U.S. patent number 3,662,647 [Application Number 05/090,979] was granted by the patent office on 1972-05-16 for quick emplacement gun carriage mechanism.
This patent grant is currently assigned to The United States of America as represented by the Secretary of the Army. Invention is credited to Leonard L. King.
United States Patent |
3,662,647 |
King |
May 16, 1972 |
QUICK EMPLACEMENT GUN CARRIAGE MECHANISM
Abstract
In order to convert a wheeled gun carriage between fixed
emplacement ther and a mobile towing position, each wheel is
mounted to one end of a support arm which is, in turn, angularly
pivoted to the side of the gun-support frame in geared connection
with a rotatable shaft extending transversely through the frame in
position to be rotated by movement of the vehicle utilized to tow
the carriage whereby back-up movement of the towing vehicle
actuates the support arms to tilt the wheels outwardly of the frame
to effect the lowering thereof into fixed emplacement on the ground
and whereby subsequent forward movement of the towing vehicle
actuates the support arms to return the wheels to the vertical
position required to permit the normal towing of the carriage.
Inventors: |
King; Leonard L. (Rock Island,
IL) |
Assignee: |
The United States of America as
represented by the Secretary of the Army (N/A)
|
Family
ID: |
22225205 |
Appl.
No.: |
05/090,979 |
Filed: |
November 19, 1970 |
Current U.S.
Class: |
89/40.11 |
Current CPC
Class: |
F41A
23/28 (20130101) |
Current International
Class: |
F41A
23/28 (20060101); F41A 23/00 (20060101); F41f
023/20 () |
Field of
Search: |
;89/4R,4A,4J |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Bentley; Stephen C.
Claims
I claim:
1. In a mobile gun carriage having a frame normally supported
between a pair of wheels in position to permit the carriage to be
towed by a separate vehicle, the combination of,
a rotatable shaft transversely seated in the frame between the
opposite sides thereof,
a pair of support arms, each having a wheel mounted at one end
thereof and pivotally attached at the other end thereof to the side
of the frame adjacent the end of said rotatable shaft,
a tow bar slidably mounted in the frame for forward and rearward
longitudinal displacement,
first gear means for converting longitudinal displacement of said
tow bar to rotation of said shaft, and
second gear means for converting rotation of said shaft to pivotal
movement of said support arms about an axis parallel to the
longitudinal axis of the frame whereby the wheels are
simultaneously tilted in opposite directions to lower or raise the
frame into and out of fixed engagement with the ground in
accordance with the direction in which said tow bar is
displaced.
2. The mobile gun carriage of claim 1 wherein said support arms are
pivotally attached to the sides of the frame at an angle to the
horizontal with the ends to which the wheels are mounted being in a
lower plane than the opposite ends thereof whereby the tilting of
the wheels is accomplished with a progressive outward displacement
thereof relative to the sides of the frame which produces a
corresponding increase in the rapidity with which the latter is
lowered into contact with the ground.
3. The mobile gun carriage of claim 1 including torsion bar means
in each of said support arms arranged to be preloaded by the weight
of the frame and the gun thereon to provide resilient suspension
therefor during the towing travel thereof.
4. The mobile gun carriage of claim 1 wherein said first gear means
comprises,
a rack gear secured to the end of said tow bar within the
frame,
a pinion gear rotatably mounted in the frame for meshing engagement
with said rack gear,
a worm gear mounted in the frame for synchronous rotation with said
pinion gear, and
a worm wheel fixed to said rotatable shaft in meshing engagement
with said worm gear.
5. The mobile gun carriage of claim 1 wherein said second gear
means comprises,
a bevel gear secured to said rotatable shaft at each end
thereof,
a pivot member projecting outwardly from each of said support arms
for rotatable engagement in the side of the frame at a location
adjacent said bevel gear, and
a bevel gear segment secured to said pivot member for meshing
engagement with said bevel gear.
