Multi-section controlled auxiliary fittings to be attached to a wrench

A multi-speed drive accessory for a tool which includes a first shaft, an output shaft, and a clutch for selectively engaging the first shaft with a coupling member driving a transfer shaft. The output shaft and the transfer shaft each include several gears which are selectively engageable with each other to establish different speed ratios in response to axial movement of the transfer shaft relative to the output shaft. A detent or latching arrangement is also provided to hold the transfer shaft in each axial position establishing one of the speed ratios.

BACKGROUND OF THE INVENTION 
The present invention is a multi-speed drive accessory for a tool. More 
specifically, the present invention is an accessory or supplemental device 
for selectively providing multiple speed outputs for a tool such as a 
wrench. 
Generally speaking, a single function is usually found in the operation or 
application of an ordinary wrench having a hexagonal head. No matter 
whether it is a hexagonal wrench, a shifting wrench or a universal wrench, 
when is revolved for one circle, the screw will also revolve for one 
circle. Therefore, such ordinary wrenches are found to lack a rapid 
assembling or disassembling function. As a solution electrical or 
pneumatic automatic wrench is invented. Although an automatic type of 
wrench can achieve a rapid assembling or disassembling function, it will 
be of no effect if the screw happens to be disengaged with the thread or 
frozen as a result of rusting since its torque force is not variable and 
other methods such as the use of a lever, or raising its temperature by 
heating to produce an expansion/shrinkage effect of unfixing the screw 
will have to be employed. Therefore, it is concluded that defects are 
inevitably found in various kinds of tools, particularly when such tools 
are lacking of any supplementary device that makes perfect work quite 
impossible. 
In view of the aforementioned defects, the inventor has devoted himself in 
a continuous research and renovation, and managed to successfully develop 
a multi-speed controlled accessory or supplemental device for a wrench, by 
means of which a more perfect work can be achieved. 
SUMMARY OF THE INVENTION 
The present invention is a multi-speed drive accessory for a tool which 
includes a first shaft, an output shaft, and clutch means for selectively 
engaging the first shaft with a coupling member driving a transfer shaft. 
The output shaft and the transfer shaft each include a plurality of gears 
selectively engageable with each other to establish different speed ratios 
in response to axial movement of the transfer shaft relative to the output 
shaft. A detent or latching arrangement is also provided to hold the 
transfer shaft in each axial position establishing one of the speed 
ratios. 
The present invention provides a number of advantages which include: use 
with various types of tools, different speed ratios may be selected for 
different purposes, and it may be used with various types of tool heads to 
install and withdraw different types of fasteners. 
These and other objects, features and advantages of the present invention 
will become more fully apparent from the following detailed description of 
the preferred embodiment taken in conjunction with the appended claims and 
the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
As indicated in FIG. 1, the present invention comprises an input shaft 1, 
an output or driving shaft 5 and a variable speed shaft 6. The first 
covered a main shaft 1, has one end made in the shape of a hexagonal lever 
and is mainly used to sleeve and couple with various type of wrenches. The 
other end of the main shaft 1 is a circular concave/convex vertical tooth 
profile arrangement, in which a circular hole 13 is set, having a spring 2 
and a springing body 3 set inside. The main shaft coupling gear 4 is 
comprised of two gears 41, 42 with each gear of a different dimension. One 
of its ends i.e. a contact end with main shaft 1, is having a gear 43 
which is also circular in shape and or a circular concave/convex vertical 
tooth profile arrangement, which will match and be driven in accordance 
with the motion of the main shaft 1 to form a clutch installation a hollow 
circular hole 44 is set in the other end of gear set 41, 42. The 
forementioned hole 44 provides an access for sleeving through a driving 
shaft 5. Both of the shaft 5 and gear 41 are loosely engaged, so as not to 
hinder the revolving of the other. Three gear units 51, 52 and 53 of 
different dimensions are set at the driving shaft 5 to operate in engage 
with a gear unit of a variable speed shaft 6 for different speed 
combinations. In their right order is gear 51 at a change speed ratio of 
1:7. It is, therefore, regarded as a quick speed section. The next gear 
52, the speed of is 1:1. It is regarded as an equal speed section. The 
third is gear 53 which provides a speed ratio of 2:1 and is regarded as a 
slow speed section. However, its twisting force has been increased one 
time. At the other end of driving shaft 5 i.e. the output end, is a socket 
54. 
