A device for exercising animals such as primates is described, which includes a cylindrical housing mounted for rotation about a horizontal axis of revolution and has a cylindrical treadway portion on which the animal treads while the drum is rotated by means of a motorized drive. The treadway portion of the drum includes an electrode structure with sectors being independently energizable by means of a commutator and source of potential so that an electrical shock station is created behind a running-in-place station on the moving treadway. In this manner, if the animal should fall behind its running-in-place station, it may be shocked by treading on the energized electrode structure. One end of the tread drum comprises a transparent wall for unobstructed viewing of the animal being exercised

Howard, W. H.

English

NASA Technical Reports Server

United States Patent [I91 11 11 4,088,094 
Howard 1451 May 9,1978 
TREAD DRUM FOR ANIMALS 
Inventor: 
Assignee: 
Wayne H. Howard, Menlo Park, 
calif. 
The United States of America u1 
represented by the MminWrator of 
the National Aeronautics and Space 
Admlnistntion, Washington, D.C. 
Appl. NO.: 672,223 
Filed: Mu.31,1976 
ht. CI.2 .............................................. AOlK 15/00 
us. CI. ...................................................... 119/29 
Field of Seucb ................ 119/29, 1, 15; 272/115 
Refmncea Cited 
U.S. PATENT DOCUMENTS 
2,663,282 12/1953 Ingle ...................................... 119/29 
3,057,328 10/1%2 Swartz ................................... 119/29 
Primav Examiner-Jay N. Eskovitz 
Attorney, Agent, or Firm-Darrell G. Brekke; John R. 
Manning 
B7I ABSTRACT 
A tread drum for animals, such as primates, includes a 
cylindrical housing mounted for rotation about a hori- 
zontal axis of revolution and having a cylindrical tread- 
way portion on which the animal treads while the drum 
is rotated by means of a motorized drive. The treadway 
portion of the drum includes an electrode structure 
incorporated therein, with sectors thereof being inde- 
pendently energizable by means of a commutator and 
source of potential so that an electrical shock station is 
created behind a running-in-place station on the moving 
treadway. In this manner, if the animal should fall be- 
hind its ruqing-in-place station, it may be shocked by 
treading on the energized electrode structure. One end 
of the tread drum comprises a transparent wall for un- 
obstructed viewing of the animal being exercised. 
9 claims, 7 Drawing Figures 
RUNNING IN 
PLACE 
STATION 
3r8 
https://ntrs.nasa.gov/search.jsp?R=19780019790 2020-03-20T13:37:41+00:00Z
U.S.Patent May 9, 1978 Sheet 1 of 2 4,4388,094 
F i g 2  Fig-5 
May 9, 1978 Sheet 2 of 2 4,088,094 
5 
Fig-6 
REVOLUT IO 
COUNTER 
SWITCH 
,48 
Fig-7 
1 
4,088,094 
TREAD DRUM FOR ANIMALS 
The invention described herein was made by an em- 
ployee of the United States Government and may be 5 
manufactured and used by or for the Government for 
governmental purposes without the payment of any 
royalties thereon or therefore. 
BACKGROUND OF THE INVENTION 
The present invention relates in general to tread- 
wheels for animals and more particularly to a tread 
drum particularly useful for primates and incorporating 
a selectively energizable electric shock station. 
DESCRIPTION OF THE PRIOR ART 
Heretofore, tread drums have been proposed for ex- 
ercising animals. In one prior art tread drum, as exem- 
plified by U.S. Pat. No. 3,057,328 issued Oct. 9, 1962, 
the treadway of the drum was formed by an electrode 20 
structure which could be selectively energized with an 
electrical potential for imparting an electrical shock to 
the animal running on the cylindrical treadway. The 
end walls of the drum were made of a transparent plas- 
tic for observation of the animal. The animal's reaction 25 
15 
to the electrical shock was observed through the trans- 
parent end walls. 