6. A mobile gun carriage convertible to a fixed firing position
comprising,
a frame having a rotatable shaft extending transversely between the
opposite sides thereof,
a pair of support arms respectively pivoted at one end thereof to
opposite sides of said frame adjacent the ends of said shaft,
a wheel mounted to each of said support arms at the other end
thereof,
a tow bar slidably disposed in said frame for longitudinal
displacement therein,
gear means for converting longitudinal displacement of said tow bar
to rotation of said shaft,
a bevel gear secured to each end of said rotatable shaft, and
a bevel gear segment secured to each of said pivoted ends of said
support arms in respective meshing engagement with said bevel gears
on said shaft for converting the rotation thereof into pivotal
movement of said arms about an axis parallel to the longitudinal
axis of said frame whereby said wheels are tilted outwardly
relative to the sides of said frame to permit the latter to be
correspondingly lowered into contact with the ground in response to
the weight of said frame and the gun thereon.
7. The mobile gun carriage of claim 6 including preloaded torsion
bar means in said support arms for urging the latter to pivot about
an axis perpendicular to the longitudinal axis of said frame during
the concurrent pivotal movement imparted to said arms by said bevel
gears at the ends of said shaft whereby the tilting of said wheels
is accelerated when the vertical component of the forces imparted
thereto falls below the preload of said torsion bars thereby to
minimize the tendency to skid under the external forces applied to
the carriage during the displacement of said tow bar.
8. The mobile gun carriage of claim 7 wherein said torsion bar
means comprises,
a torsion bar pinned at one end thereof in each of said support
arms,
a bevel gear segment secured to the other end of said torsion bar,
and
a bevel gear fixedly secured within said support arm in meshing
engagement with said bevel gear segment whereby said torsion bar is
normally preloaded to the extent required to balance the weight of
said frame and gun thereon.
9. A mobile gun carriage convertible between a fixed firing
position and a rolling travel position comprising,
a frame having a rotatable shaft extending transversely between the
opposite sides thereof,
a pair of support arms each having a wheel at one end thereof,
means for pivotally connecting the opposite ends of said support
arms to the respective opposite sides of said frame adjacent the
ends of said rotatable shaft therein,
a tow bar slidably disposed in one end of said frame for
longitudinal displacement in either direction responsive to
external forces thereon,
first gear means in said frame for converting longitudinal
displacement of said tow bar into corresponding rotation of said
transverse shaft,
second gear means between the ends of said shaft and said pivotal
connecting means in said support arms for converting rotation of
said shaft to pivotal movement of said support arms about an axis
parallel to the longitudinal axis of said frame whereby said wheels
are simultaneously tilted in opposite directions to permit the
lowering and raising of said frame into and out of fixed contact
with the ground, and
preloaded torsion bar means for pivoting said support arms at right
angles to the pivotal movement imparted thereto by said second gear
means whereby said wheels are positively steered in the direction
of the tilting thereof to facilitate the raising and lowering of
the frame and the gun thereon.
10. The mobile gun carriage of claim 9 including a plurality of
equilibrator springs adjustably seated in said frame, and
a follower at the end of said tow bar within said frame operatively
connected with said springs for compressing said springs during the
lowering of said frame into contact with the ground thereby to
provide sufficient energy for raising said frame to the travel
position thereof in cooperation with the external forces being
applied to said tow bar.
11. The combination defined in claim 9 including,
a detent releasably engageable with said tow bar to prevent
displacement thereof,
means on said detent for facilitating manual disengagement thereof
from said tow bar, and
spring means for biasing said detent normally into engagement with
said tow bar during the longitudinal displacement imparted thereto
for returning the carriage to the rolling travel position
thereof.
12. The mobile gun carriage of claim 9 wherein each of said pivotal
connecting means includes
a pivot member,
a cylindrical portion of said pivot member being rotatably seated
in the side of said frame in parallelism with the longitudinal axis
thereof in position to be rotated by said second gear means,
a flange portion projecting outwardly from said cylindrical portion
and parallel thereto to serve as a bearing surface for said support
arm during the pivotal movement imparted thereto by said torsion
bar means, and
a rod portion extending outwardly from the center of said flange
portion into rotatable engagement with said support arm to serve as
an axis for the pivotal movement thereof at right angles to the
direction of the pivotal movement imparted thereto by said second
gear means.
13. The mobile gun carriage of claim 9 wherein said torsion bar
means comprises,
a torsion bar pinned at one end thereof within said support arm
adjacent said wheel,
third gear means in said support arm for rotating said torsion bar
in response to the pivotal movement of said support arm about an
axis at right angles to the pivotal movement imparted thereto by
said second gear means, and
stop means for halting the rotation of said torsion bar in one
direction to limit the unwinding thereof after said frame has been
lowered into contact with the ground and in the opposite direction
to limit the additional loading imparted thereto during the rolling
travel of the carriage in the event of relative motion between said
frame and said support arms.
