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(11) | EP 2 098 379 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
| published in accordance with Art. 153(4) EPC |
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| (54) | A LEVER CLAMP MECHANISM |
| (57) A lever arch mechanism comprises: a base; two first ring members attached fixedly
onto the base at one end, two first ring members being separated from and parallel
with each other; a ring assembly attached movably onto the base, the ring assembly
comprising two second ring members separated from and parallel with each other and
a bending portion bent toward the center of the base, the middle of the bending portion
projecting upwards to form a protrusion, two first ring members and two second ring
members being disposed in such a way that they face to each other respectively so
that the respective ring members facing to each other form a closed loop when the
ring assembly moves; an elastic member for pushing the ring assembly away from the
base by its elastic force; a projection extending upwards from the base; and a lever
mechanism attached rotatably onto the projection for contacting the ring assembly,
the lever mechanism being used to press the ring assembly onto the base or move the
ring assembly away from the base for closing or opening the lever arch mechanism.
A recess is formed on the bending portion at least at one side of the protrusion.
According to the invention, the lever handle may rotate at a small angle and rise
to a relatively low height when the lever arch mechanism is opened. Thus, the distal
end of the handle does not interfere with pages, which facilitates adding or removing
pages. |
Field of the Invention
Background of the Invention
[0002] A lever arch mechanism is a type of stationery widely used for retaining pages such as loose-leaf pages. A conventional lever arch mechanism comprises: a substantially flat base; two first ring members separated from each other and having an end fixedly attached onto one longitudinal side of the base, the first ring members extending generally vertically upwards from the base and bent slightly at their other end to form a bending portion; two second ring members separated from each other and having an end movably attached onto the other longitudinal side of the base, the second ring members extending generally vertically upwards from the base and bent slightly at the other end to form the other bending portion, thereby forming a closed loop by engaging with the bending portion on the other end of two first ring members when the lever arch mechanism is closed, two second ring members connected integrally with each other at their ends near the base by a connecting portion to allow two second ring members move together, the connecting portion having a generally U-shaped bending portion bent at its middle portion towards the center of the base, the middle of the bending portion slightly protruding upward to form a protrusion; a generally upstanding projection formed at the center of the base by cutting the base and bending the cut portion upwards; a leaf spring with one end attached in a groove cut in the base adjacent the other longitudinal side and the other end abutting resiliently against the underside of the generally U-shaped bending portion of the connecting portion, the leaf spring pushing the connecting portion away from the base plane to allow two second ring members move together and away from two first ring members fixedly attached, thus opening the lever arch mechanism; and a lever rotatably attached onto the projection and having a roller for abutting against the protrusion. By pressing and rotating the lever downward, the roller may resist against the upward pushing force of the leaf spring and move along a direction away from the lever handle to a position where the connecting portion presses against the base, thereby moving two second ring members together to a position where two second ring members contact with two first ring members that are attached fixedly to form a closed loop respectively. By rotating the lever upward and away from the base, the roller may move along a direction towards the lever handle to a position where it is possible to release the pressing against the connecting portion, so that the connecting portion may move away from the base under the action of the upward pushing force of the leaf spring, thereby moving two second ring members together and away from two first ring members to form an open loop respectively. As a result, the lever arch mechanism is opened.
[0003] In the conventional lever arch mechanism, when the lever arch mechanism is opened, the lever handle rotates at a large angle and rises to a high position. The distal end of the handle interferes possibly with pages when pages are added or removed from the lever arch mechanism, thus obstructing the loose-leaf pages from being added or removed from the lever arch mechanism and resulting in much inconvenience for accessing loose-leaf pages.
Summary of the Invention
[0005] The present invention is proposed in consideration of the above problems in the conventional lever arch mechanism.
[0006] Therefore, one object of the invention is to provide a lever arch mechanism in which the lever handle may rotate at a small angle and rise to a relatively low height when the lever arch mechanism is opened. Thus, the distal end of the handle does not interfere with pages, which facilitates adding or removing pages.
