-engaged portion 1200b is formed to be higher than the locking notch 1224a of the front shaft-engaged portion 1200a. Accordingly, as described later,

rotations of the two shaft-engaged portions 1200a and 1200b are locked at the same time by a small amount of movement of the locking member 1320. Detailed description thereof will be described later.

[53] The two shaft-engaged portions 1200a and 1200b are engaged to align the rectangular concaves 1212a and 1212b.

[54] FIG. 6 is an exploded perspective view showing a locking device of FIG. 4.

[55] The locking device 1300 includes the locking member 1320 including locking protrusions 1323 and 1324 locked by the locking notches 1224a and 1224b formed in the aforementioned shaft-engaged portion 1200, and a locking member housing 1310 accommodating the locking member 1320.

[56] The locking member 1320 includes a locking member body 1321 formed in a rectangular bar shape, a pin-engaged portion 1322 protruding from an end portion of the locking member body 1321 in a pipe shape and having a screw thread formed in an inner surface thereof, and locking protrusions 1323 and 1324 protruding from a side of the locking member body 1321. The pin-engaged portion 1322 is engaged with a locking pin (not shown) provided outside the door. The locking protrusions 1323 and 1324 include a front locking protrusion 1324 and a back locking protrusion 1323. The front locking protrusion 1324 protrudes from a side of the back locking protrusion 1323. More specifically, the front and back locking protrusions 1324 and 1323 are formed in a step shape. Due to the step shape, the front locking protrusion 1324 is engaged with the locking notch 1224a formed in the front shaft-engaged portion 1200a, and the back locking protrusion 1323 is engaged with the locking notch 1224b formed in the back shaft-engaged portion 1200b. In addition, a surface of the front locking protrusion 1323 which contacts the locking notch 1224a is formed in a wedge shape. Accordingly, the surface of the front locking protrusion 1323 is closely engaged with the snag 1225a formed in the front locking notch 1224a.

[57] The locking member housing 1310 is provided with a locking member accommodating portion 1312 in the center thereof and is formed in a shape of a rectangular pipe having an opening facing with the shaft-engaged portion 1200. The opening of the locking member housing 1310 is provided with a disengagement- preventing snag 1313 protruding for preventing the locking member 1320 from disengaging, and an opposite side of the opening is provided with a spring supporting portion 1131 concaved in a circular shape. The locking member accommodating portion 1312 is large enough to accommodate the locking member body 1321 such that the locking member body 1321 moves therein.

[58] FIG. 7 is a perspective view showing a latch-engaged portion of FIG. 4.

[59] The latch-engaged portion 1600 includes two plates 1611 and a connecting plate

1612 for connectingthe ends of the plates 1611. The side plates 1611 are provided with

latch hinge inserted holes 1614, auxiliary cam member hinge inserted holes 1615, and guide protrusions 1613 protruding from the side plates 1611 outwardly and extending in a longitudinal direction thereof. The guide protrusions 1613 moves along guide concaves (not shown) formed in the latch cases 1110 and 1120.

[60] FIGS. 8 and 9 are perspective views showing a latch of FIG. 4.

[61] The latch 1500 is provided with a perpendicular surface 1501 facing forward and an inclined surface 1502 facing backward. Both sides of the latch 1500 are provided with engaged surfaces 1505 with which an auxiliary cam member hinge pin 1439 is engaged when rotated by a predetermined angle. The engaged surfaces 1505 are provided with latch hinge shafts 1504 protruding therefrom. A latch cam surface 1503 is formed between the engaged surfaces 1505. A shape of the latch cam surface 1503 will be described later in description of a latch cam portion. The latch 1500 is engaged with the latch-engaged portion 1600 by inserting the latch hinge shafts 1504 into the latch hinge inserted holes 1614 of the latch-engaged portion 1600.

[62] The latch cam portion 1400 includes a linear motional member 1410 and 1420 engaged with the latch case 1100 to move linearly, a linear translating cam portion translating a rotational motion of the shaft-engaged portion 1200 into a linear motion of the linear motional member 1410 and 1420, and a rotational translating cam portion translating the linear motion of the linear motional member 1410 and 1420 into a rotational motion of the latch 1500.

