RATCHET BAR PUSH STRUCTURE OF GREASE GUN

Abstract

A ratchet bar push structure of grease gun includes a gun body and a grease storage section. A ratchet bar is slidably disposed in the gun body and reciprocally movable as a piston to dispense grease supplied by the grease storage section out of the gun body. A pad section is movably disposed between the ratchet bar and a push member for pushing the ratchet bar as a force transmission unit. A user can change the position of the pad section to control whether an action force of the push member is transmitted to the ratchet bar. When the pad section is positioned in a padded position, the external force is applied to the ratchet bar via the pad section to push the ratchet bar. When positioned in a released position, the force transmission path is interrupted, whereby the ratchet bar will not be pushed by the push member.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a grease-dispensing device, and more particularly to a ratchet bar push structure of a grease gun.

2. Description of the Related Art

A conventional grease gun is used to dispense grease to a work piece for providing lubrication or antirust effect. The traditional grease gun can only discharge a constant amount of grease. This often fails to meet the requirement of actual operation. For overcoming this problem, U.S. Publication No. 2009/0272762 A1 discloses a two-stage grease gun, which can be operated to dispense different amounts of grease in a high-pressure low-flow mode or a low-pressure high-flow mode in accordance with the requirements of actual situations.

To speak more specifically, the two-stage grease gun of the above patent employs two grease-pushing ratchet bars with different diameters, which can move within piston chambers as pistons. In the low-pressure high-flow mode, the large-diameter grease-pushing ratchet bar is moved within the piston chamber to dispense the grease out of the grease gun. In the high-pressure low-flow mode, the small-diameter grease-pushing ratchet bar is moved within the piston chamber to dispense the grease out of the grease gun. In the structures of the above patent, a user must apply a force to both the large-diameter grease-pushing ratchet bar and the small-diameter grease-pushing ratchet bar to reciprocally move them as pistons for dispensing the grease. When the backpressure applied to the grease is greater than the discharge pressure of the large-diameter grease-pushing ratchet bar, the grease pushed by the large-diameter grease-pushing ratchet bar will flow back into the grease reservoir through a flow bypass. Under such circumstance, only the grease pushed by the small-diameter grease-pushing ratchet bar is dispensed out of the grease gun. Accordingly, the grease gun can be operated to dispense different amounts of grease in different flow modes in accordance with the requirements of different situations.

The above two-stage grease gun with flow bypass can be operated in two different flow modes to dispense different amounts of grease. However, in structure, it is necessary to additionally dispose a flow bypass in the piston chamber within which the grease-pushing ratchet bar is moved for the grease to flow back to the grease reservoir. The flow bypass must have a check function. Accordingly, the structure of such grease gun is more complicated and hard to assemble. Moreover, in both flow modes, when pushing and dispensing the grease out of the grease gun, the user must push the respective grease-pushing ratchet bars at the same time to make them synchronously reciprocally move as pistons. Therefore, it costs much strength to operate the grease gun.

SUMMARY OF THE INVENTION

It is therefore a primary object of the present invention to provide a ratchet bar push structure of a grease gun. By means of the ratchet bar push structure, a user can operate the grease gun to dispense grease in two different flow modes with less strength.

It is a further object of the present invention to provide the above ratchet bar push structure of the grease gun, which is simplified and is easy to process and assemble.

To achieve the above and other objects, the ratchet bar push structure of the grease gun of the present invention includes a gun body; a grease storage section for storing grease; a fitting section disposed in the gun body and having at least one cylindrical piston chamber, the fitting section being formed with an incoming flow passage in communication with one side of the piston chamber, the incoming flow passage being spaced from one end of the piston chamber for communicating the grease storage section with the piston chamber; a ratchet bar coaxially slidably disposed in the piston chamber, the ratchet bar having a diameter equal to an inner diameter of the piston chamber; and a push member connected to one end of the ratchet bar, which end extends out of the piston chamber for pushing the ratchet bar to axially move within the piston chamber. The ratchet bar push structure is characterized in that the push member has an end section and a slide section positioned between the end section and the end of the ratchet bar, whereby the ratchet bar is slidable along the slide section relative to the end section. The ratchet bar push structure further includes a pad section movable between a padded position and a released position. When positioned in the padded position, the pad section is positioned between the end of the ratchet bar and the end section, whereby when an external force is applied to the end section, the end section can push the ratchet bar via the pad section and make the ratchet bar synchronously move with the end section. When positioned in the released position, the pad section releases the end of the ratchet bar, whereby the ratchet bar is slidable along the slide section relative to the end section without being pushed by the end section.