[0007] According to the invention, a lever arch mechanism is provided, comprising: a flat base; two first ring members attached fixedly onto the base at one end, two first ring members being separated from and parallel with each other; a ring assembly attached movably onto the base, the ring assembly comprising two second ring members separated from and parallel with each other, two second ring members connecting integrally with each other by a connecting portion, the connecting portion comprising a bending portion bent toward the center of the base, the middle of the bending portion projecting upwards to form a protrusion, two first ring members and two second ring members being disposed in such a way that they face to each other respectively so that the respective ring members facing to each other form a closed loop when the ring assembly moves; an elastic member with one end attached onto the base and the other end abutting against the ring assembly, the elastic member pushing the ring assembly away from the base by its elastic force; a projection extending upwards from the base; and a lever mechanism attached rotatably onto the projection for contacting the ring assembly, the lever mechanism being used to press the ring assembly onto the base or move the ring assembly away from the base for closing or opening the lever arch mechanism; wherein a recess is formed on the bending portion at least at one side of the protrusion.
[0008] According to one aspect of the invention, the depth of the recess is sized so that a distance between the peak of the protrusion and the valley of the recess is equal to or lager than the diameter of the steel wire from which the ring members are made.
[0009] According to other aspect of the invention, the depth of the recess is sized so that a distance between the peak of the protrusion and the valley of the recess is equal to or lager than 4.5 mm.
[0010] Moreover, according to the present invention, the inclined angle of the lever handle with respect to the lever body is as small as possible so that the lever handle does not extend to a too high position. According to the lever arch mechanism of the invention, since a recess is formed on the bending portion at least at one side of the protrusion, the lever handle may rotate at a small angle and rise to a relatively low height when the lever arch mechanism is opened. Thus, the distal end of the handle does not interfere with pages, which facilitates adding or removing pages.
Brief Description of the Drawings
[0011]
Fig.1 is an exploded perspective view of a lever arch mechanism according to a first embodiment of the invention;
Fig.2 is a one side perspective view of the lever arch mechanism according to the first embodiment of the invention in a ring-closed configuration;
Fig.3 is an other side perspective view of the lever arch mechanism according to the first embodiment of the invention in a ring-closed configuration;
Fig.4 is a bottom perspective view of the lever arch mechanism according to the first embodiment of the invention in a ring-closed configuration;
Fig.5 is a one side perspective view of the lever arch mechanism according to the first embodiment of the invention in a ring-open configuration;
Fig.6 is an other side perspective view of the lever arch mechanism according to the first embodiment of the invention in a ring-open configuration;
Fig.7 is a one side bottom perspective view of the lever arch mechanism according to the first embodiment of the invention in a ring-open configuration;
Fig.8 is an other side bottom perspective view of the lever arch mechanism according to the first embodiment of the invention in a ring-open configuration;
Fig.9A is a perspective view of the ring members of the lever arch mechanism according to the first embodiment of the invention;
Fig.9B is a front view of the ring members of the lever arch mechanism according to the first embodiment of the invention;
Fig.9C is an enlarged view of the circled portion in Fig.9B with a scale of 2:1;
Fig.9D is a top view of the ring members of the lever arch mechanism according to the first embodiment of the invention;
Fig.9E is a side view of the ring members of the lever arch mechanism according to the first embodiment of the invention;
Fig.10A is a front view of the lever arch mechanism according to the first embodiment of the invention in a ring-closed configuration;
Fig.10B is a top view of the lever arch mechanism according to the first embodiment of the invention in a ring-closed configuration;
Fig.10C is a right view of the lever arch mechanism according to the first embodiment of the invention in a ring-closed configuration;
Fig.10D is a left view of the lever arch mechanism according to the first embodiment of the invention in a ring-closed configuration;
Fig.11A is a front view of the lever arch mechanism according to the first embodiment of the invention in a ring-open configuration;
Fig.11B is a top view of the lever arch mechanism according to the first embodiment of the invention in a ring-open configuration;
Fig.11C is a right view of the lever arch mechanism according to the first embodiment of the invention in a ring-open configuration;
Fig.11D is a left view of the lever arch mechanism according to the first embodiment of the invention in a ring-open configuration;
Fig.12 is an exploded perspective view of a lever arch mechanism according to a second embodiment of the invention;