In this prior art device, the entire treadway was ener- 
gized with the electrical shock potential. Stationary 
brushes riding on slip rings on one of the ends of the 
drum were utilized for transmitting the shock potential 
to the electrodes of the treadway. While such an ar- 
rangement may be suitable for observing the reaction of 
mice and other animals to electrical shock, it is desirable 
for certain studies on the stress in primates and larger 
animals to provide a tread drum in which only a se- 
lected portion of the treadway can be energized with 
the potential to create an electrical shock station down 
track from a running-in-place station so that the animal 
under observation can be taught to run continuously in 
the running-in-place position at the speed of the tread- 
way. 
SUMMARY OF THE PRESENT INVENTION 
The principal object of the present invention is the 
provision of an improved thread drum for animals and 
more particularly to such a drum including the provi- 
sion of an electrical shock station disposed down track 
from a running-in-place station. 
In one feature of the present invention, the treadway 
of an animal tread drum includes an electrode structure 
for imparting an electrical shock to the animal, such 
electrode structure being selectively energizable only in 
a predetermined shock station region while the tread- 
way is in motion, whereby an electrical shock is im- 
parted to the animal when the animal falls behind its 
running-in-place station on the moving treadway. 
In another feature of the present invention, a commu- 
tator is employed for applying the electrical shock po- 
tential to the selectively energizable shock station of the 
moving treadway. 
In another feature of the present invention, a motor- 
ized drive is coupled to the tread drum for rotating the 
tread drum at a predetermined angular velocity. 
Other features and advantages of the present inven- 
tion become apparent upon perusal of the following 
specification taken in connection with the accompany- 
ing drawings wherein: 
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65 
2 
BRIEF DESCRIPTION OF DRAWINGS 
drum incorporating features of the present invention, 
FIG. 1 is a front perspective view of an animal tread 
FIG. 2 is a back perspective view of the tread drum 
FIG. 3 is an enlarged detail view of a portion of the 
structure of FIG. 1 delineated by line 3-3, 
FIG. 4 is a schematic line diagram of the tread drum 
of the present invention depicting its mode of operation, 
FIG. 5 is a schematic line diagram of the commutator 
employed for applying the electrical potential to the 
shock station in the tread drum of FIG. 4, 
FIG. 6 is a schematic diagram, in block diagram form, 
of the shock training electronics for the tread drum of 
the present invention, and 
FIG. 7 is a schematic block diagram of the drum 
rotation control for the tread drum of the present inven- 
tion. 
DESCRIPTION OF THE PREFERRED 
EMBODIMENTS 
Referring now to FIGS. 1 and 2, there is shown the 
tread drum 11 of the present invention. The tread drum 
11 includes a stand 12 having a pair of horizontally 
directed foot portions 13 which are interconnected by 
means of a generally vertically direct inverted U-shaped 
leg structure 14. The top of the inverted U-shaped leg 
structure 14 is centrally bored to receive a bearing as- 
sembly which in turn receives, in supportive rotational 
engagement, a horizontally directed axle 15 fixedly 
secured to a drum-shaped housing 16. The drum-shaped 
housing 16 includes a pair of axially spaced rings 17 and 
18 having a cylindrical stainless steel mesh 19 affixed 
therebetween to form a cylindrical treadway of the 
tread drum housing 16. 
Ring 17 is affixed to the axle 15 via the intermediary 
of a centrally disposed hub 21 and a plurality of radially 
directed spokes 22. The end of the drum 16, which 
includes the spokes 22, is closed off via the intermediary 
of a disk-shaped metallic end wall portion 23. The oppo- 
site or front end of the cylindrical drum-shaped housing 
16 is closed off by means of a transparent sheet of mate- 
rial such as a disk of plexiglass 24. A plurality of 
strengthening ribs 25 extend axially between the rings 
17 and 18 on the outside of the mesh treadway 19 at the 
ends of the spokes 22. A sliding access door 26 is pro- 
vided in the sheet metal closing wall 23 to permit in- 
gress and egress of animals to and from the drum 16. 
The drum 16 is rotationally driven by a motor 27 
carried on one of the foot members 13 of the stand 12. 
