Background Art A door, which is moved to open and close the entrance of a building, has a handle connected to a door lock device adapted to fix the door to a doorframe and release the door from the doorframe.

Generally, conventional handles are of a spherical or straight shape in such a manner as to be easily taken and turned by a user's hand.

The shape of door handle is limited to two types only, thereby making it difficult to obtain a variety of door shapes.

In addition, if a door is to be opened at a state where the door has been closed, two operations of turning the door handle to any one direction with a user's hand and then of pulling or pushing the door should be continuously carried out.

That is, after the handle is first turned to release the locking state of the door to the doorframe, the door is pulled or pushed to be opened, which needs a lot of initial forces at the moment the door is opened. This occurs since the door has an inertia force to remain at its stopped state. Thus, when the handle is turned and the door is then pushed or pulled, the door is suddenly opened, which does give the user a little unnatural feelings.

Thus, in the case where children or the weak people try to open the door with the conventional handle, they should turn the handle, while giving a great force to the handle, but actually, the door is not opened well.

Disclosure of Invention Accordingly, the present invention has been made to solve the above- described problems, and it is an object of the present invention to provide a door lock device that is easily manufactured with a relatively small number of parts, exhibits a substantially low percentage of trouble, does not need the operation of turning a handle such that the handle can be designed in a variety of shapes, in addition to conventional spherical or straight ones, and opens a door just through the application of a relatively slight force of pushing or pulling the handle, which enables children or the weak people to open the door in convenient and smooth ways.

To accomplish the above object, according to the present invention, there is provided a door lock device comprising : a housing having a closed face with a hole formed thereon at one side thereof, an opened face formed at the other side thereof, and hinge grooves extended horizontally along a longitudinal direction on the outer peripheral surface thereof in such a manner as to be perpendicular to the closed face and the opened face; a latch bolt assembly having a pair of hinge shafts that are adapted to be fitted into the hinge grooves, a cut hole cut off vertically with respect to axes of the hinge shafts, a pressurizing face formed inside of the cut hole, and a generally arc face formed having each of the hinge shafts as the central point of a radius thereof; an operation rod assembly having an operation piece formed at one end thereof, the operation piece being adapted to be fitted into the cut hole of the latch bolt assembly in such a manner as to be in contact with the pressurizing face and to be

retracted from a doorframe as the latch bolt assembly is rotated, and a rod formed at the other end thereof to pass through the hole of the closed face, the rod being extended longitudinally from the operation piece; an operation lever adapted to be fitted into the end of the rod; and a spring adapted to be compressed and inserted into the rodof the operation rod assembly in such a manner as to be supported by the operation piece at one end thereof and supported by the closed face at the other end thereof.

Preferably, the operation lever is rotatably coupled by means of a hinge at one end thereof.

The rod of the operation rod assembly preferably has a locking concave groove formed at a bottom surface thereof, and wherein the door dock device further comprises a stopper that is disposed below the locking concave groove to be deviated therefrom by a resilient force of the spring and a manipulating shaft that is connected to a door lock on a door side for raising the stopper such that the stopper is fitted into the locking concave groove.

Preferably, the pressurizing face of the latch bolt assembly is curved at a predetermined inclination angle in such a manner as to smoothly push the operation rod assembly to a door side as the latch bolt assembly is rotated.

Also preferably, the operation piece of the operation rod assembly is provided with a guiding inclined face that has a partially protruded inclination with respect to the arc faces of the latch bolt assembly and guides a smooth retracting movement of the latch bolt assembly when a door starts to be closed by initially contacting the doorframe.

In addition, the operation lever is preferably provided with a plate spring that is adapted to move an operation point at which a force from a first or second handle is

applied.

