Ring binder mechanism

The present invention relates to a ring binder mechanism for binding the sheets of loose leaves. The mechanism comprises an elongated spring plate that extends longitudinally and, in profile, has a shallow U-shaped configuration and opposite edges which extend substantially toward each other; two parallel elongate hinge plates supported by said spring plate for pivotal toggle motion relative to the spring plate about a central hinge line, which are mounted in parallel and retained by the opposite edges of the spring plate; and a plurality of rings for clasping said sheets of loose leaves. Each of the rings comprises a pair of half ring elements of circular cross-section which are mounted on said hinge plates, with one half ring element of each pair being attached to one of the hinge plates and the other half ring element of the pair attached to the other hinge plate, with the two half ring elements of each pair in substantial alignment.

FIELD OF THE INVENTION

The present invention relates to a ring binder mechanism for binding the sheets of loose leaves, especially to a binder mechanism with improved ring elements which can close tightly.

BACKGROUND OF THE INVENTION

A ring binder is applied to secure loose leaves, such as punched paper, into a file folder or a notebook. It is characterized by ring elements for securing paper, wherein the ring elements can be opened optionally to add or remove paper, or closed to secure paper, while allowing paper to move along them. Generally a lever is provided on both ends of the binder to move the ring elements between an opened position and a closed position.

FIGS. 20 and 21show a ring binder according to the prior art. In the conventional ring binder, end faces56of half ring elements54form an engagement configuration with a convex portion and a concave portion. When the end faces56of the two half ring elements54close, the convex portion of the end face56of one half ring element engages with the concave portion of the end face56of the other half ring element. One disadvantage of this type of engagement configuration is that the end faces can not close tightly and align to each other exactly when two half ring elements close, so that vertical and transverse misalignments for the engagement configuration will occur, as illustrated inFIGS. 20 and 21. Owing to the disadvantage that the end faces56of the binder which engage with each other misalign up and down, paper which is bound by the binder can not be turned over smoothly, and can even be torn.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a ring binder mechanism that can overcome the above mentioned disadvantages of the prior art so as to enable the ring members to close tightly and align to each other exactly and eliminate the vertical and transverse misalignment.

This object is achieved according to the present invention by providing a ring binder mechanism for binding the sheets of loose leaves, the mechanism comprising: an elongated spring plate that extends longitudinally and, in profile, has a shallow U-shaped configuration and opposite edges which extend substantially toward each other;

two parallel elongate hinge plates supported by said spring plate for pivotal toggle motion relative to the spring plate about a central hinge line, the hinge plates being mounted in parallel and retained by the opposite edges of the spring plate;

a plurality of rings for clasping said sheets of loose leaves, each of the rings comprising a pair of half ring elements mounted on said hinge plates, with one half ring element of each pair being attached to one of the hinge plates and the other half ring element of the pair attached to the other hinge plate, with the two half ring elements of each pair in substantial alignment, the pairs of half ring elements being movable with said hinge plates to toggle between an open position and a closed position and forming a substantially annular shape when in the closed position;

wherein free ends of the half ring of each pair elements form a nesting configuration when in the closed position, the free end of one half ring element of each pair having a centrally concave nesting portion and the free end of the other half ring element of the pair having a centrally convex nesting portion, said concave portion and said convex portion being symmetrical about an axis line of the respective ring elements of the pair, so that when the pair of half ring elements are in the closed condition, the free ends of the half ring elements are aligned to each other, and form a surface-engagement, so that the convex resting portion and the concave nesting portion are nested together tightly.

Preferably, the nesting portion with a centrally convex portion is formed in a free end of one half ring element of said pair of half ring elements, and the nesting portion with a centrally concave portion is formed in a free end of the other engaging half ring element, the convex nesting portion has an annular conical surface, the concave nesting portion has a conical hole that is formed from its external end surface, a diameter of the conical hole on the external end surface is smaller than that of the cylindrical rod of the half ring element, a cone angle of the conical hole is smaller than that of the annular conical surface of the centrally protruding outwards nesting portion, when the half ring elements are in the closed condition, and the connecting portion between the external end surface of the concave nesting portion and the conical hole thereof engages with the annular conical surface of the convex nesting portion, so that the centrally convex nesting portion is nested in the centrally concave nesting portion.