[63] The linear motional member 1410 includes a first linear motional member 1410 which is a U-shaped to enclose the shaft-engaged portion 1200 and the locking device 1300, a second linear motional member 1420 engaged with a connecting plate 1411 (described in FIG. 10) of the first linear motional member 1410 and engaged with an auxiliary cam member 1440 of the rotational translating portion, and an engaging bolt 1430 for engaging the first and second linear motional member 1410 and 1420.

[64] FIG. 10 is a perspective view showing a first linear motional member of FIG. 4.

[65] The first linear motional member 1410 includes two plates 1412 and the connecting plate 1411 forconnecting ends of the plates 1412 facing toward the latch 1500. The side plates are provided with openings 1414 from which the shaft-engaged portion stoppers 1223a and 1223b protrude. End portions of the openings are provided with linear member snags 1415 for stopping the shaft-engaged portion stoppers 1223a and 1223b according to a rotation of the shaft-engaged portion 1200. The connecting plate 1411 is provided with an engaging hole 1413 with which an engaging bolt is engaged 1430.

[66] The second linearmotional member 1420 includes a connecting plate 1421 contacting the connecting plate 1411 of the first linear motional member 1410 and an auxiliary cam engaged plate 1422 protruding from the connecting plate 1421 toward

the latch 1500. A surface of the connecting plate 1421 facing toward the latch 1500 is provided with a spring supporting concave 1424 and an engaging hole 1425 with which the engaging bolt 1430 is engaged. The auxiliary cam engaged plate 1422 is provided with an engaging protrusion inserted concave 1423 in a longitudinal direction thereof.

[67] The engaging bolt 1430 is engaged with the engaging holes 1413 and 1425 of the first and second linear motional members 1410 and 1420.

[68] The linear translating cam portion includes the aforementioned shaft-engaged portion stoppers 1223a and 1223b and the linear member snags 1415 of the first linear motional member 1410.

[69] The rotational translating cam portion includes the auxiliary cam member 1440 and the latch cam surface 1503 formed in the aforementioned latch 1500.

[70] FIGS. 12 and 13 are perspective views showing an auxiliary cam member of FIG. 4.

[71] The auxiliary cam member 1440 is provided with hinge holes 1443 with which the auxiliary cam member hinge pin 1439 is engaged, a linear member engaging protrusion 1442 inserted into the engaging protrusion inserted concave 1423, and an auxiliary cam protrusion 1441 protruding to contact the latch cam surface 1503. The auxiliary cam protrusion 1441 and the latch cam portion 1503, when the auxiliary cam protrusion 1441 rotates about the auxiliary cam member hinge inserted holes 1615, are arranged to allow the latch 1500 to rotate in an opposite direction.

[72] The latch linear restitution spring 1700 includes a first linear restitution spring 1710 having one end disposed on the spring supporting portion 1311 of the locking member housing 1310 and the other end disposed on the connecting plate 1411 of the first linear motional member 1410 and a second linear restitution spring 1720 having one end disposed on the spring supporting concave 1424 of the second linear motional member 1420 and the other end disposed on the connecting plate 1612 of the latch- engaged portion 1600. The first linear restitution spring 1710 applies force of restitution to the linear motional members 1410 and 1420 in a direction from the shaft- engaged portion 1200 to the latch 1500. The second linear restitution spring 1720 applies force of restitution to the latch-engaged portion 1600 in a direction from the second linear motional member 1420 to the latch 1500. Therefore, the two springs 1710 and 1720 press the latch-engaged portion 1600 toward the latch hole 1131.

[73] The latch rotational restitution spring 1800 may be a torsion spring. The auxiliary cam member hinge pin 1439 is engaged by the spring 1800. One end of the spring 1800 is supported by the connecting plate 1612 of the latch-engaged portion 1600, and the other end of the spring 1800 is supported by the auxiliary cam member 1440. Therefore, the spring 1800 applies the force of restitution to the latch 1500 so that the perpendicular surface 1501 of the latch 1500 always faces forward. More specifically,

the spring 1800 applies the force of restitution in such a direction that the auxiliary cam member hinge pin 1439 is engaged with the engaged surface 1505 so that the perpendicular surface 1501 becomes perpendicular. Accordingly, the latch protrudes from the latch hole 1131 as much as possible.

[74] Now, operations of the aforementioned door latch device 100 are described.

[75] When the shaft 2001rotates, the shaft-engaged portion 1200 also rotates. Next, the shaft-engaged portion stoppers 1223a and 1223b rotate to contact linear member snags 1415, so that the first linear motional member 1410 moves in the opposite direction from the latch 1500.