Fig.13 is a one side perspective view of the lever arch mechanism according to the second embodiment of the invention in a ring-closed configuration;
Fig.14 is an other side perspective view of the lever arch mechanism according to the second embodiment of the invention in a ring-closed configuration;
Fig.15 is a bottom perspective view of the lever arch mechanism according to the second embodiment of the invention in a ring-closed configuration;
Fig.16 is a one side perspective view of the lever arch mechanism according to the second embodiment of the invention in a ring-open configuration;
Fig.17 is an other side perspective view of the lever arch mechanism according to the second embodiment of the invention in a ring-open configuration;
Fig.18 is a one side bottom perspective view of the lever arch mechanism according to the second embodiment of the invention in a ring-open configuration;
Fig.19 is an other side bottom perspective view of the lever arch mechanism according to the second embodiment of the invention in a ring-open configuration;
Fig.20A is a perspective view of the ring members of the lever arch mechanism according to the second embodiment of the invention;
Fig.20B is a front view of the ring members of the lever arch mechanism according to the second embodiment of the invention;
Fig.20C is an enlarged view of the circled portion in Fig.20B with a scale of 2:1;
Fig.20D is a top view of the ring members of the lever arch mechanism according to the second embodiment of the invention;
Fig.20E is a side view of the ring members of the lever arch mechanism according to the second embodiment of the invention;
Fig.21A is a front view of the lever arch mechanism according to the second embodiment of the invention in a ring-closed configuration;
Fig.21B is a top view of the lever arch mechanism according to the second embodiment of the invention in a ring-closed configuration;
Fig.21C is a right view of the lever arch mechanism according to the second embodiment of the invention in a ring-closed configuration;
Fig.21D is a left view of the lever arch mechanism according to the second embodiment of the invention in a ring-closed configuration;
Fig.22A is a front view of the lever arch mechanism according to the second embodiment of the invention in a ring-open configuration;
Fig.22B is a top view of the lever arch mechanism according to the second embodiment of the invention in a ring-open configuration;
Fig.22C is a right view of the lever arch mechanism according to the second embodiment of the invention in a ring-open configuration;
Fig.22D is a left view of the lever arch mechanism according to the second embodiment of the invention in a ring-open configuration;
Fig.23 is an exploded perspective view of a lever arch mechanism according to a third embodiment of the invention;
Fig.24 is a one side perspective view of the lever arch mechanism according to the third embodiment of the invention in a ring-closed configuration;
Fig.25 is an other side perspective view of the lever arch mechanism according to the third embodiment of the invention in a ring-closed configuration;
Fig.26 is a bottom perspective view of the lever arch mechanism according to the third embodiment of the invention in a ring-closed configuration;
Fig.27 is a one side perspective view of the lever arch mechanism according to the third embodiment of the invention in a ring-open configuration;
Fig.28 is an other side perspective view of the lever arch mechanism according to the third embodiment of the invention in a ring-open configuration;
Fig.29 is a one side bottom perspective view of the lever arch mechanism according to the third embodiment of the invention in a ring-open configuration;
Fig.30 is an other side bottom perspective view of the lever arch mechanism according to the third embodiment of the invention in a ring-open configuration;
Fig.31A is a perspective view of the ring members of the lever arch mechanism according to the third embodiment of the invention;
Fig.31B is a front view of the ring members of the lever arch mechanism according to the third embodiment of the invention;
Fig.31C is an enlarged view of the circled portion in Fig.31B with a scale of 2:1;
Fig.31D is a top view of the ring members of the lever arch mechanism according to the third embodiment of the invention;
Fig.31E is a side view of the ring members of the lever arch mechanism according to the third embodiment of the invention;
Fig.32A is a front view of the lever arch mechanism according to the third embodiment of the invention in a ring-closed configuration;
Fig.32B is a top view of the lever arch mechanism according to the third embodiment of the invention in a ring-closed configuration;
Fig.32C is a right view of the lever arch mechanism according to the third embodiment of the invention in a ring-closed configuration;
Fig.32D is a left view of the lever arch mechanism according to the third embodiment of the invention in a ring-closed configuration;
Fig.33A is a front view of the lever arch mechanism according to the third embodiment of the invention in a ring-open configuration;
Fig.33B is a top view of the lever arch mechanism according to the third embodiment of the invention in a ring-open configuration;
Fig.33C is a right view of the lever arch mechanism according to the third embodiment of the invention in a ring-open configuration; and
Fig.33D is a left view of the lever arch mechanism according to the third embodiment of the invention in a ring-open configuration.