The variable speed shaft 6 is also comprised of three variable speed gear 
units. In their right order is gear 61 to engage with gear 51. Next comes 
gear 62 which engages with gear 52. The third one is gear 63 which engages 
with gear 53. Their inter linking-up will produce a variable speed 
function. A driven gear 64 is also attached with variable speed shaft 6. 
The forementioned driven gear 64 mainly engages with gear 42 of main shaft 
coupling gear 4 in such a way that it receives a twisting force passed by 
main shaft 1 and further pass the said force to the driving shaft 5 
through the different speed sections of the variable speed gears 68, 62 
and 6 of variable speed shaft 6. The variable speed shaft 6 is having 
three circular arc grooves, namely groove 65 which exerts a control over 
the quick speed section, groove 66 which controls the equal speed section 
and groove 67 which controls the slow speed section. Also set is a 
positioning ball 8 and a spring 7 which function to engage one of the 
grooves 65-67 and hold the shaft 6 stationary in each of the various speed 
sections. 
The structural assembly and the application of its functions are 
illustrated in FIG. 2. When the present invention is not being used, the 
springing ball body 3 and spring 2 will cast the main shaft 1 away from 
the driving shaft 5 to cause the tooth profile arrangement 43 12 of the 
main shaft 1 to separate from the opposed tooth profile arrangement of the 
main shaft coupling gear 4, so that the clutch of the main shaft will be 
in idle running. When the present invention, is to be used a pressure is 
exerted on main shaft 1, i.e. to exert a pressure downward to turn the 
screw, the tooth profile arrangement 12 of main shaft 1 will engage with 
the tooth profile arrangement 43 of main shaft coupling gear 4, and torque 
applied to the main shaft is further conveyed to the variable speed gear 
61 of the variable speed shaft 6, and then further conveyed to the gear 51 
of the driving shaft 5 and, last of all, will be conveyed from socket 54 
to the screw. The route of torque transmission is indicated by the dashed 
line in FIG. 3. At this time, owing to the fact the gear 61 of variable 
speed shaft 6 and the gear 51 of driving shaft 5 engage at a speed ratio 
of 1:7, it is being operated under a quick speed section. Therefore, when 
the main shaft 1 is revolving for one circle, the driving shaft 5 can 
revolve for seven circles, and is thus capable of achieving the object of 
rapidly installing or unfixing a screw. 
As indicated in FIG. 4, when variable speed shaft 6 is moved toward the 
left, i.e. the positioning ball 8 and grooves are out of interengagement, 
gear 61 will separate from main shaft coupling gear 4 and gear 51. Gear 64 
and main shaft coupling gear 42 will then engage with each other and gear 
62 will engage. At this time, the matching ratio of the gear 52 to gear 53 
1:1 and it is operating in an equal speed section. That is, when the main 
shaft 1 is revolving for one circle, the driving shaft 5 is also revolving 
for one circle. The route of torque transmission is indicated by the 
dashed line. 
As indicated in FIG. 5, the variable speed shaft 6 may again be moved 
toward the left to cause the positioning ball 8 to engage with groove 67 
and gear 62 will be separated from gear 52 and cause gear 63 to engage 
with gear 53. At this time, the matching ratio of the gear 53 to gear 63 
is 2:1. It is operating as a slow speed section. that is to say, when main 
shaft 1 is revolving for one circle, the driving shaft 5 will only revolve 
for half a circle. However, the twisting force of driving shaft 5 will be 
increased one time. When the screw happened to be disengaged with the 
thread or frozen as a result of rusting, it can be easily unfixed. In the 
same manner, it can be easily screwed tightly without applying too large a 
force. 
The present invention provides a supplemental or accessory device which is 
applicable to various kinds of tools, such as an adjustable wrench, 
hexagon wrench, universal wrench or automatic type of wrench. As for the 
output shaft part denoting by the socket 54, it is applicable to various 
kinds of tools, such as the cross-head type screw driver 91, the phillips 
type screw driver 92, the small sized internal hexagonal socket 93, the 
large sized internal hexagonal socket 94, the small sized hexagonal screw 
driver 95, and the large sized hexagonal screw driver 96, shown as by 
FIGS. 6A-6F respectively. 
Summarizing the above-mentioned description, it can be seen that the 
present invention provides a novel and meritorious multi-section 
controlled supplementary device for a wrench.