Preferably, the nesting portion with a centrally convex portion is formed in a free end of one half ring element of said pair of half ring elements, and the nesting portion with a centrally concave portion is formed in a free end of the other engaging half ring element, the convex nesting portion has a protruding portion, the protruding portion is connected to a surface of the cylindrical rod of the half ring element via an annulus internal end surface, a diameter of the protruding portion on the internal end surface is smaller than that of the cylindrical rod of the half ring element, the concave nesting portion has a opening that is formed from its external end surface, a diameter of the opening on the external end surface is smaller than that of the cylindrical rod of the half ring element and slightly larger than that of the protruding portion on its internal end surface, when the half ring elements are in the closed condition, and the external end surface of the concave nesting portion and the internal end surface of convex nesting portion form a surface-engagement, so that the convex nesting portion is nested in the concave nesting portion.

Preferably, the protruding portion of the convex nesting portion has a conical shape, the opening of the concave nesting portion has a conical hole that is formed from its external end surface and an internal cylindrical hole that is connected to the conical hole.

Preferably, the protruding portion of the convex nesting portion has a shape that consists of a cylindrical tip and an arc-shaped annular conical base portion, and the opening of the concave nesting portion has a conical hole that is formed from its external end surface and an internal cylindrical hole that is connected to said conical hole.

Preferably, the protruding portion of the convex nesting portion has a cylindrical shape, the opening of the concave nesting portion has a shape of an internal cylindrical hole.

Preferably, the nesting portion with a centrally convex portion is formed in a free end of one half ring element of the pair of half ring element pairs, and the nesting portion with a centrally concave portion is formed in a free end of the other engaging half ring element, the convex nesting portion has a protruding conical portion, the conical portion is connected to a surface of the cylindrical rod of the half ring element via an annulus internal end surface, a diameter of the conical portion on the internal end surface is smaller than that of the cylindrical rod of the half ring element, the concave nesting portion has a conical hole that is formed from its external end surface, a diameter of the conical hole on the external end surface is smaller than that of the cylindrical rod of the half ring element and substantially equal to that of the protruding conical portion on the internal end surface, when the half ring elements are in the closed condition, the external end surface of the concave nesting portion and the internal end surface of the convex nesting portion form a surface-engagement, and the conical portion of the convex nesting portion and the conical hole of the concave nesting portion form an engagement, so that the concave nesting portion is nested in the convex nesting portion.

Preferably, the pair of half ring elements of the ring binder mechanism form a circular ring.

Preferably, one half ring element of said pair of half ring elements of the ring binder mechanism has a straight side.

Preferably, two, three, four or more rings are provided in the ring binder mechanism.

Preferably, the rings are made of metal material, and the metal material can be steel.

Preferably, the rings are made of plastic material.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In all the above-mentioned figures, the corresponding parts are indicated by corresponding reference numbers.

Now referring to the above-mentioned figures, especially to theFIGS. 1,2and5, the ring binder mechanism according to the present invention for binding the sheets of loose leaves is generally indicated by30. This mechanism includes an elongated plate32and three rings. The three rings are generally indicated by34and used to secure the sheets of loose leaves.

The plate32has a shape, viewed from the top or bottom, of an elongated rectangle and has a substantially arc-shaped (U-shaped) cross section with a rising portion thereof along its longitudinal direction. The plate32, as shown, has two ribs that extend along the longitudinal direction in the middle thereof. The plate32has two substantially opposite longitudinal edges40and substantially opposite transverse ends. A bent bottom edge44is formed each along both of the longitudinal edges40(FIG. 2). The opposite longitudinal edges are therefore directed toward each other. The plate32can be configured in profile as an upside down “U” as shown. The elongated plate32is made of metal or any other suitable material which has enough rigidity and can provide a stable attachment for other parts of the mechanism, while light-weight, material-saving and cost-saving. Two holes46are provided in the plate32(FIG. 5) for receiving and attaching a bushing48respectively, so that the mechanism can be fastened in a file folder of a notebook. Six additional holes52are positioned along the longitudinal edges40for receiving a ring that passes therethrough respectively. Those plates or shells that have other kinds of shapes, including irregular shapes, or those mechanisms that are formed in a file folder or a notebook integrally, all fall within the scope of the present invention.

