Focusing device and a telescopic tube module thereof

A focusing device and a telescopic tube module thereof are for use with optical equipment. The focusing device has a base module and a telescopic tube module. The base module has a housing, a shaft, and at least two bearings. The telescopic tube module has a tubular body, a bottom reinforced member, and an upper reinforced member. The bottom reinforced member is a reinforced board. The upper reinforced member includes at least two reinforced strips. The tubular body is slidably disposed in the housing. The shaft supports the bottom reinforced member. The at least two bearings support the upper reinforced member. When the shaft drives the tubular body to move, the stability and the precision of the focusing device are improved, and the durability of the tubular body is improved.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a focusing device and a telescopic tube module thereof, and more particularly, to a focusing device and a telescopic tube module thereof for use with optical equipment such as telescopes or microscopes.

2. Background of the Invention

Telescopes are commonly used for many different purposes and by many different kinds of people, from amateur stargazers and enthusiasts catching a glimpse of astrological phenomena, to scientists conducting academic research. A telescope has a focusing device for adjusting an image of a viewed object, such as a star or a migratory bird, to the focus position of the telescope. As such, the viewed object can be seen distinctly. Therefore, the stability and the precision of the focusing device determine the quality of the telescope.

FIG. 1andFIG. 2show a conventional focusing device including a seat assembly30, a shaft31, two turn-knob mechanisms32, a sleeve assembly33, and a telescopic tube34. The seat assembly30includes a seat (not labeled). The shaft31is pivotally disposed in the seat. Inner ends of the two turn-knob mechanisms32are respectively assembled on two ends of the shaft31and pivotally disposed in the seat. The sleeve assembly33includes a sleeve (not labeled). The sleeve is assembled on the seat. The telescopic tube34is slidably disposed in the sleeve. The focusing device is assembled in optical equipment such as telescopes and corresponds to an optical axis of an objective lens assembly of the telescope. When focusing, one of the turn-knob mechanisms32is rotated, so that the shaft31drives the telescopic tube34to move back and forth.

As the seat assembly30and the sleeve assembly33of the above conventional focusing device need to be manually assembled, the number of components thereof is increased and rather complex. As a result, errors in assembly are more likely, costs are increased, and the appearance of the focusing device less attractive. Maintenance work is also more costly and time-consuming.

FIG. 3andFIG. 4show another conventional focusing device including a base module40and a telescopic tube47. The base module40includes a housing41, a shaft42, two turn-knob mechanisms43, a support plate44, two support elements45, and at least two bearings46. The housing41has an inner surface (not labeled) and a passageway (not labeled) formed in the inner surface. The shaft42is pivotally disposed in a bottom portion of the housing41and perpendicular to a longitudinal axial direction of the passageway. The shaft42has a part located in the passageway. The two turn-knob mechanisms43have inner ends being respectively assembled on two ends of the shaft42. The support plate44is disposed between the bottom portion of the housing41and the shaft42. The two support elements45are screwed in the bottom portion of the housing41and push the support plate44upward. The at least two bearings46are respectively and symmetrically disposed on an upper-left portion and an upper-right portion of the inner surface of the housing41. The telescopic tube47is slidably disposed in the passageway along the longitudinal axial direction thereof. When focusing, one of the turn-knob mechanisms43is rotated, so that the shaft42drives the telescopic tube47to move back and forth.

The telescopic tube47is made of aluminum, and the shaft42and the bearings46are made of steel. When the two support elements45push the support plate44upward, the support plate44pushes the shaft42upward to contact the telescopic tube47. As the hardness of the shaft42is greater than that of the telescopic tube47, the telescopic tube47is compressed to form a rough and uneven surface. Also, as the hardness of the bearings46is greater than that of the telescopic tube47, the telescopic tube47is compressed to form two concave lines. As a result, the stability and the precision of the focusing device are affected.

Still another conventional focusing device uses a mechanism of gears to drive its telescopic tube to move back and forth. However, there are gaps between the gears. Furthermore, vibrations greatly affect the stability and the precision of the focusing device.

SUMMARY OF THE INVENTION

The primary object of the invention is therefore to specify a focusing device and a telescopic tube module thereof to improve the stability and the precision thereof, to improve the durability thereof, to reduce costs thereof, and to make the appearance thereof more aesthetically pleasing.