The output shaft of the motor is coupled to the axle 15 
of the drum 16 via the intermediary of a plurality of 
pulleys and drive belts 28 and 29 respectively. Four 
wheels 31 are affued to the horizontal feet 13 of the 
stand 12 to facilitate movement of the tread drum 11. 
Referring now to FIG. 3, the treadway 19 includes an 
electrode structure incorporated therein for imparting 
an electrical shock to the animal treading on the tread- 
way 19. More particularly, 14 to 16 guage bare bus wire 
32 is carried from the mesh 19 via the intermediary of 
longitudinally split tubular insulator members 33, as of 
rubber. The bare wire 32 is tied around each of the 
insulators 33. The circumferential spacing of the axially 
directed bus wire 32 is arranged so that a foot of the 
animal will contact one of the bare shock electrode 
wires 32 and an adjacent bare wire of the mesh 19 which 
is operated at ground potential. In a typical example for 
O ~ F I G .  1, 
4,088,094 
3 4 
a primate tread drum 16, the stainless steel mesh 19 is a the electric shock sector is relocated. More particularly, 
one-inch mesh and every other row of mesh elements when the drum is turned clockwise, the shock station 37 
includes an electrode 32. extends from 90 to 135 degrees. When the drum is 
The cylindrical treadway 19 is divided into a plurality turned counterclockwise the shock station 37 is moved 
of circumferentidy spaced sectors, such as eight sec- 5 to the 225O-270" segment. Four fmed-position brushes 
tors each of 45" peripheral extent and the electrode 30,35,40 and 50 can be individually selected by selec- 
wires 32 in each sector are connected together for sepa- tion switch u) to energize one brush at a time. After a 
ratelY energizing each sector. The eight Wires COUPb3 test is conducted, the primate sometimes remains in the 
to the separate eight sectors are then brought out to a top of the drum and refuses to leave the drum. It is 
commutator Structure 34 as Shown in FIG. 5. The corn- 10 dangerous for an animal handler to reach through door 
mutator 34 is carried at the hub 21 and is fmedly secured 26 and try to forcibly remove the Brushes 40 
to rotate with the tread drum 16. A brush assembly 35 and 50 enable the upper regions of the drum 16 to be- 
is disposed adjacent the commutator sectors 36 of the come shock stations 37. 
commutator 34 and in axially spaced relation therefrom Referring now to FIG. 7, there is shown a block 
for riding on a circular track comprising a circular array 15 diagram of the drum roation control circuitry. More 
particularly, a rheostat and reverse polarity switch as- of individual commutator sectors 36. 
35 is conductively 'On- sembly 47 operated by the operator controls the flow of 
nected to a source of electrical potential sufficient to power to the drum motor 27 for controlling the angular 
provide an electrical shock to the animal under observa- velocity of the tread drum 16 as driven from the motor 
tion. The stationary brush 35 serves to sequentially 20 27 via the pulley and belt drive 28 and 29. The velocity 
energize the respective sectors of the electrode wire 32 of the tread drum 16 is reused and the reused output fed when each Of the sectors 36 rotates into the to a speedometer 48 to allow the operator to control the 
angular velocity of the tread drum by adjusting the position of the brush 35. 
embodiment of the present invention wherein the brush 25 ometer In addition, a total count of the revolution of 35 is positioned relative to the commutator sectors 36 so the tread drum 16 is obtained by of a revolution that only the particular sector of the electrode structure counting switch 49 which is coupled to the tread drum which corresponds to an electrical shock station region 
37 will be energized. The electrical shock station 37 is for deriving an output for each revolution. The output 
preferably located down track from a running-in-place 3o of the switch is fed to a revolution counter 51 for dis- 
station 38 so that as the animal tires or begins to fall playing the total revolutions to the operator. 
behind the running-in-place station 38, the operator may Of the tread drum l1 Of the present 
actuate the shock station 37 to impart an elec- invention over that of the aforecited U.S. Pat. No. 