Each of the three rings34comprises two half ring elements54that can move between a closed position (FIGS. 1 and 2) and an opened position (FIGS. 3 and 4), in which in the closed position each of the ring element forms a continuously closed ring for securing sheets of loose leaves, and in the opened position each of the ring element forms a discontinuously opened ring for adding or removing sheets of loose leaves. The ring element54is formed by a substantially cylindrical rod that is made of a suitable material, such as steel. Although in the embodiment shown the two half ring elements54of each of the three rings34are both movable, a mechanism that has one movable half ring element and one fixed half ring element also falls into the scope of the present invention. Furthermore, those kinds of mechanism which have various numbers, such as more than or less than three rings all fall into the scope of the present invention.

The half ring elements54are provided on hinge plates56that are supported by the elongated plate32(FIGS. 2 and 4). The hinge plates56are provided for a pivotable movement, so as to move the ring elements between the closed position and the opened position. The hinge plates56are provided in parallel for attachment and connected in parallel to each other, so that they can pivotably rotate along the adjacent longitudinal edges. Slots60are provided in the hinge plates56for connecting to the ring elements. Each of the hinge plates56has an outer longitudinal edge62that is opposite to a fold line (FIG. 5). The longitudinal edges62are inserted into the corresponding bent bottom edges44of the elongated plate32respectively. The longitudinal edges62can move freely in the edges44respectively, so as to make the interconnected hinge plates56pivotably rotate. The elongated plate32provides a small elastic force to press the hinge plates56offset away from a common surface position (that is, to face towards the closed position or the opened position). A special control means that is generally indicated by38is provided for pivot rotating the hinge plates56in a controllable way, so as to move the ring elements between the closed position and the opened position.FIG. 6shows the ring binder mechanism shown inFIG. 1via a front view, a side view and a back view respectively.

The ring elements of the ring binder mechanism according to the present invention will be further described as follows:

FIGS. 7 and 8show a first embodiment of nesting portions156,156′ of the ring element of the ring binder mechanism according to the present invention. As shown in theFIG. 8that is a partial enlarged view, the nesting portions156,156′ that are in the closed condition have a central axis line51. The nesting portion156with a centrally convex portion along the axis line51is formed in a free end of one half ring element54. A cylindrical tip150whose diameter is smaller than that of the cylindrical rod of the half ring element54is formed on the top portion of the nesting portion156around the axis line51. The tip150is connected to a surface of the cylindrical rod of the half ring element54via an annulus conical surface151. The nesting portion156′ with centrally concave portion along the axis line51is formed in a free end of the other engaging half ring element54. The nesting portion156′ substantially forms a cylindrical hole152around the axis line51. The cylindrical hole152has a conical portion in its bottom. The diameter of the cylindrical hole152is larger than that of the top cylinder portion of the nesting portion156, but smaller than that of the cylindrical rod of the half ring element54. By a conical hole153that tapers outwards, the cylindrical hole152is connected to an external end surface154′ of the nesting portion156′ at a position adjacent to an external surface of the cylindrical pole. A diameter of the conical hole153on the external end surface154′ is slightly smaller than that of the cylindrical rod of the half ring element54. A cone angle of the conical hole of the centrally concave nesting portion156′ relative to the axis ling51is smaller than that of the annular conical surface of the centrally convex nesting portion156. When the half ring elements54are in the closed condition, as shown inFIG. 8, the connecting portion between the external end surface154′ of the concave nesting portion156′ and the conical hole153engages with the annular conical surface151of the convex nesting portion156, so that the centrally convex nesting portion156of the half ring elements54is nested in the centrally concave nesting portion156′ of the corresponding half ring elements54. In this way, the engagement between the two nesting portions is tighter and the problem that the nesting portions are misaligned can be avoided.