Detailed Description of the Preferred Embodiments
[0012] Figs.1 to 11 show a lever arch mechanism 100 according to a first embodiment of the invention. The lever arch mechanism 100 according to the invention comprises a generally flat base 101. Two first ring members 103 that are separated from and parallel with each other are attached fixedly onto a longitudinal side of the base 101. Two first ring members 103 substantially extend vertically upwards from the base 101 and are bent slightly at their free ends to form a bending portion respectively. A ring assembly 105 is attached movably onto the other longitudinal side of the base 101. The ring assembly 105 comprises two second ring members 105a that are separated from and parallel with each other and a connecting portion 105b for connecting integrally two second ring members 105a. Each of two second ring members 105a has a bending portion formed on its free end respectively to allow two second ring members 105a of the ring assembly 105 to engage with the corresponding one of two first ring members 103 that are attached fixedly onto the base 101 to form a closed loop. Two second ring members 105a of the ring assembly 105 are connected integrally with each other at their other ends near the base 101 by the connecting portion 105b. The connecting portion 105b has a generally U-shaped bending portion 105c bent substantially horizontally at its middle towards the center of the base, and the middle of the bending portion 105c protrudes slightly upward to form a protrusion 105d. A recess 105e is formed on the bending portion 105c at both sides of the protrusion 105d respectively. The first ring members 103 and the ring assembly 105 have a generally circular or elliptical cross section respectively, and are made from suitable materials such as steel wire or the like. The ring assembly 105 is attached movably onto the base 101 by two turned-over portions 107. Two turned-over portions 107 are formed on one side of the base 101 provided with the ring assembly 105 by cutting or punching the base and turning the cut or punched portions of the base over.
[0013] A generally upstanding projection 109 is substantially formed in the middle of the base 101 by cutting or punching the base 101 near a longitudinal side of the base provided with the ring assembly 105 and bending the cut or punched portions of the base upwards from the base. A cutout 111 (as shown in Figs 1 and 4) is left in the base 101 because the projection 109 is bent upwards. An elongated slot 113 is formed near the edge of the longitudinal side of the base provided with the ring assembly 105, and its function will be described later. One or more holes 115 may also be formed in the base for attaching the lever arch mechanism onto a cover of files or notebooks.
[0014] The lever arch mechanism 100 according to the invention further comprises a lever 117. The lever 117 comprises a lever body 117a, a lever head 117b extending obliquely and upwards from one end of the lever body 117a and a lever handle (operation end) 117c extending from other end of the lever body 117a. The lever arch mechanism 100 according to the invention also comprises a roller 119 which is preferably made from plastics. The roller 119 is attached onto a joint between the lever body 117a and the lever head 117b through a pin shaft 121.
[0015] In the assembled lever arch mechanism 100, two first ring members 103 are mounted fixedly on one longitudinal side of the base 101 by a connection such as rivets, welding or any other known connection means. Two ends of the connecting portions 105b of the ring assembly 105 are fixed movably by two turned-over portions 107 so that the ring assembly 105 is attached movably onto the base 101. The U-shaped bending portion 105c of the connecting portions 105b substantially locates near the projection 109 to movably attach the ring assembly 105 onto other longitudinal side of the base 101 so that two second ring members 105a of the ring assembly 105 align with two first ring members 103 attached fixedly. The lever 117 provided with the roller 119 is attached rotatably onto the projection 109 at the free end of the lever head 117b by a fastener 123 such as a rivet so that the roller 119 may move substantially on the bending portion 105c of the ring assembly 105. A leaf spring 125 is bended slightly into a generally arcuate shape, with one end of the leaf spring 125 inserted into the elongated slot 113 of the base 101 to be retained on the base 101, with other end located below the bending portion 105c of the ring assembly 105 and abutting resiliently against the bending portion 105c of the ring assembly 105 for pushing the bending portion 105c of the ring assembly 105 upwards by its resilience. Of course, the mounting position of the leaf spring 125 is not limited to the illustrated position as long as the leaf spring 125 can abut against the underside of the bending portion 105c. Further, the shape of the leaf spring 125 also is not limited to the illustrated shape as long as the leaf spring 125 can abut against the underside of the bending portion 105c to generate an upward pushing force.