Brief Description of the Drawings Further objects and advantages of the invention can be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. 1 is a perspective view of the assembled state of a door lock device according to the present invention; FIG. 2 is a view of the parts of the door lock device of the present invention; FIG. 3 is an exploded perspective view of the door lock device of the present invention; FIG. 4 is a sectional view of the door lock device while a door is closed ; FIG. 5 is a sectional view of the door lock device while a door is opened; FIG. 6 is a view of the operation state of the door lock device while a door is closed; FIG. 7 is a view of the operation state of the door lock device while a door is opened ; FIG. 8 is a sectional view taken along the line A--A in FIG. 4; and FIGS. 9 and 10 are views of the operation states of an auxiliary lock assembly of the door lock device of the present invention.

Best mode for Carrying Out the Invention Now, an explanation of the preferred embodiment of the present invention will be in detail given with reference to attached drawings.

FIG. 1 is a perspective view of the assembled state of a door lock device

according to the present invention. As shown, the door lock device of the present invention includes a handle shaft 11 that conducts a linear movement. The handle shaft 11 has a first handle 12 at one side thereof and a second handle 14 at the other side thereof.

The first and second handles 12 and 14 are in a shape of an'A', as shown in FIG. 1, and may be in different shapes, like a ball, a donut, and so on.

The handle shaft 11 is provided with a handle shaft support 40 that is formed around the outer peripheral surface thereof, the handle shaft support 40 having an opening through which the handle shaft 11 is passed in a manner of being fitted thereinto such that the handle shaft support 40 serves to guide and support the handle shaft 11. The handle shaft support 40 has a hole formed on a side perpendicular to the side on which the opening through which the handle shaft 11 is fitted is formed, the hole being adapted to guide and support a housing 50 in which the parts of the door lock device of the present invention are housed. The housing 50 has a latch bolt assembly 70 formed at the other end opposite to one end supported by the handle shaft support 40 in such a manner as to be protruded therefrom and inserted thereinto. The latch bolt assembly 70 has an operation rod assembly 80 disposed in the middle portion thereof in such a manner as to be inserted and guided thereinto.

In this manner, if a door is in a closed position, the latch bolt assembly 70 and a part of the operation rod assembly 80 are inserted into a doorframe 20.

The door lock device of the present invention has a manipulating shaft 106 formed at one side of the handle shaft support 40, the manipulating shaft 106 being connected with an outside key device 108 for conducting auxiliary door locking.

FIG. 2 is a view of the parts of the door lock device of the present invention, and FIG. 3 is an exploded perspective view of the door lock device of the present

invention. According to the present invention, when the parts shown in FIG. 3 are assembled, such the assembling result as shown in FIG. 2 is shown.

As shown in FIGS. 2 and 3, the housing 50 of the door lock device according to the present invention has a generally cylindrical shape that is elongated in a longitudinal direction, for receiving the operation rod assembly 80. The housing 50 includes a closed face 56 with a hole 52 formed thereon at one side thereof and an opened face 58 formed at the other side thereof. The housing 50 further includes hinge grooves 54 each extended horizontally along a longitudinal direction on the outer peripheral surface thereof in such a manner as to be perpendicular to the closed face 56 and the opened face 58, with a result that a pair of hinge shafts 73 of the latch bolt assembly 70 are coupled to the hinge grooves 54 of the housing 50.

As shown in FIG. 3, the operation rod assembly 80 has the rod 84 extended longitudinally therefrom, serving to apply a predetermined force. The rod 84 has an operation piece 82 protruded to form a gently curved face along a longitudinal direction at one side thereof to pass through the hole 52 of the closed face 56 and a locking portion 86 protruded in a lateral direction at the other side thereof. In this case, the rod 84 is formed of the shaft having the same thickness, and may be also formed of a plurality of shafts having different thicknesses from one another.

The operation piece 82 includes a curved portion 82b and a guiding inclined face 82a that are formed, having different inclination angles from each other.