14. The mobile gun carriage of claim 13 wherein said means for
pivotally connecting said support arms to the sides of said frame
includes an outwardly projecting rod portion extending through said
support arm in rotatable engagement therewith and wherein said
third gear means in each of said support arms comprises,
a bevel gear secured to said rod portion, and
a bevel gear segment secured to the free end of said torsion bar in
meshing engagement with said bevel gear whereby pivotal movement of
said support arm about said rod portion actuates said gear segment
to rotate said torsion bar accordingly.
15. The mobile gun carriage of claim 14 including stop means for
halting the rotation of said torsion bar comprising,
a C-shaped insert fixedly secured within said support arm to
straddle said bevel gear segment, and
a stop surface on each end of said insert disposed in the path of
movement of said bevel gear segment.
Description
BACKGROUND OF THE INVENTION
This invention relates to the emplacement of a mobile gun carriage
and is more particularly directed to means for rapidly converting
the mobile support for the carriage to a fixed ground support
capable of withstanding the recoil forces imparted thereto during
the firing of the gun.
In gun carriages wherein the frame utilized to support the gun is
mounted between a pair of wheels and consequently must be in a
fixed position relative to the ground while the gun is being fired
in order to insure the desired accuracy, the necessity for
elevating the frame to lift the wheels off the ground and
substitute a fixed support base therefor is customarily
accomplished by one or more jacks. The dependance on such
accessories not only complicates the emplacement of the gun but,
more importantly, also detracts from the rapidity with which it can
be relocated in the event of enemy action. Furthermore, where the
combined weight of the gun and support frame therefor cannot be
handled by manually operated jacks, the necessary power is usually
provided by relatively bulky generators which require more
elaborate maintenance procedures than those which can ordinarily be
followed under combat conditions.
Accordingly, it is an object of this invention to provide a simple,
rugged, and reliable mobile gun carriage which can be readily
converted between a mobile towing position and a fixed firing
position far more rapidly than has heretofore been possible.
It is also an object of this invention to provide a relatively
large caliber gun with a wheeled carriage which can be rapidly
emplaced in a fixed position on the ground without the need for
manual or power-operated jacks.
Another object of this invention is to provide a wheeled gun
carriage, as aforesaid, wherein the required rapid conversion
between mobile and fixed support positions can be readily
accomplished by simultaneously tilting both wheels outwardly or
inwardly relative to the sides of the frame.
An additional object of the present invention is the provision of a
system for emplacing a wheeled gun carriage wherein the weight of
the gun and the support frame therefor provides the energy required
to tilt the wheels in the direction in which the frame will be
lowered into contact with the ground.
Still another object of this invention is to provide a gun
carriage, as aforesaid, which can be equilibrated so that the
lowering of the gun-support frame into contact with the ground will
provide energy which can be stored to participate in the subsequent
raising of the frame to the mobile support position.
A further object of the present invention lies in the provision of
a mechanical system for fixedly emplacing a mobile gun carriage
wherein the lowering and raising movement of the gun supporting
frame can be initiated either by the transporter vehicle utilized
to tow the carriage or by the personnel assigned to operate the
gun.
An important object of this invention is to provide a gun
emplacement system, as aforesaid, wherein the rate of change in the
angular relationship of the wheels relative to the ground during
the tilting movement thereof can be resiliently varied to enhance
the lowering and raising of the gun-support frame.
SUMMARY OF THE INVENTION
It has been found that the foregoing objects can best be attained
if the tow bar to which the transporter vehicle attaches is
slidably disposed in the rear end of the carriage frame in geared
connection with a transversely extending rotatable shaft. Each end
of the shaft is, in turn, geared to one end of a longitudinal
support arm which extends along the side of the frame at at acute
angle relative to the ground to terminate in a wheel at the other
end thereof. In addition, support arms are respectively attached to
opposite sides of the frame so as to pivot about an axis at right
angles to the longitudinal axis of the rotatable shaft. Thus,
rotation of the shaft in either direction will tilt both wheels
about the areas of contact thereof with the ground in opposite
directions relative to the sides of the frame. Each support arm
also houses a torsion bar in geared connection with the pivot
member to which the support arm is mounted. These torsion bars are
arranged to be actuated during the lowering and raising of the
frame to vary the rate of change in the angular relationship
between the wheels and the ground during a portion of the tilting
movement thereof. The tow bar is arranged to be releasable locked
to the frame and the end extending therein is provided with a
follower device for compressing one or more equilibrator springs
seated within the interior of the frame.