trical shock to the animal, thereby causing the animal 3,057,328 is that O d Y  a selected portion, namely, the 
speed up its movements and return to the running-in- 35 electric shock station 37 of the treadway 19 is energized 
associated with activation of the electrical shock station shocked Only when the animal falls behind its running- 
38 so that the animal is conditioned audibly to return to in-place station. The advantage of this feature is that it 
the running-in-place station merely by activation of the greatly reduces the training time required to train the 
buzzer. 40 animal to remain in the running-in-place station irre- 
As an alternative to the sector commutator having a SPective Of the angular velocity of the treadway. 
relatively few number of sectors 36, as shown in FIG. 5, 
the commutator 34 may comprise a circular array of the means for 
ends of the individual electrode wires 32. The brush 35 rotation about an axis Of reVOlUtiOn and dimensioned to 
would be increased in circumferential extent SO that 45 contain therewithin an animal to be exercised, said 
electrical contact is made from the brush 35 to fth of the housing means having a Closed treadway portion on 
number of exposed conductors 32 so as to energize an Which the animal is to tread while said housing means 
equivalent sector of the treadway within the electrical and said treadway portion rotate about said axis of revo- 
shock station 37. The position of the stationary brush 35 lution; 
would determine the position of the shock station 37. said treadway having a Plurality of electrodes capable 
Referring now to FIG. 6, there is shown a block of applying an electrical shock to an animal tread- 
diagram of the shock training electronics utilized with ing thereon when said electrodes are energized; 
the tread drum 11 of FIGS. 1-5. More particularly, the means for enabling, at a selected time, the selective 
operator, when the animal falls behind the running-in- energization of that portion of said electrodes that 
place station 38, actuatues a switch 41 which energizes 55 are located in a shock station region, said shock 
a buzzer 42. After a short delay provided by delay 42, station region being immobile and behind a run- 
the output of the switch energizes a source of shocking ning-in-place region of said treadway whereby said 
potential 44 which is thence fed through a current rim- animal can be shocked if it should fall behind said 
iter 45 and selector switch 20 via cable to the commuta- running-in-place region of said treadway. 
tor brush 35 and thence via the commutator 34 to the 60 2. The apparatus of claim 1 including motor means 
selector of electrode wires 32 which is disposed within coupled to said housing means for rotating said housing 
the electrical shock station 37. means. 
During experiments with a primate in the tread drum 3. The apparatus of claim 1 wherein said means for 
11, the primate is normally visually monitored with a enabling selective energization includes commutator 
TV camera. Sometimes the left profile is desired and 65 means for applying an energizing electrical potential 
sometimes the right profile is desired (depending on derived from a stationary source of electrical potential 
location of body sensors, etc.). The drum motor 27 is to said electrodes located in said shock station region of 
reversible. When the direction of rotation is changed, said rotatable treadway. 
The brush 
Referring to 4y there is shown a preferred rheostat 47 in accordance with the reading ofthe speed- 
The 
place station 38. It is also desirable to have a buzzer with the electrical potential so that the animal 
What is claimed is: 
In a tread drum for animals: 
50 
4,088,094 
5 6 
4. The apparatus of claim 1 wherein at least one wall 7. The apparatus of claim 6 including door means 
of said housing means it is made of a transparent mate- provided in one of said disk-shaped walls for providing 
rial for generally unobstructed viewing of the animal means of ingress and egress to and from said housing 
means for the animal. while the tread drum is in use. 
8. The apparatus of claim 2 including means for con- 5. The apparatus of claim 1 wherein said housing trolling the angular velocity of said housing means as means includes a pair of disk-shaped axially spaced driven by said motor means, 
walls enclosed by a circular wall portion, and wherein 9. The apparatus of claim wherein said for 
said axis of revolution of said housing means is coaxial enabling selective ener&tion includes for 
with the axis Of reVOlUtiOn Of said Circdar Wall portion. 10 sounding an alarm audible to said animal a pedeter- 
6. The ~PParatus of Claim 5 wherein said treadway mined period before said shock station region elec- 
portion includes said circular wall portion of said how- trodes are energized. 
ing means. 
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Tread drum for animals

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