The present invention can be best understood through the following description and accompanying drawings, wherein:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a preferred embodiment of the present invention;

FIG. 2 is a perspective view of a part of the preferred embodiment of the present invention;

FIGS. 3 and 4 are partially sectional views of the preferred embodiment of the present invention, showing that the pad section is positioned in the released position and only the second ratchet bar is moved as a piston;

FIGS. 5 and 6 are partially sectional views of the preferred embodiment of the present invention, showing that the pad section is positioned in the padded position and both the first and second ratchet bars are moved as pistons;

FIG. 7 is a sectional view taken along line a-a of FIG. 3;

FIG. 8 is a sectional view taken along line b-b of FIG. 5;

FIG. 9 is a perspective view of a part of another preferred embodiment of the present invention;

FIG. 10 is an end view of the other preferred embodiment of the present invention, showing that the pad section is positioned in the released position; and

FIG. 11 is an end view of the other preferred embodiment of the present invention, showing that the pad section is positioned in the padded position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Please refer to FIGS. 1 to 8. According a preferred embodiment, the ratchet bar push structure 10 of grease gun of the present invention includes a gun body 20, a grease storage section 30, a fitting section 40, a first ratchet bar 50, a second ratchet bar 60, a push member 70 and a pad section 80.

The gun body 20 and the grease storage section 30 both pertain to prior art and thus will not be further described hereinafter.

The fitting section 40 is disposed in the gun body 20 and has a cylindrical fitting body 41 with a certain length. The fitting body 41 is formed with a first cylindrical piston chamber 42 and a second cylindrical piston chamber 43 in parallel to each other. The first and second piston chambers 42, 43 axially inward extend from one end of the fitting body 41 by a certain depth. An elongated incoming flow passage 44 is formed through one side of the fitting body 41 in communication with one side of the first piston chamber 42 and one side of the second piston chamber 43. The incoming passage 44 communicates the first and second piston chambers 42, 43 with an internal grease reservoir of the grease storage section 30. The first piston chamber 42 has an inner diameter larger than that of the second piston chamber 43.

The first ratchet bar 50 is coaxially slidably disposed in the first piston chamber 42 and is reciprocally movable within the first piston chamber 42 as a piston. The first ratchet bar 50 has a main bar body 51 coaxially slidably disposed in the first piston chamber 42. The main bar body 51 has a diameter equal to the inner diameter of the first piston chamber 42. A rectangular end piece 52 with a noncircular cross section is fixedly connected to an end of the main bar body 51, which end extends out of the first piston chamber 42. The end piece 52 axially extends from the end of the main bar body 51. The end piece 52 has a minimum outer diameter smaller than the diameter of the main bar body 51.

The second ratchet bar 60 is coaxially slidably disposed in the second piston chamber 43 and is reciprocally movable within the second piston chamber 43 as a piston. The second ratchet bar 50 has a diameter equal to the inner diameter of the second piston chamber 43. One end of the second ratchet bar 60 extends out of the second piston chamber 43.

The push member 70 has an end section 71 and a slide section 72. One end of the slide section 72 is connected to the end section 71, while the other end of the slide section 72 is coaxially slidably connected to one end of the first ratchet bar 50, whereby the first ratchet bar 50 is reciprocally extensibly/retractably slidable relative to the end section 71.

