Arm mechanism

An arm mechanism to be operated at a proximal location to move a tool at a distal location. The arm mechanism includes an outer series of links and an inner series of links. Each series of links are connected together in an engaging relationship and in an in-line relationship with the outer series of links being pivotally mounted on the inner series of links. The arm mechanism is capable of being moved through almost three hundred and sixty degrees with the tool being movable in precise increments.

BACKGROUND OF THE INVENTION 
1) Field of this Invention 
The field of this invention relates to mechanisms and more particularly to 
an arm mechanism which facilitates the moving of a tool located at the 
distal end of the arm mechanism with the movement of the tool being 
affected from the proximal end of the arm mechanism. 
2) Description of the Prior Art 
Robotic types of arm mechanisms have long been known. One common use for 
such an arm mechanism would be in conjunction with an underwater vehicle. 
The arm mechanism would be located exteriorly of the vehicle but operated 
by one of the occupants of the vehicle in a manned submersible or by an 
operator located remotely in the case of an unmanned vehicle. The arm 
mechanism could be used for picking up specimens on the sea floor or 
possibly accomplishing some type of work, such as repair of some form of 
underwater structure. Similar types of arm mechanisms are used in other 
environments such as nuclear reactors. 
In the constructing of any arm mechanism certain objectives must be met in 
order to achieve a satisfactory arm mechanism. One of these objectives is 
that the arm mechanism must be positive in its operation. When commands 
are given at the proximal location of the arm mechanism to perform certain 
functions, those functions are to be performed at the distal location of 
the arm mechanism. In other words, let it be assumed that commands are 
given to operate a shovel at the distal location and a shoveling action to 
occur at a specific area of the terrain. The operative movements at the 
proximal end must result precisely in that shoveling action at the desired 
location. 
Another objective is that fine control of the tool is required. In other 
words when it is necessary for the tool to make only small movements in a 
particular direction, those small movements can be made from the operating 
mechanism at the proximal location. 
Another objective of an arm mechanism is that it should be operable over a 
wide arm range. Some arm mechanisms of the prior art can only operate over 
a very limited range and of course the greater the range of operability, 
the greater the versatility of the mechanism. 
Another objective of such an arm mechanism is to have the arm mechanism 
manufactured at a reasonable cost. In the past such arm mechanisms have 
been manufactured at an exceedingly expensive cost which greatly limits 
their usage. 
SUMMARY OF THE INVENTION 
One of the primary objectives of the present invention is to construct an 
arm mechanism which can be manufactured at a cost substantially less than 
known prior art mechanisms which therefore make the arm mechanism readily 
available for usage in certain installations that prohibited the use of 
certain prior art mechanisms because of their cost. 
Another objective of the present invention is to construct an arm mechanism 
which can be finely controlled from the proximal location so that the tool 
as utilized can be precisely precisioned and perform its work with a high 
degree of control. 
Another objective of the present invention is to construct an arm mechanism 
which is operable over an exceedingly wide range of area and actually the 
arm mechanism of the present invention is able to be used in any direction 
within three hundred and sixty degrees of the proximal location of the arm 
mechanism. 
The arm mechanism of the present invention comprises an inner series of 
links which are joined together through a gearing arrangement at each end 
thereof. This inner series of links is in essence located in a single 
plane with operation of the most proximal link in the inner series of 
links causing certain movements to occur at the most distal end of the 
series of links. Connected to this inner series of links is an outer 
series of links with the outer series of links again being located in a 
single plane and located in an end-to-end, in-line relationship with these 
links being engagingly connected together also through a series of gear 
teeth. Each outer link is pivotally connected by a single pivot pin to one 
single inner link. At the distal end the tool could be connected to either 
the distal outer link or the distal inner link. At the proximal end for 
best operative control, movement of the proximal link on the inner series 
of links is accomplished by one motor with the separate motor control 
being used to operate the proximal end of the outer series of links. Each 
motor would result in movement of the tool located at the distal end.

DETAILED DESCRIPTION OF THE SHOWN EMBODIMENT 
Referring particularly to the drawings there is shown a base 10 on which 
are mounted base stanchions 12, 14 and 16. Each base stanchion 12, 14 and 
16 actually comprise a pair of plates mounted in a spaced-apart manner. 
Pivotally mounted by a pivot pin 18 on base stanchion 12 are a pair of 
inner proximal links 20 and 22. Proximal links 20 and 22 are identical and 
operate together due to being fixed together by pivot pin 18 and pivot pin 
24. Pivot pin 18 is located in a spaced relationship from pivot pin 24. 
The inner proximal links 20 and 22 are maintained in a evenly spaced-apart 
manner by means of spacer 26 which comprises part of the pivot pin 18 and 
spacer 28 which comprises a part of the pivot pin 24. The pivot pin 18 is 
actually two separate pins which are threadably secured into the spacer 
26. In a similar manner the pivot pin 24 is actually two separate pins 
which are threadably secured into the spacer 28. It is to be understood 
that there could be more than two inner proximal links 20 and 22. As for 
example there could be three, four, five or six or however many, all 
located in an evenly spaced-apart manner and all functioning to move in 
unison. The arm mechanism of this invention could utilize just one 
proximal link but in order to give the arm mechanism adequate lateral 
strength, it is desirable to utilize two inner proximal links 20 and 22. 
