Abstract:
A driving shaft mechanism for a ratchet wrench is disclosed. The driving shaft mechanism is built as a spindle assembly of the ratchet wrench and has a lighting device for offering direct lighting to an operating area of the ratchet wrench. The spindle assembly prevents the lighting from being accidentally turned off when a user operates the ratchet wrench by virtue of screwing or unscrewing motions between a spindle cap and a containing part so as to allow the spindle cap to movably press on or depart from a switch controlling a switching circuit electrically connected with a lamp, and further to create a close circuit or an open circuit of the switching circuit, thus turning on or off the lamp.

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates to hand tools, and more particularly, to a driving shaft mechanism designed for a ratchet wrench and having a lighting device therein. 
     2. Description of Related Art 
     Conventionally, when using a ratchet wrench to assemble or disassemble fixing elements in dark or under conditions of poor illumination, a user needs to hold a light in one hand while a hand tool in the other for lighting up an operating area. However, it is indeed troublesome if it takes both hands to operate in assembling or disassembling tasks. That means the user needs to install the light in a proper place and keep the light directed to the operating area during assembling or disassembling tasks. 
     For overcoming aforesaid shortcomings, some has developed hand tools integrated with a lighting device, as indicated in a number of prior arts. For example, Taiwan Utility Model Patent No. 287727 discloses a lighting device built in a grip of a hand tool to present downward a light beam. Another two prior arts, Taiwan Utility Model Patent Nos. 194208 and 181988, have a lighting device set within a grip of a hand tool and the light emits toward a working end of the hand tool. Still another Taiwan Utility Model Patent No. 189542 has a lighting device set outside a grip of a hand tool with its light cast toward a working end of the hand tool. 
     As discussed above, said prior arts do not have the light cast directly onto an operating area, thus leaving the operating area dark for the purpose of operation or bring shadowed by a user&#39;s hand or anything else between the light source and the operating area. 
     In yet another prior art, Taiwan Utility Model Patent No. 151015, a lighting unit established at a working end of a ratchet wrench provides direct lighting toward an operating area of the ratchet wrench. Unfortunately, it is uneconomic to build such a lighting unit inside a metal ratchet spindle due to a highly increased cost resulting from an additional drilling process to make a spindle bore in the spindle for accommodating the lighting unit. In addition, the lighting unit composed of a lamp, an electric pin and an electric conductor slackly positioned in the spindle bore is likely to have its components loosening, thereby causing poor connection. 
     In sum, during operating aforesaid ratchet wrench, an accidental switch-off of the lighting device or unit caused by the user&#39;s hands or other articles may easily occur and result in danger because the lighting device or unit is triggered by a simple slide or rotation to a switch correspondingly controlling the lighting device or unit. In addition, the operating area may not be fully covered by the light emitting from the lighting device, and an expensive cost and a technically challenging installation may attribute to complicated structure or excess parts. 
     SUMMARY OF THE INVENTION 
     To overcome the shortcomings of the traditional hand tools in terms of their lighting structures, the present invention provides a solution of installing a lighting device on a hand tool, in particular a ratchet wrench, at an working end of the ratchet wrench for generating and directing light to an operating area under a user&#39;s control. The hand tool of the present invention is characterized in simple parts and easy installation. 
     Referring to the accompanying drawings, the present invention includes a driving shaft mechanism built as a spindle assembly of the ratchet wrench, wherein the spindle assembly comprises a shaft, a spindle, a spring, at least one battery, a spindle cap, and a switch. 
     The shaft has a through hole therein. The spindle is set within the through hole, wherein the spindle comprises a post having a lamp and two electric pins attached to the lamp, and a hollow containing part that has an open end opposite to the post and a conductive recess dented on one side wall of the containing part for accommodating a switching circuit therein. The electric pins are electrically connected to an inner bottom of the containing part and to the switching circuit respectively. 
     The spring is sleeved outside the post and retained in the through hole for providing a resilient force to the spindle. 
     The battery is equipped in the containing part and has one electrode electrically connected with the electric pin positioned and connected to the inner bottom of the containing part. 
     The spindle cap is axially mounted with the containing part, and the spindle cap exposes atop the shaft when it is nonuse, but is capable of screwing with the open end of the containing part. 
     The switch provided between atop the open end of the containing part and an interior of the spindle cap is electrically connected between the switching circuit and the other electrode of the battery. As a screwing or unscrewing motions between the spindle cap and the containing part, the interior of the spindle cap is pressed or released so as to trigger the switch and therefore creating a close circuit or an open circuit of the switching circuit. 