[0016] In the ring-open configuration of the lever arch mechanism shown in Fig.5, by grasping the lever handle 117c to rotate the lever 117 downwards and towards the base, the lever head 117b may rotate clockwise around the fastener 123 from the configuration shown in Fig.5, thereby moving the roller 119 mounted onto the joint between the lever body 117a and the lever head 117b to the protrusion 105d along the bending portion 105c of the ring assembly 105 in a direction away from the lever handle 117c (i.e. moving the roller 119 from the recess 105e to the protrusion 105d), and pressing the connecting portion 105b onto the base 101 against the upward pushing force of the leaf spring 125. As a result, two second ring members 105a of the ring assembly 105 move together to a position where they contact with two opposite first ring members 103 to form two closed loops for retaining loose-leaf pages, as shown in Fig.2.
[0017] In contrast, in the ring-closed configuration of the lever arch mechanism shown in Fig.2, by grasping the lever handle 117c to rotate the lever 117 upwards and away from the base, the lever head 117b may rotate counterclockwise around the fastener 123 from the configuration shown in Fig.2, thereby moving the roller 119 mounted onto the joint between the lever body 117a and the lever head 117b from the protrusion 105d along the bending portion 105c of the ring assembly 105 in a direction towards the lever handle 117c (i.e. moving the roller 119 from the protrusion 105d to the recess 105e), and releasing the pressing of the connecting portion 105b onto the base 101. As a result, the connecting portion 105b moves away from the base 101 under the action of the upward pushing force of the leaf spring 125 so that two second ring members 105a of the ring assembly 105 move from two first ring members 103 to form two open loops for accessing loose-leaf pages.
[0018] Compared with the conventional lever arch mechanisms, since the recess 105e is formed on the bending portion 105c, the rotational angle of the lever handle 117c from the ring-open configuration to the ring-closed configuration becomes much less than that of the conventional lever arch mechanisms. Thus, the lever handle 117c does not interfere with pages retained by the lever arch mechanism. Preferably, according to the invention, the depth of the recess 105e is sized so that a distance A between the peak of the protrusion 105d and the valley of the recess 105e is equal to or lager than the diameter D of the steel wire from which the ring members are made (as shown in Fig. 9B and 9C). Furthermore, the depth of the recess 105e is preferably sized so that the distance A between the peak of the protrusion 105d and the valley of the recess 105e is equal to or lager than 4.5 mm.
[0019] To ensure that the lever arch mechanism is closed and opened properly, a depression 105f is preferably formed on the middle of the protrusion 105d to receive the roller 119 when the lever arch mechanism is closed.
[0020] Two stoppers 127a and 127b for limiting respectively the rotation ranges of the lever head 117b when the lever arch mechanism being closed and opened are provided on one side of the projection 109 facing the ring assembly. Of course, only one stopper 127b for limiting the rotation range of the lever head 117b when the lever arch mechanism being opened may be provided on the projection 109. Limiting the rotation ranges of the lever head 117b when the lever arch mechanism being closed may be performed by abutting the lever body 117a against the base 101. Preferably, the stopper 127b is used to limit the lever arch mechanism to a position where the lever arch mechanism is allowed to open at a given range.
[0021] Figs.12 to 22 show the lever arch mechanism 200 according to a second embodiment of the invention. The structure of the lever arch mechanism 200 according to the second embodiment of the invention is substantially similar to that of the lever arch mechanism 100 according to the first embodiment of the invention except that only one recess 205e is formed at one side of the protrusion 205d facing the lever handle. Parts of the lever arch mechanism 200 according to the second embodiment corresponding to parts of the lever arch mechanism 100 according to the first embodiment are indicated by the same reference numerals, plus "100". The description for the same parts will be omitted.