The pivot pin 24 is mounted at the center relative to the width of the 
proximal links 20 and 22. 
The inner proximal link 20 terminates in a series of gear teeth 30 and its 
outer end. In a similar manner the inner proximal link 22 terminates in a 
series of gear teeth 32. The gear teeth 30 engage with gear teeth 34 of a 
intermediate inner link 36. The gear teeth 32 engage with gear teeth 38 of 
the intermediate inner link 40. The link 36 also includes a second series 
of gear teeth 42 with the inner link 40 including a second series of gear 
teeth 44. The gear teeth 42 engage with gear teeth 46 mounted on one end 
of an intermediate inner link 48. The gear teeth 44 operatively engage 
with gear teeth 50 of an intermediate inner link 52. The intermediate 
inner link 48 terminates in gear teeth 54 which operatively engage with 
gear teeth 56 of a distal inner link 58. The intermediate inner link 52 
terminates in gear teeth 60 which operatively engage with gear teeth 62 of 
a distal inner link 64. Again links 64 and 58 are identical. Both links 54 
and 58 are fixedly secured to a threaded fastener 66. The threaded 
fastener 66 is in turn fixedly mounted onto a tool 68. The tool 68 can 
comprise any common tool such as a shovel, a drill, a magnetic pickup 
device, etc. 
Links 36 and 40 are connected together to operate in unison by means of a 
pair of pivot pins 70 and 72. Pivot pin 70 includes a spacer 74 with pivot 
pin 72 including a spacer 76. The links 48 and 52 are connected together 
and made to operate in unison by means of pivot pins 78 and 80. As part of 
the pivot pins 78 and 80 there are located spacers 82 and 84 respectively 
between the links 48 and 52. The distal links 58 and 64 are similarly 
connected together by a pivot pin 86 which includes a spacer 88. 
It is to be noted that the inner links 20, 36, 48, and 58 are all connected 
in an end-to-end in-line relationship within a single plane. It is to be 
understood that the duplicate series of links 22, 40, 52, and 64 are also 
connected in the same manner and within a single plane. 
Also pivotally mounted on the pivot pin 24 is a proximal outer link 90 with 
again an identical outer proximal link 92 being also mounted on the pivot 
pin 24 and located in a spaced relationship on either side of the spacer 
28. The outer proximal link 90 has a set of inner gear teeth which are not 
shown and also a set of outer gear teeth 94. The outer link 92 has at one 
end gear teeth 96 and at the opposite end gear teeth 98. The outer 
proximal links 90 and 92 were also pivotally mounted on the pivot pin 70. 
The gear teeth 94 operatively engage with gear teeth 100 of an intermediate 
outer link 102. The gear teeth 98 operatively engage with gear teeth 104 
of an intermediate outer link 106. Links 102 and 106 are located again in 
an evenly spaced-apart manner and mounted on pivot pins 72 and 78 with the 
respective spacers 76 and 82 being located therebetween. The link 102 also 
includes gear teeth 108 with link 106 terminating in its outer end in gear 
teeth 110. Gear teeth 108 operatively engage with gear teeth 112 of a 
distal outer link 114. Gear teeth 110 operatively engage with gear teeth 
116 of a distal outer link 118. The distal outer links 114 and 118 are 
pivotally mounted on the pivot pins 80 and 86 and located in an evenly 
spaced-apart manner therebetween with again their spacers 84 and 88 
maintaining the spacing. 
The outer links 90, 102 and 114 are again mounted in an end-to-end 
relationship within a single plane. In a similar manner the outer links 
102,106, and 118 are mounted within a single plane in an end-to-end 
relationship. Distal link 114 terminates also in a series of gear teeth 
120 with distal link 118 terminating in a set of gear teeth 122. The gear 
teeth 120 and 122 are not being utilized within the embodiment of FIGS. 1 
to 4 and FIG. 6. However, if additional links are added, gear teeth are 
utilized such as is shown in FIG. 5 where gear teeth 122' of link 118" 
operatively engages with gear teeth 124 of a distal link 126. Link 64' is 
pivotally connected by pivot pin 128 and spacer 130 to the distal link 
126. It is the distal link 126 that is connected by the fastener 131 to 
the tool which is not shown in FIG. 5. 
Regarding the embodiment in FIG. 5 it is basically similar in the linkage 
arrangement to the embodiment of FIG. 1 to 4 and like numerals have been 
utilized to refer to like parts. However, as previously mentioned it is to 
be noted that the distal link 126 has been added which shows that the tool 
68 could be connected to either the outer series of links or the inner 
series of links. Also, it is to be understood that both this outer series 
of links and inner series of links can continue on for any desired number 
greater or less than what is shown in the drawings. Still further in FIG. 
5 it can be seen that the spacing between directly adjacent pivot pins 24' 
and 70' is greater than the spacing between pivot pins 70' and 72'. This 
is just to represent that the spacing between the pivot pins can vary as 
well as length of the links can vary. It is to be noted that within FIGS. 