[76] At the same time, the second linear motional member 1420 moves together with the first linear motional member 1410.

[77] FIGS. 14 and 15 are side elevation views showing motions of a second linear motional member, an auxiliary cam member, and a latch according to a motion of the second linear motional member.

[78] When the second linear motional member 1420 moves in a direction of an arrow I, the linear member engaging protrusion 1442 engaged with the engaging protrusion inserted concave 1423 also moves. As a result, the auxiliary cam member 1440 rotates about the auxiliary cam member hinge pin 1439 inserted into the auxiliary cam member hinge inserted holes 1615 in a direction of an arrow π, and the auxiliary cam protrusion 1441 pushes the latch cam surface 1503 to move. Accordingly, the latch 1500 rotates in a direction of an arrow in.

[79] Therefore, a protruding portion of the latch 1500 is shortened, and at the same time, the perpendicular surface 1501 inclines. Accordingly, when the door rotates in a direction of an arrow IV, the door is opened without snagging in the latch hole 1131. In addition, although the latch 1500 does not fully rotate, the perpendicular surface 1501 inclines, so that the latch 1500 is pushed smoothly by the engaged surface of the latch hole 1131 to be accommodated into the latch device.

[80] FIG. 16 is a perspective view showing a door knob assembly of FIG. 2, and FIG. 17 is a cross-sectional view showing the door knob assembly taken along line VII-VII of FIG. 16.

[81] The door knob assembly 2000 includes a fixed portion 2100 fixed to the door 15, a knob portion 2200 engaged with the fixed portion to move linearly, a knob cam device 2300 for translating a linear motion of the knob portion 2200 into a rotational motion about the shaft 2001, a restitution spring 2400 having one end engaged with the fixed portion 2100 and the other end engaged with the knob portion 2200 to return the knob portion 2200 to a neutral position, and a locking device 2500 locking the linear motion of the knob portion 2200.

[82] The fixed portion 2100 fixed to the door 15 is provided with a knob portion path

2110 and a locking notch 2120 formed in an inner surface of the knob portion path 2110.

[83] FIG. 18 is a perspective view showing a knob portion of FIG. 16, and FIG. 19 is a cross-sectional view showing the knob portion taken along line VII-VII of FIG. 16.

[84] The knob portion 2200 includes a knob body portion2210 formed in a cylindrical shape to be inserted into the knob portion path 2110 and move in a longitudinal direction thereof and a knob 2220 formed by enlarging an end portion of the knob body portion 2210 so as to be easily held. The knob body portion2210 is provided with a cam supporting snag 2231 formed in an inner surface of the knob body portion 2210, so that the knob body portion 2210 is partitioned into a knob cam device accommodated portion 2230 and a locking device accommodated portion 2240. The knob body portion 2210 accommodating the knob cam device accommodated portion 2230 is provided with a cam opening 2232. In addition, a locking device opening 2260 is provided to the knob body portion 2210 to align with the locking notch 2120 of the fixed portion 2100 when the knob portion 2200 is in the neutral position. An end portion on the circumference of the knob body portion 2210 facing toward the door is provided with an engaged notch 2233. The engaged notch 2233 is engaged with a rotational cam supporting member 2270.

[85] FIG. 20 is a perspective view showing a knob cam device.

[86] The knob cam device 2300 includes a fixed cam 2310 fixed to the fixed portion

2100 and a rotational cam 2320 fixed to the knob portion 2200 and engaged with the fixed cam 2310.

[87] The fixed cam 2310 includes an engaging portion 2311 provided with an engaging hole used to fix the fixed cam 2310 to the fixed portion 2100 and a cam protrusion 2312 protruding from the engaging portion 2311. A portion of the fixed cam 2310 is accommodated into the cam device enclosing portion 2230 of the knob portion 2200 through the cam opening 2232.

[88] The rotational cam 2320 is formed in a cylindrical shape and is provided with a cam path 2322 concaved on the circumference of a body 2321 thereof. An end portion of the rotational cam 2320 facing toward the door is provided with a shaft-inserted hole 2 323 into which the shaft 2001 is inserted. The cam path 2322 is formed to be engaged with the cam protrusion 2312 such that the cam protrusion 2312moves therein. In addition, the cam path 2322 is formed such a shape that the rotational cam rotates about the shaft 2001 when the rotational cam 2320 moves in a longitudinal direction. The body 2321 is has a size such that both end portions thereof are supported by the cam supporting snag 2231 and the rotational cam supporting member 2270.