As shown in FIG. 3, the latch bolt assembly 70 of the door lock device of the present invention is of a generally fan shape, including the pair of hinge shafts 72 disposed on the coaxial line in such a manner as to be fitted into the hinge grooves 54, a cut hole 74 cut off vertically with respect to the hinge shafts 72, a pressurizing face 76 formed inside of the cut hole 74, and a generally arc face 78 formed having each of

the hinge shafts 72 as the central point of a radius thereof.

The pressurizing face 76 of the latch bolt assembly 70 is curved at a predetermined inclination angle in such a manner as to smoothly push the operation rod assembly 80 to a door side as the latch bolt assembly 70 is rotated with respect to the hinge shafts 72.

The hinge grooves 54 into which the hinge shafts 72 of the latch bolt assembly 70 coming out of and into the housing 50 are rotatably mounted are formed longitudinally along a longitudinal direction of the housing 50, hence enabling the latch bolt assembly 70 to carry out a linear motion and simultaneously a rotating motion.

The operation rod assembly 80 is provided with a force delivering assembly 60 that is formed at the other end thereof opposite to the one end to which the latch bolt assembly 70 is attached. The force delivering assembly 60 includes an operation lever 64 that serves to delivery the force applied from the outside to the operation rod assembly 80.

The operation lever 64 has three protruding portions. First, at the first protruding portion the operation lever 64 has an operation lever protruding portion 61 adapted to be locked to the locking portion 86 of the operation rod assembly 80. The operation lever protruding portion 61 is formed in such a manner that the rod 84 of the operation rod assembly 80 is fitted thereinto, and is then supported by the locking portion 86 of the operation rod assembly 80.

At the second protruding portion the operation lever 64 has a hinge 63 relative to which the operation lever 64 is rotated. The hinge 63 is assembled with a door lock body such that the operation lever 64 is rotated with respect to the hinge 63.

At the third protruding portion the operation lever 64 has a plate spring 65

adapted to deliver a force applied from the outside with respect to the hinge 63 of the operation lever 64. In this manner, the plate spring 65 is bonded to the operation lever 64 in a welding manner, not moving with respect to the operation lever 64.

Now, an explanation on the assembled relation among the parts of the door lock device of the present invention will be given in detail.

The operation rod assembly 80 is in engagement with the operation lever 64 that is rotated with respect to the hinge 63 by the force applied to the first handle 12 or the second handle 14 such that it is moved to a direction distance from the doorframe, hence allowing the latch bolt assembly 70 to be rotated to release the locking state of the door. After that, the operation rod assembly 80 pushes the latch bolt assembly 70 again by an elastically repulsive force of a spring 62, hence allowing the latch bolt assembly 70 to return to the locking state.

The operation rod assembly 80 has the operation piece 82 formed at one end thereof, the operation piece 82 being adapted to be fitted to the cut hole 74 of the latch bolt assembly 70 in such a manner as to be in contact with the pressurizing face 76 and to be retracted from the doorframe as the latch bolt assembly 70 is rotated, and the rod 84 formed at the other end thereof, the rod 84 being extended longitudinally from the operation piece 82 and having the locking portion 86 supportably connected on the operation lever 64.

The operation piece 82 of the operation rod assembly 80 is provided with the guiding inclined face 82a that is partially protruded against the arc faces of the latch bolt assembly 70 and guides a gentle movement of the latch bolt assembly to the doorframe when the door starts to be closed by initially contacting the doorframe.

A spring 90 is adapted to be compressed and fitted around the rod 84 of the operation rod assembly 80, serving to push the operation rod assembly 80 toward the

latch bolt assembly 70. The spring 90 is adapted to be supported by the operation piece 82 at one end thereof and supported by the closed face 56 of the housing 50 at the other end thereof.

On the other hand, in the case where a key is inserted into a door lock (not shown) to the door side, the door lock device according to the present invention includes an auxiliary lock assembly 100 that controls the operation of the operation rod assembly 80 to thereby carry out safety locking.