     The implementation of the present invention can achieve at least following objectives. 
     The most important objective of the present invention is to provide the light direct to the operating area without being blocked by any obstacles by virtue of installing the lighting device in the spindle assembly to the ratchet wrench. In addition, the present invention takes advantage of screwing and unscrewing motions between the spindle cap and the containing part controlling the switch that is able to create the close circuit or open circuit of the switching circuit so as to turn on or cut off the lamp. Therefore, during operating the ratchet wrench, the switch will not be turned off accidentally. 
     Another objective of the present invention is to provide a ball recess at one side wall of the post for accommodating a ball, wherein the shaft has a positioning hole corresponding to the ball. In cooperation with the spring giving a resilient force to the spindle, the ball recess allows a user to attach or detach tool items such as a hushing at ease. Furthermore, since the lamp is supplied within the spindle, the present invention is applicable for avoiding any interference caused by installing a circuit. 
     Another objective of the present invention is to offer the spindle that is made of a plastic material and is convenient for integral forming, thus avoiding additional cutting and drilling processes necessary for a metal material. Optionally, the spindle can also be made by a transparent or light-transmitting material for constructing a lens structure at one end of the spindle so as to change lighting distribution produced by the lamp. Otherwise, the spindle taking advantage of light refraction allows a fully light-transmitting effect for illuminating an indicator on the spindle cap. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will be best understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a perspective view of a driving shaft mechanism applied in a ratchet wrench according to the present invention; 
         FIG. 2  is a perspective view of the assembled driving shaft mechanism in the present invention; 
         FIG. 3  is an exploded view of the driving shaft mechanism in the present invention; 
         FIG. 4  shows a cross-sectional view of the driving shaft mechanism in the present invention; 
         FIG. 5  shows another cross-section view of the driving shaft mechanism in the present invention when a lighting device is turned on, and 
         FIG. 6  is another cross-section view of the driving shaft mechanism in the present invention when the lighting device is turned on. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     For the convenience of explanation of the concept of subject matter in the present invention, herein a preferred embodiment is disclosed. It is noted that all objects contained in the embodiment are described in an appropriate ratio, scale, deformation or displacement quantities applicable to the scope of explanation purpose rather than the ratio of any actual elements of the present invention. 
       FIG. 1  is a perspective view of the driving shaft mechanism applied in the ratchet wrench according to the present invention. Therein, the driving shaft mechanism is built as s a spindle assembly  10  composed of a shaft  20 , a spindle  30 , a spring  40 , a spindle cap  50  and a switch  60 . The configurations and functions of said elements are set forth in the following paragraphs. 
     The ratchet wrench has the spindle assembly  10  and an orienting bar  11  equipped at one working end thereof. The orienting bar  11  controls an orienting structure built in the working end, thus allowing a user to operate the ratchet wrench in a clockwise or counterclockwise direction and accordingly driving the spindle assembly  10  to rotate. However, when the user operates the ratchet wrench in a reverse direction, the spindle assembly  10  idles. The spindle assembly  10  further comprises the shall  20  which has a retrievable ball  13  movably provided at one lateral of the shaft  20 . The ball  13  has a protruding portion exposing atop the lateral, and the protruding portion is engaged with an interior wall of a bushing sleeved with the shaft  20  for fixing the bushing and the shall  20  firmly. 
     Referring to  FIG. 2  through  FIG. 4 , a perspective view, an exploded view and a cross-sectional view of the spindle assembly  10  in the present invention. Therein, the shaft  20  has a hollow through hole  2 . 1  and a positioning hole  22  at one lateral thereon. 
     The spindle  30  is mounted with the through hole  21  and includes a post  31  and a containing part  32 . The post  31  has a lamp  33  and two electric pins  341 ,  342 . The lamp  33  can be integrally formed inside the spindle  30  or placed at a hollow hole inside the spindle  30 . The containing part  32  is a hollow chamber and has an open end opposite to the post  31 . The containing part  32  is formed with a conductive recess  321  dented on one side wall thereof for holding a switching circuit  322 . The electric pin  341  is electrically connected to an inner bottom of the containing part  32  while the other electric pin  342  is electrically connected to the switching circuit  322 . A ball recess  35  is formed at one lateral of the post  31  for receiving the ball  13  corresponding to the positioning hole  22  located on the shaft  20  and an O-ring  36  is supplied outside the containing part  32 . 