According to the invention, the object is achieved via a focusing device. The focusing device comprises a base module and a telescopic tube module. The base module includes a housing, a shaft, and at least two bearings. The housing has an inner surface and a passageway formed in the inner surface. The shaft is pivotally disposed in a bottom portion of the housing and perpendicular to a longitudinal axial direction of the passageway. The shaft has a part located in the passageway. The at least two bearings are respectively disposed on an upper-left portion and an upper-right portion of the inner surface of the housing. The telescopic tube module includes a tubular body, a bottom reinforced member, and an upper reinforced member. The bottom reinforced member is disposed on a bottom portion of an outer surface of the tubular body and extends along a longitudinal axial direction of the tubular body. The upper reinforced member is disposed on an upper-left portion and an upper-right portion of the outer surface of the tubular body. The upper reinforced member forms at least two rails respectively located on the upper-left portion and the upper-right portion of the outer surface of the tubular body and extending along the longitudinal axial direction of the tubular body. The tubular body is slidably disposed in the passageway along the longitudinal axial direction thereof. The shaft supports the bottom reinforced member. The at least two bearings respectively support the at least two rails of the upper reinforced member.

The hardness of the bottom reinforced member and the hardness of the upper reinforced member are greater than that of the tubular body, so that when the shaft drives the tubular body to move, the stability and the precision of the focusing device are improved. Moreover, the durability of the tubular body is improved.

In the preferred embodiment, the bottom reinforced member is a reinforced board.

In the preferred embodiment, the at least two bearings are respectively and symmetrically disposed on the upper-left portion and the upper-right portion of the inner surface of the housing. The upper reinforced member of the telescopic tube module includes at least two reinforced strips. The at least two reinforced strips are respectively and symmetrically disposed on the upper-left portion and the upper-right portion of the outer surface of the tubular body. The at least two rails are respectively formed on the at least two reinforced strips and extend along the longitudinal axial direction of the tubular body. The at least two bearings respectively support the at least two rails of the at least two reinforced strips.

In the preferred embodiment, two imaginative lines respectively connect the at least two bearings to a central line of the passageway and form an angle of 120 degrees. Another two imaginative lines respectively connect the at least two rails to a central line of the tubular body and form an angle of 120 degrees.

In the preferred embodiment, the base module includes another two bearings. The four bearings are respectively and symmetrically disposed on a front end of the upper-left portion, a rear end of the upper-left portion, a front end of the upper-right portion, and a rear end of the upper-right portion of the inner surface of the housing. The four bearings respectively support the at least two rails.

In the preferred embodiment, the at least two bearings are respectively and symmetrically disposed on the upper-left portion and the upper-right portion of the inner surface of the housing. The upper reinforced member of the telescopic module includes a curved reinforced plate. The curved reinforced plate has a left side and a right side being respectively and symmetrically disposed on the upper-left portion and the upper-right portion of the outer surface of the tubular body. The at least two rails are respectively formed on the left side and the right side of the curved reinforced plate and extend along the longitudinal axial direction of the tubular body. The at least two bearings respectively support the at least two rails of the left side and the right side of the curved reinforced plate.

In the preferred embodiment, the housing has a seat and a sleeve formed integrally. The shaft is pivotally disposed in the seat. The inner surface and the passageway are formed in the sleeve. Therefore, compared to the prior art the precision of the focusing device is much better, the costs of the focusing device are reduced, and the appearance of the focusing device is more aesthetically pleasing.

According to the invention, the object is achieved via a telescopic tube module of a focusing device. The telescopic tube module comprises a tubular body and a reinforced member. The reinforced member is disposed on an outer surface of the tubular body. The reinforced member forms at least two rails extending along a longitudinal axial direction of the tubular body. Two imaginative lines respectively connect the at least two rails to a central line of the tubular body and form an angle that is larger than 0 degrees and smaller than 180 degrees.