1 to 4, the spacing between the pivot pins 24 and 70 is equal to the 
spacing between the pivot pins 70 and 72, and between the pivot pins 72 
and 78, and between the pivot pins 78 and 80, and between the pivot pins 
80 and 86. 
Mounted on both proximal links 20 and 22 by means of a pivot pin 132 is a 
pivot block 134. Block 134 is capable of freely pivoting relative to the 
proximal links 20 and 22. Threadably mounted within the block 134 is a 
threaded shaft 136. Threaded shaft 136 is rotatable by a motor 138. The 
motor 138 is operated electrically by electrical power being supplied 
through electrical conductor 140. The motor 138 is confined within a motor 
housing 142 which is fixedly mounted by mounting pins 144 on base 
stanchion 14. 
Rotatably mounted to the proximal link 20 and located between the proximal 
link 20 and the proximal link 22 is an idler gear 146. The idler gear 146 
is mounted by the pivot pin 148. In a similar manner an identical idler 
gear 150 is pivotally mounted by pivot pin 152 to the proximal link 22. 
Idler gear 146 is in continuous engagement with the gear teeth (not shown) 
of link 90 with idler gear 150 being in continuous engagement with gear 
teeth 96 of link 92. Idler gear 146 is in continuous engagement with the 
drive gear 154 with idler gear 150 being in continuous engagement with the 
drive gear 156. The drive gears 154 and 156 are fixedly mounted on pivot 
pin 18. Also mounted on pivot pin 18 is an arm 158. Arm 158 has mounted on 
the lower end thereof a pivot block 160. The pivot block 160 is freely 
pivotally mounted on the arm 158 by means of a pivot pin 162. Threadably 
engaged with the pivot block 160 is a threaded shaft 164. Shaft 164 is 
rotated by motor 166 which is electrically operated by electricity being 
supplied through a conductor 168. The housing 170 of the motor 166 is 
fixedly mounted by mounting pins 172 to base stanchion 16. 
Operation of the motor 138 will cause the proximal links 20 and 22 to pivot 
on the pivot shaft 18. This causes the proximal links to pivot relative to 
the links 36 and 40 which will cause the links 36 and 40 to assume a 
different angular position relative to the proximal links 20 and 22. The 
same is true between the links 36 and 40 to the respective links 48 and 52 
and links 58 and 64. The result is by operation of the motor 138, the arm 
mechanism shown in FIG. 1 can move from the solid line position to the 
dotted line position. 
Operation of the motor 166 all by itself will cause a similar movement to 
occur relative to the links 90, 92, 102, 106, 114, and 118 and also can 
cause the arm mechanism to move from the solid line position shown in FIG. 
1 to the dotted line position. However, by operating of both motors 138 
and 166 simultaneously, the movement from the solid line position in FIG. 
1 to the dotted line position can be accomplished much quicker. Also 
because there are two separate motors utilized the degree of control for 
short, fine movements can be achieved as opposed to using only a single 
motor. As is readily apparent in FIG. 1, the motors 138 and 166 can be 
operated to cause the arm mechanism to assume a straight line 
configuration which is also shown in dotted lines in FIG. 1. 
One difference of the embodiment shown in FIG. 5 is that it is intended to 
have only one motor to be connected to the link 22'. Link 92' has gear 
teeth 171 which connect with a gear 174. Gear 174 would be mounted on the 
base stanchion 12'. Proximal link 22' is pivotally mounted on the base 
stanchion 12' by means of a pivot pin 176. FIG. 5 is represents that a 
greater number of links could be utilized than what was shown in FIGS. 1 
to 4 and that also the tool 68, as was previously discussed, could be 
connected to either the inner series of links or the outer series of 
links. Also FIG. 5 is shown in the drawings in order to substantiate that 
only a single motor could be utilized as opposed to the two-motor 
configuration shown in FIGS. 1 to 4. Also in FIG. 5, it can be readily 
seen that the link 22' is of a different width than link 40' with link 52' 
being again of a different width than link 40'. Therefore, variation in 
the width of the links is certainly permitted. 
Referring particularly to FIG. 6 there is shown an arm mechanism similar to 
the arm mechanism in FIGS. 1 to 4. Arrow 178 is used to designate threaded 
shaft 136 with arrow 180 designating threaded shaft 164. The only real 
difference in the arm mechanism of FIG. 6 as opposed to FIGS. 1 to 4 is 
that the pivot pins 24", 70", 72", 78", 80", and 86" are not centrally 
mounted relative to the links 22", 92", 40", 106", 52", 118", and 64". 
These pivot pins are mounted directly adjacent one edge of these links. 
The reason for this is that when an arm mechanism is being designed to go 
only in a one hundred and eighty degree direction as opposed to a 
substantially three hundred and sixty degree direction as shown in FIGS. 1 
to 4, then by locating of the pivot pins adjacent a side edge of the links 
will increase the movement in that particular direction. In other words 
the arm mechanism of FIG. 6 will be able to move closer to the base 10 
than the arm mechanism of FIG. 1.