Thus, once the tow bar is unlocked and pushed inwardly relative to
the frame, the interaction of the gears therein will begin to pivot
the support arms in the direction required to tilt the wheels
outwardly of the sides of the frame whereupon the combined weight
of the gun and the support frame will produce the energy required
to continue such tilting. When the energy stored in the torsion
bars exceeds the vertical component of the load on the wheels, such
bars unwind to accelerate the tilting of the wheels and thereby
reduce the time required to bring the support pads on the underside
of the frame into contact with the ground to complete the fixed
emplacement of the carriage. When the frame is to be restored to a
mobile towing position, the tow bar is pulled outwardly thereof,
either manually or by the transporter vehicle utilized to provide
the towing, thereby actuating the gearing to pivot the support arms
in the direction required to tilt the wheels inwardly relative to
the sides of the frame. During the initial tilting of the wheels,
the torsion bars are rewound to resiliently support the weight of
the carriage. The continued movement of the transporter vehicle and
the action of the equilibrator springs, which were previously
compressed during the lowering of the frame, provide the energy
required to continue the tilting of the wheels until the frame is
fully raised to the towing position thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
The exact nature of the invention as well as other objects and
advantages thereof will be readily apparent from consideration of
the following specification relating to the annexed drawings
wherein:
FIG. 1 is a perspective view of the gun carriage with the wheels in
the upright vertical position required to permit towing by a
separate vehicle;
FIG. 2 is an enlarged top plan view of the major portion of the
gun-support frame partially broken away to show the structural
details of the equilibrator springs and the relationship between
the tow bar and the rotatable shaft;
FIG. 3 is a sectional view taken along line 3--3 in FIG. 2 to show
the geared connection between the tow bar and the rotatable shaft
which extends transversely through the frame;
FIG. 4 is a sectional view taken along line 4--4 in FIG. 2 to show
the interior of one of the support arms and the angle at which it
is attached to the side of the frame;
FIG. 5 is a sectional view taken along line 5--5 in FIG. 4 to show
the gear structure which serves to unload and load the torsion bar
in the support arm during the lowering and raising of the frame,
the end of the support arm being shown in full for ease in
illustration;
FIG. 6 is a sectional view taken along line 6--6 in FIG. 4 to show
the details of the connection between the support arm and the
adjacent side of the frame;
FIG. 7 is a perspective view similar to that of FIG. 1 but showing
the carriage with the wheels tilted to the position required to
provide the fixed emplacement thereof on the ground;
FIG. 8 is a fragmentary sectional view through the enlarged end of
the support arm similar to that of FIG. 5 but showing the
relationship between the gear segment on the torsion bar and the
C-shaped stop when the wheels have been fully tilted to provide the
fixed emplacement shown in FIG. 7; and
FIG. 9 is a perspective view of the pivot member utilized to
connect the support arm to the side of the frame.
DESCRIPTION OF A PREFERRED EMBODIMENT
As shown in FIG. 1 of the drawings wherein similar reference
characters have been employed to designate corresponding parts
throughout, the gun carriage to which the present invention is
applicable essentially comprises a generally triangular frame 12 of
isoceles configuration with a base leg 14 of greater structural
rigidity than the isoceles legs. The ability of frame 12 to support
a gun (not shown) is additionally strengthened by an integral
central strut 16 extending between the apex of the isoceles legs
and the base leg 14. Hereinafter, references to directions are to
be construed in accordance with the orientation of the gun which is
mounted on frame 12 so that the muzzle or forward end thereof
extends beyond the apex of the isoceles legs. Thus, base leg 14 is
to be considered as located "rearwardly" of the apex of the
isoceles legs. A generally rectangular housing 18 extends
rearwardly from base leg 14 to axial alignment with strut 16 to
slidably receive a tow bar 20 terminating in a ring shaped end 22
arranged to be engaged by the pintle on a transporter vehicle (not
shown). In order to lock tow bar 20 against movement relative to
housing 18 during the towing of the carriage, a hollow stud 24
(FIG. 3) is threadably inserted in housing 18 in position to seat a
locking pin 26 and a spring 28 in abutment therewith for biasing
one end of pin 26 into releasable engagement with a mating recess
30 in the periphery of tow bar 20. A pull ring 32 at the opposite
end of locking pin 26 enables the latter to be manually disengaged
from tow bar 20 once the towing movement of the carriage has been
halted.