FIG. 9shows a second embodiment of nesting portions256,256′ of the ring element of the ring binder mechanism according to the present invention. As shown in theFIG. 9that is a partial enlarged view, the nesting portions256,256′ that are in the closed condition have a central axis line51. The nesting portion256with centrally convex portion along the axis line51is formed in a free end of one half ring element54. A cylindrical tip150whose diameter is smaller than that of the cylindrical rod of the half ring element54is formed on the top portion of the nesting portion256around the axis line51. The tip150is connected to a position of an internal end surface154of the nesting portion256that is adjacent to an external surface of the cylindrical rod of the half ring element54via an arc-shaped annulus conical surface151. The nesting portion256′ with a centrally concave portion along the axis line51is formed in a free end of the other engaging half ring element54. The concave nesting portion256′ substantially forms a cylindrical hole152around the axis line51. The cylindrical hole152has a conical portion in its bottom. The diameter of the cylindrical hole152is larger than that of the top cylinder portion of the convex nesting portion256, but smaller than that of the cylindrical rod of the half ring element54. By a conical hole153that tapers outwards, the cylindrical hole152is connected to the external end surface154′ of the nesting portion256′ at a position adjacent to an external surface of the cylindrical pole. A cone angle of the conical hole of the centrally concave nesting portion256′ relative to the axis ling51is smaller than that of the annular conical surface of the centrally convex nesting portion256. A diameter of the conical hole153on the external end surface154′ is slightly larger than that of the annulus conical surface on the internal end surface154. When the half ring elements54are in the closed condition, as shown inFIG. 9, the external end surface154′ of the concave nesting portion256′ and the internal end surface154of convex nesting portion256form a tight surface-engagement, so that the centrally convex nesting portion256of the half ring elements54is nested in the centrally concave nesting portion256′ of the corresponding half ring elements54. In this way, the engagement between the two nesting portions is tighter and the problem that the nesting portions are misaligned can be avoided.

FIG. 10shows a third embodiment of nesting portions356,356′ of the ring element of the ring binder mechanism according to the present invention. The configuration of the third embodiment is substantially similar to that of the nesting portion shown inFIG. 9. The differences is in that: instead of the cylindrical tip and the an arc-shaped annulus conical surface shown inFIG. 9, an arc-shaped conical surface151is formed on the top portion of the convex nesting portion356around the axis line51. In this way, the risk that paper is torn by the sharp edges of the nesting portions when the paper is added or removed can be eliminated.

FIG. 11shows a fourth embodiment of nesting portions456,456′ of the ring element of the ring binder mechanism according to the present invention. As shown in theFIG. 11that is a partial enlarged view, the nesting portions456,456′ that are in the closed condition have a central axis line51. The nesting portion456with centrally convex portion along the axis line51is formed in a free end of one half ring element54. A cylindrical tip150whose diameter is smaller than that of the cylindrical rod of the half ring element54is formed on the top portion of the convex nesting portion456around the axis line51. The tip150is connected to a surface of the cylindrical rod of the half ring element54via an internal end surface154of the convex nesting portion456. The nesting portion456′ with centrally concave along the axis line51is formed in a free end of the other engaging half ring element54. The concave nesting portion456′ substantially forms a cylindrical hole152around the axis line51. The cylindrical hole152has a conical portion in its bottom. The diameter of the cylindrical hole152is larger than that of the tip150of the nesting portion456, but smaller than that of the cylindrical rod of the half ring element54. The cylindrical hole152is connected to an external surface of the cylindrical rod via an external end surface154′ of the concave nesting portion456′. When the half ring elements54are in the closed condition, as shown inFIG. 11, the external end surface154′ of the concave nesting portion456′ and the internal end surface154of convex nesting portion456form a tight surface-engagement, so that the centrally convex nesting portion456of the half ring elements54is nested in the centrally concave nesting portion456′ of the corresponding half ring elements54. In this way, the engagement between the two nesting portions is tighter and the problem that the nesting portions are misaligned can be avoided.