[0022] In the lever arch mechanism 200 according to the second embodiment of the invention, two second ring members 205a of the ring assembly 205 are connected integrally with each other at their other ends near the base by the connecting portion 205b. The connecting portion 205b has a generally U-shaped bending portion 205c bent substantially horizontally at its middle towards the center of the base, and the middle of the bending portion 205c protrudes slightly upward to form a protrusion 205d. A recess 205e is formed at one side of the protrusion 205d facing the lever handle 217c. In the second embodiment of the invention, one stopper 227b for limiting the rotation range of the lever head 217b when the lever arch mechanism being opened is preferably provided on the projection 209 adjacent the lever head, thereby limiting the lever arch mechanism to a position where the lever arch mechanism is allowed to open at a given range. Of course, two stoppers may be provided on the projection 209 in the same manner as the first embodiment.
[0023] In the ring-open configuration of the lever arch mechanism shown in Fig.17, by grasping the lever handle 217c to rotate the lever 217 downwards and towards the base, the lever head 217b may rotate clockwise around the fastener 223 from the configuration shown in Fig.17, thereby moving the roller 219 mounted onto the joint between the lever body 217a and the lever head 217b to the protrusion 205d along the bending portion 205c of the ring assembly 205 in a direction away from the lever handle 217c (i.e. moving the roller 219 from the recess 205e to the protrusion 205d), and pressing the connecting portion 205b onto the base 201 against the upward pushing force of the leaf spring 225. As a result, two second ring members 205a of the ring assembly 205 move together to a position where they contact with two opposite first ring members 203 to form two closed loops for retaining loose-leaf pages, as shown in Fig.13.
[0024] In contrast, in the ring-closed configuration of the lever arch mechanism shown in Fig.13, by grasping the lever handle 217c to rotate the lever 217 upwards and away from the base, the lever head 217b may rotate counterclockwise around the fastener 223 from the configuration shown in Fig.13, thereby moving the roller 219 mounted onto the joint between the lever body 217a and the lever head 217b from the protrusion 205d along the bending portion 205c of the ring assembly 205 in a direction towards the lever handle 217c, and releasing the pressing of the connecting portion 205b onto the base 201. As a result, the connecting portion 205b moves away from the base 201 under the action of the upward pushing force of the leaf spring 225 so that two second ring members 205a of the ring assembly 205 move from two first ring members 203 to form two open loops for accessing loose-leaf pages.
[0025] Figs.23 to 33 show the lever arch mechanism 300 according to a third embodiment of the invention. The structure of the lever arch mechanism 300 according to the third embodiment of the invention is substantially similar to that of the lever arch mechanism 200 according to the second embodiment of the invention except that one recess 305e is formed at one side of the protrusion 305d facing away from the lever handle, the lever 317 is attached rotatably onto the projection 309 at a joint between the lever body 317a and the lever head 317b by a fastener 323 such as a rivet and the roller (the abutting portion) 319 is attached onto the free end of the lever head 317b. Parts of the lever arch mechanism 300 according to the third embodiment corresponding to parts of the lever arch mechanism 200 according to the second embodiment are indicated by the same reference numerals, plus "100". The description for the same parts will be omitted.
[0026] In the ring-closed configuration of the lever arch mechanism shown in Fig.24, by grasping the lever handle 317c to rotate the lever 317 downwards and towards the base, the lever head 317b may rotate clockwise around the fastener 323 from the configuration shown in Fig.24, thereby moving the roller 319 mounted onto the free end of the lever head 317b to the recess 305e along the bending portion 305c of the ring assembly 305 in a direction away from the lever handle 317c (i.e. moving the roller 319 from the protrusion 305d to the recess 305e), and releasing the connecting portion 305b. As a result, the connecting portion 305b moves away from the base 301 under the action of the upward pushing force of the leaf spring 325 so that two second ring members 305a of the ring assembly 305 move from two first ring members 303 to form two open loops for accessing loose-leaf pages.