     The spring  40  is mounted outside the post  31  and positioned in the through hole  21  for providing a resilient force to the spindle  30 , so as to allow the spindle  30  to slide axially along the through hole  21 . 
     At least one battery  41 ,  42 , or  43  is installed inside the containing part  32  with one electrode thereof electrically connected to the electric pin  341 . 
     The spindle cap  50  is axially positioned over the containing part  32  and screwed on the open end of the containing part  32 , thus allowing the spindle cap  50  to screw or unscrew with the open end; wherein, when being nonuse, the spindle cap  50  exposes atop the shaft; on the contrary; when being screwed, the spindle cap  50  drives the spindle  30  to slide along the through hole  21 . In addition, the spindle cap  50  has an indicator  51  showing whether the switching circuit  322  is a close circuit (ON) or an open circuit (OFF), and by cooperation with the O-ring  36 , the spindle cap  50  is tightly mounted with the containing part  32 . 
     The switch  60  is set between atop the open end and the interior of the spindle cap  50  and is electrically connected with the switching circuit  322  and the other electrode of the battery  41 ,  42 , or  43 . The switch  60  may be a micro-switch or a push-switch. When being screwed, the spindle cap  50  rotates and presses on the switch  60 , and in turn the switch  60  turns on the switching circuit  322  to generate electricity. 
     According to the above disclosure, by referring to the accompanying drawings, the following paragraphs explain the principle applied in the driving shall mechanism of the present invention. 
     When a user utilizes the ratchet wrench in the present invention to assemble or detach tool items such as a bushing, the user screws the spindle cap  50  so that the spindle  30  slides along the through hole  21 . As the spindle  30  slides, a space between the ball recess  35  and the positioning hole  22  is formed to contain the ball  13  movably retreating so as to allow the spindle assembly  10  to be mounted with the bushing. When the user unscrews the spindle cap  50 , the spring  40  provides a resilient force to the spindle  30  and a part of the ball  13  is forced to jut out of the positioning hole  22 . The protruding portion of the ball  13  is engaging with the interior wall of the bushing mounted with the shaft  20  for fixing the bushing and the shall  20 . 
     As shown in  FIG. 5 , when using the lamp  33 , the user may rotate the spindle cap  50  in accordance with the indicator  51 , and the spindle  30  rotates in one direction without shifting to the other direction by virtue of the ball recess  35  and the ball  13  of the spindle  30 . Thus, when the user rotates spindle cap  50 , the spindle cap  50  screws or unscrews with the open end of the containing part  32 . 
     Therefore, when the user follows the indicator  51  and rotates the spindle cap  50  toward “ON”, the spindle cap  50  screws on the open end of the containing part  32  so as to drive the spindle cap  50  to press on the switch  60 , thereby closing the loop of the switching circuit  322  to generate a light from the lamp  33 . 
     By the same token, when the user rotates the spindle cap  50  toward “OFF”, the spindle cap  50  unscrews from the open end of the containing part  32  so as to withdraw the spindle cap  50  away from the switch  60 , thereby creating opening the loop of the switching circuit  322  to turn off the light. 
     As above disclosed, the present invention offers said lighting device applied to the ratchet wrench that is effective in preventing an accidental switch-off which may result in danger in the course of operating the ratchet wrench on the strength of screwing and unscrewing motions between the spindle cap  50  and the containing part  32 . 
     As depicted in  FIG. 6 , the spindle  30  may be made by a plastic material, thus allowing the spindle  30  to be formed integrally and further saving costs from cutting and drilling processes necessary for a metal material. Alternatively, the spindle  30  may be constituted by a transparent or light-transmitting material in order to form a lens structure  37  at one end facing the lamp  33 , wherein the lamp  33  is located in the spindle  30 , and it is convenient to change a light distribution pattern of the lamp  33 . Furthermore, the spindle cap  50  may also be made with a transparent or light-transmitting material for rendering a light emitting effect in the spindle cap  50  and the spindle  30  by the virtue of refraction, so as to brighten up the indicator  51 . 
     Having thus described several aspects of at least one embodiment of this invention, it is to be appreciated that various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be part of this disclosure, and are intended to be within the spirit and scope of the invention rather than limit the scope of the present invention. Accordingly, the foregoing description and drawings are by way of example only.