To provide a further understanding of the invention, the following detailed description illustrates embodiments and examples of the invention. Examples of the more important features of the invention thus have been summarized rather broadly in order that the detailed description thereof that follows may be better understood, and in order that the contributions to the art may be appreciated. There are, of course, additional features of the invention which will be described hereinafter and which will form the subject of the claims appended hereto.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIGS. 5-8show a first embodiment of the present invention. The present invention provides a focusing device and a telescopic tube module thereof. The focusing device comprises a base module1and a telescopic tube module2.

The base module1includes a housing10, a shaft11, two turn-knob mechanisms12, a fastener13, two support elements14, and a bearing seat15. The housing10has an inner surface101and a passageway102formed in the inner surface101. In this embodiment, the housing10has a seat103and a sleeve104formed integrally. However, the housing10may have a seat and a sleeve assembled together (referring toFIG. 1andFIG. 2). The inner surface101and the passageway102are formed in the sleeve104.

A bottom portion of the housing10has a through hole105(such as a screw hole) communicating with the passageway102. The bottom portion of the housing10has two pivotal holes106respectively disposed in a left side and a right side thereof and communicating with the passageway102. The bottom portion of the housing10further has two through holes107(such as two screw holes) respectively communicating with the two pivotal holes106.

The shaft11penetrates through the two pivotal holes106. The two turn-knob mechanisms12have inner ends being respectively assembled on two ends of the shaft11and pivotally disposed in the two pivotal holes106, so that the shaft11is pivotally disposed in the seat103of the bottom portion of the housing10and perpendicular to a longitudinal axial direction of the passageway102. The shaft11has a part located in the passageway102. The two turn-knob mechanisms12have outer ends being disposed outside the bottom portion of the housing10. Each of the turn-knob mechanisms12further has a rubber ring121surrounding the outer end of the corresponding turn-knob mechanism12, so that the operation of the two turn-knob mechanisms12is much easier.

The fastener13(such as a bolt) is screwed in the through hole105. The two support elements14(such as two screws) are respectively screwed in the two through holes107and respectively push the inner ends of the two turn-knob mechanisms12upward.

The bearing seat15is assembled on an upper portion of the inner surface101of the housing10and has at least two bearings151. The at least two bearings151are respectively disposed on an upper-left portion (seeFIG. 6) and an upper-right portion (seeFIG. 7) of the inner surface101of the housing10. As shown inFIG. 9, in this embodiment, the at least two bearings151are respectively and symmetrically disposed on the upper-left portion and the upper-right portion of the inner surface101of the housing10, and two imaginative lines respectively connect the at least two bearings151to a central line of the passageway102and form an angle A of 120 degrees. However, the angle A is not restricted to the above embodiment.

The telescopic tube module2includes a tubular body20, a bottom reinforced member, and an upper reinforced member. The tubular body20may be made of aluminum. The bottom reinforced member and the upper reinforced member may be made of steel, so that the hardness of the bottom reinforced member and the hardness of the upper reinforced member are greater than that of the tubular body20.

The bottom reinforced member is disposed on a bottom portion of an outer surface201of the tubular body20and extends along a longitudinal axial direction of the tubular body20. In this embodiment, the bottom reinforced member is a reinforced board21. The bottom portion of the outer surface201of the tubular body20has a concave slot202. The telescopic tube module2further includes a plurality of fixing elements23, and the fixing elements23penetrate through a front end and a rear end of the reinforced board21and are secured in the tubular body20. As such, the reinforced board21is disposed in the concave slot202of the bottom portion of the outer surface201of the tubular body20, and the reinforced board21extends along the longitudinal axial direction of tubular body20.

The upper reinforced member is disposed on an upper-left portion and an upper-right portion of the outer surface201of the tubular body20. The upper reinforced member forms at least two rails respectively located on the upper-left portion and the upper-right portion of the outer surface201of the tubular body20and extending along the longitudinal axial direction of the tubular body20. Two imaginative lines respectively connect the at least two rails to a central line of the tubular body20and form an angle that is larger than 0 degrees and smaller than 180 degrees.