[0027] In contrast, in the ring-open configuration of the lever arch mechanism shown in Fig.27, by grasping the lever handle 317c to rotate the lever 317 upwards and away from the base, the lever head 317b may rotate counterclockwise around the fastener 323 from the configuration shown in Fig.27, thereby moving the roller 319 mounted onto the free end of the lever head 317b from the recess 305e along the bending portion 305c of the ring assembly 305 in a direction toward the lever handle 317c (i.e. moving the roller 319 from the recess 305e to the protrusion 305d), and pressing the connecting portion 305b onto the base 301 against the upward pushing force of the leaf spring 325. As a result, two second ring members 305a of the ring assembly 305 move together to a position where they contact with two opposite first ring members 303 to form two closed loops for retaining loose-leaf pages, as shown in Fig.27.
[0028] Compared with the conventional lever arch mechanisms, since the recesses 205e, 305e are formed on the bending portion 205c of the lever arch mechanism of the second embodiment and the bending portion 305c of the lever arch mechanism of the third embodiment respectively, the rotational angle of the lever handles 217c, 317c from the ring-open configuration to the ring-closed configuration becomes much less than that of the conventional lever arch mechanisms. Thus, the lever handles 217c, 317c do not interfere with pages retained by the lever arch mechanism. Preferably, according to the invention, the depth of the recesses 205e, 305e is sized so that a distance A between the peak of the protrusions 205d, 305d and the valley of the recesses 205e, 305e is equal to or lager than the diameter D of the steel wire from which the ring members are made (as shown in Fig. 20B, 20C, 31B and 31C). Furthermore, the depth of the recesses 205e, 305e is preferably sized so that the distance A between the peak of the protrusions 205d, 305d and the valley of the recesses 205e, 305e is equal to or lager than 4.5 mm.
[0029] Moreover, according to the present invention, the inclined angle of the lever handle with respect to the lever body is as small as possible so that the lever handle does not extend to a too high position.
[0030] Although the preferred embodiments of the invention were described in detail taken in conjunction of the accompanying drawings in a non-limiting sense, it should be understood that various changes and modifications could be made without departing from the scope defined by accompanying claims of the invention. For example, a cam rather than the roller may be mounted at the end of the lever. Further, a concave part and a convex part may be provided on the opposite free ends of the ring members for preventing the engagement of the ring members from disengaging. It is intended that all of the changes and modifications should fall into the protection scope of the invention.
a flat base;
two first ring members attached fixedly onto the base at one end, two first ring members being separated from and parallel with each other;
a ring assembly attached movably onto the base, the ring assembly comprising two second ring members separated from and parallel with each other, two second ring members connecting integrally with each other by a connecting portion, the connecting portion comprising a bending portion bent toward the center of the base, the middle of the bending portion projecting upwards to form a protrusion, two first ring members and two second ring members being disposed in such a way that they face to each other respectively so that the respective ring members facing to each other form a closed loop when the ring assembly moves;
an elastic member with one end attached onto the base and the other end abutting against the ring assembly, the elastic member pushing the ring assembly away from the base by its elastic force;
a projection extending upwards from the base; and
a lever mechanism attached rotatably onto the projection for contacting the ring assembly, the lever mechanism being used to press the ring assembly onto the base or move the ring assembly away from the base for closing or opening the lever arch mechanism;
wherein a recess is formed on the bending portion at least at one side of the protrusion.
a flat base;
two first ring members attached fixedly onto the base at one end, two first ring members being separated from and parallel with each other;
a ring assembly attached movably onto the base, the ring assembly comprising two second ring members separated from and parallel with each other, two second ring members connecting integrally with each other by a connecting portion, the connecting portion comprising a bending portion bent toward the center of the base, the middle of the bending portion projecting upwards to form a protrusion, two first ring members and two second ring members being disposed in such a way that they face to each other respectively so that the respective ring members facing to each other form a closed loop when the ring assembly moves;
an elastic member with one end attached onto the base and the other end abutting against the ring assembly, the elastic member pushing the ring assembly away from the base by its elastic force;
a projection extending upwards from the base; and
a lever mechanism attached rotatably onto the projection for contacting the ring assembly, the lever mechanism being used to press the ring assembly onto the base or move the ring assembly away from the base for closing or opening the lever arch mechanism;
wherein a recess is formed on the bending portion at least at one side of the protrusion, and the depth of the recess is sized so that a distance between the peak of the protrusion and the valley of the recess is equal to or lager than 4.5 mm.