To speak more specifically, the end section 71 is substantially in the form of a plate and is perpendicularly fixedly connected to the second ratchet bar 60. The end section 71 is also connected to the first ratchet bar 50 via the slide section 72. Accordingly, a user can press a press lever 21 of the gun body 20 against the end section 71 for forcedly moving the first and second ratchet bars 50, 60.

The slide section 72 has a slide rod 721. One end of the slide rod 721 is fixedly connected to the end section 71. The end piece 52 is formed with a slide socket 722 inward extending from a free end of the end piece 52 by a certain length into the main bar body 51. The slide rod 721 is coaxially slidable fitted in the slide socket 722.

The pad section 80 is a block body 81 with a certain thickness. One face of the pad section 80 is attached to a face of the end section 71. The block body 81 is rotatably connected with the slide rod 721, whereby the block body 81 is rotatable around an axis of the slide rod 721 between a padded position and a released position. The other face of the block body 81 is recessed to form a notch-like receiving space 82 with a shape complementary to the cross-sectional shape of the end piece 52. The receiving space 82 inward extends from the other face of the block body 81. When the block body 81 is positioned in the released position, an opening of the receiving space 82 correspondingly complementarily faces the free end of the end piece 52. Under such circumstance, the end piece 52 can be slid through the opening of the receiving space 82 into the receiving space 82. When the block body 81 is positioned in the padded position, the opening of the receiving space 82 crosses the free end of the end piece 52. Under such circumstance, the end piece 52 cannot be fitted into the receiving space 82 and the end face of the free end of the end piece 52 abuts against the other face of the block body 81.

According to the above arrangement, a user can selectively operate the ratchet bar push structure 10 of the grease gun in a double-flow discharge mode. To speak more specifically, when it is necessary to dispense a large amount of grease, a user can position the pad section 80 in the padded position where the block body 81 is sandwiched between the free end of the end piece 52 and the end section 71. In this case, when the user applies a force to the press lever 21, the end section 71 not only drives the second ratchet bar 60 fixedly connected to the end section 71 to move within the second piston chamber 43 as a piston, but also forces the end piece 52 via the pad section 80 to drive the first ratchet bar 50 to move within the first piston chamber 42 as a piston. Accordingly, the grease contained in the first and second piston chambers 42, 43 can be synchronously pushed out and dispensed by a large amount.

In the case that only a small amount of grease needs to be dispensed, the user only needs to shift and rotate the block body 81 with a finger from outer side and make the block body 81 move from the padded position to the released position. At this time, when applying a force to the press lever 21, only the second ratchet bar 60 fixedly connected with the end section 71 can be moved to dispense a smaller amount of grease. In the meantime, with respect to the first ratchet bar 50, the end section 71 does not abut against the end of the first ratchet bar 50. Therefore, even if the end section 71 is pressed by the press lever 21 to move, the end piece 52 can only extend into the receiving space 82 by a different depth without making the first ratchet bar 50 axially reciprocally move as a piston.

Accordingly, a user can control the amount of the grease dispensed from the grease gun in accordance with the actual requirement. In comparison with the conventional technique, by means of the ratchet bar push structure 10 of grease gun of the present invention, when dispensing the grease in the small-amount mode, it is unnecessary to apply a force to the first ratchet bar 50 to move the same. Therefore, in comparison with the conventional technique, when using the grease gun of the present invention to dispense grease, much strength is saved. Moreover, in structure, the present invention is free from any flow bypass as in the conventional technique so that it is easier to process and assemble the present invention.

In the above structure, a user needs to operate and rotate the block body of the pad section from outer side and make the block body move between the padded position and the released position. However, in the above embodiment, only a very small part of the block body is exposed to the outer side. Therefore, it is inconvenient for a user to operate the block body. To overcome this shortcoming and facilitate the operation of the user, FIGS. 9 to 11 show another preferred embodiment of the present invention in which an edge of the end section 71′ of the push member 70′ is formed with an arched notch 711′ with a certain length. In addition, the pad section 80′ has a first extension section 811′ axially extending from one end of the block body 81′ across into the notch 711′ by a certain length. Accordingly, on one hand the area of the exposed part of the block body 81′ is increased to facilitate the operation of the user and on the other hand the first extension section 811′ is restricted within the notch 711′ so as to restrict the block body 81′ to only rotate between the padded position and the released position.