[89] The restitution spring 2400 includes a first restitution spring 2410 having one end supported by the cam supporting snag 2231 and the other end supported by the fixed

cam 2310 and a second restitution spring 2420 having one end supported by the rotational cam supporting member 2270 and the other end supported by the fixed cam 2310. When the knob portion 2200 is pushed or pulled, the restitution spring 2400 returns the knob portion 2200 to a neutral position so that elastic forces of the two restitution springs 2410 and 2420 applied to the knob portion 2200 become the same.

[90] The locking device 2500 includes a locking lever 2510 having a portion exposed outside the knobportion 2200, a lever body 2520 having one end engaged with an locking plate 2530 and the other end engaged with the locking lever 2510 to slide, a middle spring 2540 disposed between the locking lever 2510 and the lever body 2520 to absorb shock, and the locking plate 2530 moving linearly by a rotational motion of the lever body 2520 to be engaged or disengaged with the locking notch 2120.

[91] A portion of the locking lever 2510 exposed outward is provided with a holding protrusion 2511 to be easily held andturned, and the locking lever 2510 is provided with an locking hole 2522 concaved to be engaged with the lever body 2520. A cross- section of the locking hole 2522 is formed in a rectangular shape.

[92] The lever body 2520 includes an locking hole inserting portion 2541 which is inserted into the locking hole 2522 and a locking plate engaged portion 2542 formed in adjacent to the locking plate 2530. The locking hole inserting portion 2541 moves in a longitudinal direction of the locking hole 2522, but a rotational motion of the locking hole inserting portion 2541 is limited. More specifically, a cross-section of the locking hole inserting portion 2541 is formed in a rectangular shape similar to the locking hole 2522, so that the locking hole inserting portion 2541 cannot rotate freely. The locking plate engaged portion 2542 includes two protrusions.

[93] As shown in FIG. 21, the locking plate 2530 is formed in a rectangular shape, and the center thereof is provided with a cam hole 2532. The cam hole 2532 is formed in such a shape that the locking plate 2530 moves linearly when the locking plate engaged portion 2542 rotates.

[94] As described above, when the locking lever 2510 rotates, the lever body 2520 engaged with the locking lever 2510 also rotates, and the locking plate engaged portion 2542 included in the lever body 2520 also rotates, so that the locking plate 2530 passes through the locking device opening 2260 to be engaged with the locking notch 2120. Therefore, the knob portion 2200 is prevented from moving relatively to the fixed portion 2100, so that the door locking device can perform a locking operation.

[95] In addition, when a user pushes the door knob assembly 2000, the locking lever

2510 smoothly moves into the knob portion 2200 due to the middle spring 2540, so that the locking lever 2510 does not press a palm of a hand of the user, and the user does not feel a pain.

[96] FIG. 23 is a cross-sectional view showing the door knob assembly in a state the

door knob assembly is pulled.

[97] As shown in FIG. 23, when the knob portion 2200 is pulled, since the one end of the rotational cam 2320 is supported by the rotational cam supporting member 2270, the rotational cam 2320 moves together with the knob portion 2200. On the contrary, the fixed cam 2310 does not move. Therefore, the cam protrusion 2312 moves along the cam path 2322. Accordingly, the rotational cam 2320 rotates, and the shaft 2001 engaged with the rotational cam 2320 also rotates. In addition, the shaft 2001 is engaged with the shaft-engaged portion 1200 of the latch device, a rotation of the shaft 2001 causes the rotational motion of the shaft-engaged portion 1200.

[98] FIG. 24 is a cross-sectional view showing a door knob assembly in a state that the door knob assembly is pushed.

[99] As shown in FIG. 24, whenthe knob portion 2200 is pushed, since the one end of the rotational cam 2320 is supported by the rotational cam supporting member 2270, the rotational cam 2320 moves together with the knob portion 2200. On the contrary, the fixed cam 2310 does not move.Therefore, the cam protrusion 2312 moves along the cam path 2322. Accordingly, the rotational cam 2320 rotates, and the shaft 2001 engaged with the rotational cam 2320 also rotates. In addition, the shaft 2001 is engaged with the shaft-engaged portion 1200 of the latch device, a rotation of the shaft 2001 causes the rotational motion of the shaft-engaged portion 1200.