The auxiliary lock assembly 100 is adapted to be fitted into a locking concave groove 84a on the rod 84 of the operation rod assembly 80, and includes a stopper 104 adapted to be deviated from the locking concave groove 84a at an initial state thereof and a manipulating shaft 106 adapted to be connected to the door lock on the door side to raise the stopper 104 such that the stopper 104 is fitted into the locking concave groove 84a.

Under the above construction, an explanation of the operation of the door lock device of the present invention will be given.

FIG. 4 is a sectional view of the door lock device while a door is closed, and FIG. 5 is a sectional view of the door lock device while a door is opened. FIG. 6 is a view of the operation state of the door lock device while a door is closed, and FIG. 7 is a view of the operation state of the door lock device while a door is opened.

As shown in FIGS. 4 and 6, the operation rod assembly 80 is pushed toward the doorframe 20 within the housing 50 by the compressing and repulsive force of the spring 90 at a state where the door 10 is closed such that it is protruded outside of the housing 50 together with the latch bolt assembly 70. In this case, the operation piece 82 is pushed by the force applied from the spring 90 disposed on the outer peripheral surface of the rod 84 of the operation rod assembly 80, and thereby, the arc faces 78 of

the latch bolt assembly 70 become under a rotation force D1 and thus protruded to the doorframe 20.

At that time, a space between the curved portion 82b and the guiding inclined face 82a of the operation piece 82 of the operation rod assembly 80 abuts the pressurizing face 76 of the latch bolt assembly 70.

In this manner, if the first handle 12 is pulled to a direction of an arrow (2) as shown in FIG. 1 or the second handle 14 is pushed to the direction of the arrow (2) thus to open the door, an operation force F1 is applied to the plate spring 65 that is provided on the one side of the operation lever 64.

Thereby, the operation lever 64 is rotated to a direction of D3 with respect to the hinge 63, and the operation rod assembly 80 connected to the operation lever 64 is retracted in a linear movement toward a direction of D4 that becomes distance from the doorframe 20. If the operation rod assembly 80 is retracted, the latch bolt assembly 70 has a space in which it is rotated with respect to the hinge shafts 72. At that time, the latch bolt assembly 70 is rotated in a clockwise direction of D2 with respect to the hinge shafts 72 by the repulsive force from the doorframe 20 abutting the latch bolt assembly 70, thereby being inserted into the housing 50. Thereby, the door locking state is released such that the door is smoothly and easily opened to a direction of D5.

In this case, the spring 62 attached to the operation lever 64 and the spring 90 fitted around the operation rod assembly 80 are provided with spring coefficients that are determined to apply the operation force F1 that has such a force as to move the handle shaft 11 of the door.

According to the present invention, when the first and second handles 12 and 14 are pushed or pulled to slightly operate the operation lever 64, the latch bolt

assembly 70 is turned by the reaction in such a manner as to be inserted into the housing 50. As a result, the door locking state is easily released, hence smoothly opening the door just with a substantially slight force.

At that time, there is no need for rotation of the first and second handles 12 and 14, and therefore, the handles have the conventional spherical or straight shape or the shape of'A'as shown in FIG. 1. In addition thereto, of course, the handle in the present invention may have a variety of shapes.

If the force applied to the handle 12 or 14 is removed at the state where the door is opened, the operation lever 64 is turned to its original position by the force of the spring 62, and the operation rod assembly 80 is moved to the direction of the doorframe 20 by the compressing and repulsive force of the spring 90, rotating the latch bolt assembly 70 to the direction of D 1 as shown in FIG. 6 such that the latch bolt assembly 70 is protruded from the housing 50.

On the other hand, if the door 10 is closed again, the guiding inclined face 82a of the operation piece 82 that is protruded more than the latch bolt assembly 70 becomes first contacted with the doorframe 20 just before the door 10 is closed, and then, the contacted point of the guiding inclined face 82 with the doorframe 20 is moved to the arc faces 78 of the latch bolt assembly 70.