Certainly, in order to make the operation more convenient, the size of the forced part can be further enlarged. Therefore, in this embodiment, the pad section 80′ further has a second extension section 812′ outward perpendicularly extending from an end of the first extension section 811′. In this case, the user can more conveniently operate the pad section 80′.

The above embodiments are only used to illustrate the present invention, not intended to limit the scope thereof. Many modifications of the above embodiments can be made without departing from the spirit of the present invention.

Claims

1. A ratchet bar push structure of grease gun, comprising:

a gun body;

a grease storage section for storing grease;

a fitting section disposed in the gun body and having at least one cylindrical piston chamber, the fitting section being formed with an incoming flow passage in communication with one side of the piston chamber, the incoming flow passage being spaced from one end of the piston chamber for communicating the grease storage section with the piston chamber;

a ratchet bar coaxially slidably disposed in the piston chamber, the ratchet bar having a diameter equal to an inner diameter of the piston chamber; and

a push member connected to one end of the ratchet bar, which end extends out of the piston chamber for pushing the ratchet bar to axially move within the piston chamber, the ratchet bar push structure being characterized in that the push member has an end section and a slide section positioned between the end section and the end of the ratchet bar, whereby the ratchet bar is slidable along the slide section relative to the end section, the ratchet bar push structure further comprising a pad section movable between a padded position and a released position, when positioned in the padded position, the pad section being positioned between the end of the ratchet bar and the end section, whereby when an external force is applied to the end section, the end section can push the ratchet bar via the pad section and make the ratchet bar synchronously move with the end section, when positioned in the released position, the pad section releasing the end of the ratchet bar, whereby the ratchet bar can slide along the slide section relative to the end section without being pushed by the end section.

2. The ratchet bar push structure of the grease gun as claimed in claim 1, wherein the slide section has a slide rod, one end of the slide rod being fixedly connected to the end section, the end of the ratchet bar being formed with a slide socket inward axially extending from the end of the ratchet bar by a certain depth, the slide rod being coaxially slidable fitted in the slide socket.

3. The ratchet bar push structure of the grease gun as claimed in claim 2, wherein the ratchet bar has a main bar body, the main bar body having a diameter equal to the inner diameter of the piston chamber, an end piece with a noncircular cross section being fixedly connected to an end of the main bar body, the end piece extending from the end of the main bar body along an axis of the main bar body, the end piece having a minimum outer diameter smaller than the diameter of the main bar body.

4. The ratchet bar push structure of the grease gun as claimed in claim 3, wherein the pad section is a block body, one face of the block body being attached to the end section, the block body being rotatably connected with the slide rod, whereby the block body is rotatable around an axis of the slide rod between the padded position and the released position, the other face of the block body being recessed to form a receiving space with a shape complementary to the cross-sectional shape of the end piece, the receiving space inward extending from the other face of the block body by a certain depth, whereby when the block body is positioned in the released position, an opening of the receiving space correspondingly complementarily faces the end piece, permitting the end piece to slide through the opening of the receiving space into the receiving space, while when the block body is positioned in the padded position, the opening of the receiving space crosses a free end of the end piece so that the end piece cannot be slid into the receiving space through the opening thereof and an end face of the free end of the end piece abuts against the other face of the block body.

5. The ratchet bar push structure of the grease gun as claimed in claim 4, wherein the end piece has a substantially rectangular cross section and the receiving space has the form of a notch corresponding to the end piece.

6. The ratchet bar push structure of the grease gun as claimed in claim 4, wherein the end section of the push member is formed with a notch and the pad section has a first extension section outward extending from the block body across into the notch.

7. The ratchet bar push structure of the grease gun as claimed in claim 6, wherein the pad section further has a second extension section outward extending from the first extension section.