Extending rearwardly and outwardly from the ends of base leg 14 is
a trapezoidal subframe 36 connected to opposite sides of housing
18. At each end of subframe 36 and the forward apex of frame 12 is
a vertically adjustable support pad 38. In the mobile position of
the carriage, frame 12 is supported between a pair of wheels 40
attached to longitudinally extending support arms 42 respectively
geared to the ends of base leg 14 in a manner to be described
hereinafter. Wheels 40 are preferably provided with conventional
rubber tires 43 and are rotatably mounted on axles 44 (FIG. 2)
extending outwardly from the respective sides of support arms 42
adjacent the forward ends thereof. The diameter of wheels 40 is
such that frame 12 is supported thereby in a travel position at a
height which will prevent support pads 38 from contacting the
ground regardless of the unevenness of the terrain over which the
gun and carriage are being towed.
A longitudinal rack gear 46 is suitably pinned to the end of tow
bar 20 within housing 18, as indicated at 48 in FIGS. 2 and 3, and
extends into meshing engagement with a pinion gear 50 fixedly
secured to one end of a vertical shaft 52 which is, in turn,
rotatably mounted within base leg 14 in the area intersected by
housing 18. Shaft 52 also carries a worm gear 54 located above
pinion gear 50 in meshing engagement with a worm wheel 56 fixedly
mounted on an elongated rotatable shaft 58 extending through base
leg 14 from one end thereof to the other.
The opposite ends of base leg 14 are rectangularly recessed, as
indicated at 60 in FIG. 2, to provide space for a miter bevel gear
segment 62 fastened to the end of shaft 58 in meshing engagement
with a corresponding miter bevel gear segment 64 pinned, as at 65,
to an end of a cylindrical sleeve 66. The latter is, in turn,
mounted on a transverse pin 68 rotatably seated in the sidewalls of
recess 60. Sleeve 66 is also provided with a flange 70 extending
integrally outward from the exterior periphery thereof in the
direction of the open end of recess 60 to serve as a bearing
surface for the end face of a hub 72 protruding from the side of
support arm 42 at the end thereof opposite that on which wheel 40
is mounted.
As indicated at 74, the end of support arm 42 from which hub 72
projects is dimensionally enlarged and is provided with a
substantially rectangular opening 76 therein in communication with
a central bore 78 therethrough. Extending centrally outward from
flange 70 is a rod 80 which passes through hub 72 and rectangular
opening 76 into rotatable engagement with the sidewall of the
latter. Hub 72 is retained in bearing contact with flange 70 by
bevel gear 82 pinned to rod 80 in abutment with the interior wall
surface of opening 76 and in meshing engagement with a bevel gear
segment 84 which is, in turn, pinned, as at 86, to one end of a
torsion bar 88 extending through support arm 42. Gear 82 is formed
with a hollow cylindrical body 90 which fits into hub 72 over rod
80 and is fastened to the latter by a pin 92 which can be readily
inserted into place through suitable axially aligned holes 94 in
the walls of hub 72, as best shown in FIG. 5. Thus, support arms 42
are respectively attached to the opposite ends of base leg 14 for
pivotal movement about an axis parallel to the longitudinal axis of
frame 12 and for concurrent pivotal movement in a vertical plane
about an axis at right angles to the longitudinal axis of base leg
14.