FIG. 12shows a fifth embodiment of nesting portions556,556′ of the ring element of the ring binder mechanism according to the present invention. As shown in theFIG. 12that is a partial enlarged view, the nesting portions556,556′ that are in the closed condition have a central axis line51. The nesting portion556with centrally convex portion along the axis line51is formed in a free end of one half ring element54. A flat top frusto-conical portion150is formed on the top portion of the convex nesting portion556around the axis line51. The flat top frusto-conical portion150is connected to a surface of the cylindrical rod of the half ring element54via an internal end surface154of the convex nesting portion556. The nesting portion556′ with centrally concave portion along the axis line51is formed in a free end of the other engaging half ring element54. The concave nesting portion556′ substantially forms a flat bottom frusto-conical hole152around the axis line51. The frusto-conical hole152is connected to an external surface of the cylindrical rod via an external end surface154′ of the concave nesting portion556′. A cone angle of the frusto-conical hole of the centrally concave nesting portion556′ relative to the axis ling51is substantially equal to that of the flat top frusto-conical portion150of the centrally convex nesting portion556, and a diameter of the flat bottom frusto-conical hole152on the external end surface154′ is slightly equal to that of the flat top frusto-conical portion150on the internal end surface154. When the half ring elements54are in the closed condition, as shown inFIG. 12, the external end surface154′ of the concave nesting portion556′ and the internal end surface154of convex nesting portion556form a tight surface-engagement, so that the centrally convex nesting portion556of the half ring elements54is nested in the centrally concave nesting portion556′ of the corresponding half ring elements54. In this way, the engagement between the two nesting portions is tighter and the problem that the nesting portions are misaligned can be avoided.

FIG. 13shows a sixth embodiment of nesting portions656,656′ of the ring element of the ring binder mechanism according to the present invention. The configuration of the sixth embodiment is substantially similar to that of the nesting portion shown inFIG. 12. The difference is in that: the flat top frusto-conical portion of the nesting portion556shown inFIG. 11is replaced with an arc-shaped top frusto-conical portion shown inFIG. 13. In this way, the risk that paper is torn by the sharp edges of the nesting portions when the paper is added or removed can be eliminated.

FIGS. 14 and 15show another ring binder mechanism according to the present invention that is in a closed condition. The mechanism comprises two rings. One of the half ring elements of each of said rings has a straight side. The nesting portions of the ring elements of the ring binder mechanism also can have the configuration of the above mentioned first to sixth embodiments shown inFIGS. 7 to 13.

FIGS. 16 and 17show another ring binder mechanism according to the present invention that is in a closed condition and an opened condition, respectively. The mechanism comprises four rings. One of the half ring elements of each of said rings has a straight side, similar toFIGS. 14 and 15. The nesting portions of the ring elements of the ring binder mechanism also can have the configuration of the above mentioned first to sixth embodiments shown inFIGS. 7 to 13. In addition, those kinds of mechanism which have various numbers, such as more than or less than four rings are all fell into the scope of the present invention.

FIGS. 18 and 19show another ring binder mechanism according to the present invention that is in a closed condition and an opened condition, respectively. The mechanism comprises three rings. One of the half ring elements of each of said rings has an inclined straight side. The nesting portions of the ring elements of the ring binder mechanism also can have the configuration of the above mentioned first to sixth embodiments shown inFIGS. 7 to 13. In addition, those kinds of mechanism which have various numbers, such as more than or less than three rings, all fall into the scope of the present invention.

Because various modifications can be done without departing from the scope of the present invention, it should be understood that all the content that is included in the above description and are shown in the figures is only instructive, while not limiting the scope of the invention.