In this embodiment, the upper reinforced member includes at least two reinforced strips22. Both the upper-left portion and the upper-right portion of the outer surface201of the tubular body20have an elongated slot203, and the elongated slots203are symmetrical with each other. The telescopic tube module2further includes a plurality of fixing elements24, and the fixing elements24penetrate through a front end and a rear end of the at least two reinforced strips22and are secured in the tubular body20. As such, the at least two reinforced strips22are respectively and symmetrically disposed in the two elongated slots203of the upper-left portion and the upper-right portion of the outer surface201of the tubular body20, and the at least two rails are formed respectively on the at least two reinforced strips22and extend along the longitudinal axial direction of the tubular body20.

Therefore, two imaginative lines respectively connect the at least two rails of the at least two reinforced strips22to a central line of the tubular body20and form an angle that is larger than 0 degrees and smaller than 180 degrees. As shown inFIG. 9, in this embodiment, two imaginative lines respectively connect the at least two rails of the at least two reinforced strips22to a central line of the tubular body20and form an angle B of 120 degrees. However, the angle B is not restricted to the above embodiment.

The tubular body20is slidably disposed in the passageway102of the housing10along the longitudinal axial direction thereof. The shaft11supports the reinforced board21(the bottom reinforced member), and the at least two bearings151respectively support the at least two rails of the at least two reinforced strips22(the at least two rails of the upper reinforced member).

In this embodiment, the bearing seat15of the base module1includes another two bearings151. The four bearings151are respectively and symmetrically disposed on a front end of the upper-left portion (seeFIG. 6), a rear end of the upper-left portion (not shown), a front end of the upper-right portion, and a rear end of the upper-right portion (seeFIG. 7) of the inner surface101of the housing10. The four bearings151respectively support the at least two rails of the at least two reinforced strips22, so the telescopic tube module2has better balance.

The focusing device of the present invention is assembled in optical equipment such as a telescope and corresponds to an optical axis of an objective lens assembly of the telescope. When focusing, the two support elements14are firstly adjusted to push the inner ends of the turn-knob mechanisms12upward, so that the shaft11contacts the reinforced board21, and the at least two rails of the at least two reinforced strips22contact the bearings151. As the hardness of the reinforced board21and the hardness of the at least two reinforced strips22are greater than that of the tubular body20, the tubular body20will not be compressed by the shaft11and the bearings151.

Next, one of the turn-knob mechanisms12is rotated, so that the shaft11drives the tubular body20to move back and forth. As the hardness of the reinforced board21is greater than that of the tubular body20, the movement of the tubular body20is more precise and easier. When a focus position is obtained, the fastener13is rotated to press against the reinforced board21, so as to ensure that the tubular body20is firmly retained.

FIG. 10shows a second embodiment of the present invention. The difference between the second embodiment and the first embodiment is the upper reinforced member. The upper reinforced member includes a curved reinforced plate25. The curved reinforced plate25may have a quadrilateral shape, a quadrilateral-framed shape, an H shape, or a U shape. In this embodiment, the curved reinforced plate25has a left side and a right side being respectively and symmetrically disposed on the upper-left portion and the upper-right portion of the outer surface201of the tubular body20. The at least two rails are respectively formed on the left side and the right side of the curved reinforced plate25and extend along the longitudinal axial direction of the tubular body20. The at least two bearings151respectively support the at least two rails of the left side and the right side of the curved reinforced plate25.

As indicated above, the focusing device and a telescopic tube module thereof of the present invention have the following advantages:

(1) The hardness of the bottom reinforced member and the hardness of the upper reinforced member are greater than that of the tubular body, so that when the shaft drives the tubular body to move, the stability and the precision of the focusing device are improved. Moreover, the durability of the tubular body is improved.

(2) Two imaginative lines respectively connect the at least two bearings to a central line of the passageway and form an angle of 120 degrees, and another two imaginative lines respectively connect the at least two rails of the at least two reinforced strips or the curved reinforced plate to a central line of the tubular body and form an angle of 120 degrees, so that the stability of the tubular body is improved.

(3) The seat and the sleeve are formed integrally, so that the precision of the focusing device is improved, the costs of the focusing device are reduced, and the appearance of the focusing device is more aesthetically pleasing.

It should be apparent to those skilled in the art that the above description is only illustrative of specific embodiments and examples of the invention. The invention should therefore cover various modifications and variations made to the herein-described structure and operations of the invention, provided they fall within the scope of the invention as defined in the following appended claims.