In other words, if no guiding inclined face 82a is formed, the arc faces 78 of the latch bolt assembly 70 are contacted with the wall of the doorframe 20, occupying a relatively large area to thereby form a substantially high resistance. However, if the guiding inclined face 82a is provided like the present invention, the latch bolt assembly 70 can be gently rotated and moved to the groove of the doorframe, without having a relatively large resistance.

Therefore, even though the arc faces 78 of the latch bolt assembly 70 have a

relatively sudden curvature, the latch bolt assembly 70 is slightly moved gently to the direction of the door 10 together with the operation rod assembly 80 and the spring 90 with the help of the guiding inclined face 82a of the operation piece 82 and then moved to the direction of the doorframe 20 by the elastically repulsive force of the spring 90. Thus, the latch bolt assembly 70 is fixed to the groove of the doorframe 20 such that the door locking state is made.

On the other hand, the operation lever 64 is further provided with the plate spring 65 that is formed at the free end thereof. In case of operating the first and second handles 12 and 14, the plate spring 65 is adapted to move the operation point applied to the operation lever 64 to thereby improve the motion of the operation rod assembly 80.

FIG. 8 is a sectional view taken along the line A--A in FIG. 4. As shown in FIG.

8, the hinge shafts 72 of the latch bolt assembly 70 are inserted into the hinge grooves 54 of the housing 50, and the operation piece 82 of the operation rod assembly 80 is fitted into the space of the latch bolt assembly 70.

FIGS. 9 and 10 are views of the operation states of an auxiliary lock assembly of the door lock device of the present invention. The auxiliary lock assembly 100 of the present invention is adopted when the door 10 is closed. The manipulating shaft 106 of the auxiliary lock assembly 100 is connected with the outside key device 108 of the door lock device of the present invention, as shown in FIG 1.

As shown in FIG. 9, in case where the auxiliary locking assembly 100 is not operated in the door lock device of the present invention, the manipulating shaft 106 is rotated to a direction of A1. At that time, a protruding portion 106a that is formed at one end of the manipulating shaft 106 abuts against the stopper 104 such that the stopper 104 is moved to a direction of A2. Thus, a stopper protrusion 104a that. is

formed at one end of the stopper 104 is released from the locking concave groove 84a.

As shown in FIG. 10, on the other hand, in case where the auxiliary locking assembly 100 is operated in the door lock device of the present invention, the manipulating shaft 106 is rotated to a direction of Bl. At that time, the protruding portion 106a that is formed at the one end of the manipulating shaft 106 abuts against the stopper 104 such that the stopper 104 is moved to a direction of B2. Thus, the stopper protrusion 104a that is formed at the one end of the stopper 104 is locked into the locking concave groove 84a.

Thereby, when the stopper protrusion 104a of the stopper 104 is locked into the locking concave groove 84a of the operation rod assembly 80, the operation rod assembly 80 is not moved along the longitudinal direction. As a result, the latch bolt assembly 70 is not rotatable, hence being at a safe locking state.

According to the present invention, the door lock device is easily manufactured with a relatively small number of parts and exhibits a substantially low percentage of trouble.

Also, the door lock device of this invention does not need the operation of turning a handle such that the handle can be designed in a variety of shapes, in addition to conventional spherical or straight ones.

Moreover, the door lock device of this invention opens a door just through the application of a relatively slight force of pushing or pulling the handle, which enables children or the weak people to open the door in convenient and smooth ways.

Industrial applicability As set forth in the foregoing, there is provided a door lock device that can easily open and close a door just by a relatively small linear force, that is, by pushing

or pulling a handle in one direction.

While the present invention has been described with reference to a few specific embodiments, the description is illustrative of the invention and is not to be construed as limiting the invention. Various modifications may occur to those skilled in the art without departing from the true spirit and scope of the invention as defined by the appended claims.