The end of torsion bar 88 opposite the geared end thereof is
initially pinned to support arm 42 at 96 at a time when the
carriage has been lifted sufficiently to raise wheels 40 off the
ground. In this position, the inclination of support arm 42
relative to the horizontal is halted by the contact between the
upper side of the gear tooth portion of segment 84 and a
substantially C-shaped insert 98 fastened within rectangular
opening 76, as by screws 100. The spaced ends of insert 98
terminate in oppositely facing angular stop surfaces 102 and 103
which straddle the gear tooth portion of segment 84. Thus, when
gear segments 84 are in contact with upper stop surfaces 103,
support arms 42 are inclined at an angle to the horizontal which
does not impart any load to torsion bars 88. However, when wheels
40 are lowered into contact with the ground upon the removal of the
lifting force imparted to the carriage, the weight of frame 12 plus
the gun thereon will pivot support arms 42 about rods 80 thereby
driving gear segments 84 to impart twisting movement to torsion
bars 88 until the opposing forces are balanced. At this point, the
gear tooth portion of segment 84 is positioned substantially midway
of stop surfaces 102 and 103 on insert 98, as best shown in FIG. 5,
and support arms 42 are inclined at a lesser angle to the
horizontal which, in the support of a 4,000-lb. load, has been
found to be about 18.degree..
As shown in FIGS. 2 and 3, rack gear 46 extends below and beyond
shaft 58 into fixed engagement with a follower 104 to the opposite
side of which are secured the stem portions 106 of a pair of
horizontally spaced pistons 108. The interior of a portion of strut
16 is hollowed out, as indicated at 110, to accommodate follower
104 and piston stems 106 while the remainder of strut 16 is
provided with a pair of parallel longitudinal holes 112 laterally
spaced to slidably receive the head portions 114 of pistons 108.
Each hole 112 seats an equilibrator spring 116 between piston head
114 and a plug 118 which is releasably retained in one of a series
of detent openings 120 by means of which springs 116 may be
adjusted to provide the degree of bias required to raise frame 12
and the gun thereon to the towing position thereof.
In order to emplace the gun carriage, the transporter vehicle is
brought to a halt and locking pin 26 is manually lifted to
disengage from tow bar 20 and permit the latter to be pushed into
housing 18 in response to back-up movement of the transport
vehicle. This movement of tow bar 20 actuates rack gear 46 to
initiate rotation of shaft 58 thereby operating miter gear segments
62 and 64 to pivot support arms 42 about pin 68 in a clockwise
direction as viewed when looking forwardly from the rear of the
carriage. As a result, wheels 40 begin to tilt out of the vertical
support position with the portions thereof in rolling contact with
the ground moving outwardly away from frame 12 while the
diametrically opposite portions of wheels 40 are being moved
inwardly thereby causing frame 12 to be lowered toward the ground.
During this tilting movement of wheels 40, the preloaded torsion
bars 88 act on support arms 42 to force wheels 40 downwardly
against the ground to impart a steering action thereto outwardly of
frame 12. Since the tilting of wheels 40 and the lowering of frame
12 are mutually interdependent, such steering action serves to
promote the rapidity with which frame 12 and the gun thereon can be
lowered during the rolling travel imparted to the carriage by the
back-up movement of the transporter vehicle. Once the tilting of
wheels 40 has been initiated, the weight of the gun and support
frame 12 plays a dominant role in providing the energy required to
continue such tilting. In view of the angle to the horizontal at
which support arms 42 are attached to the ends of base leg 14 of
frame 12, the outward inclination of wheels 40 during the tilting
thereof is progressively increased to improve the rapidity with
which frame 12 is lowered into contact with the ground. Moreover,
as wheels 40 are being tilted, the contact thereof with the ground
is progressively shifted from the tread portion of the tires to the
crown portion thereof thereby producing a corresponding decrease in
the surface area in contact with the ground. When the vertical
component of the load being carried by wheels 40 falls below the
force produced by the preload on torsion bars 88, support arms 42
are pivoted about rods 80 to increase the 18.degree. angle thereof
relative to the horizontal thereby accelerating the final portion
of the tilting movement of wheels to minimize the scuffing and
skidding of tires 43 that would otherwise occur during this period
of minimum area contact with the ground. As support pads 38 come
into contact with the ground to support the weight of the carriage,
bevel gear segments 84 contact stop surfaces 103 on inserts 98, as
shown in FIG. 8, to complete the unwinding of torsion bars 88. At
this point, the crown portions of the tires on wheels 40 are still
in contact with the ground. The carriage will be properly emplaced
for firing as soon as support pads 38 contact the ground and take
the place of wheels 40 in supporting the weight of the gun and
frame 12.
In order to return the carriage to the mobile support position
thereof, the transporter vehicle is operated to pull on tow bar 20.
The resulting displacement of rack gear 46 actuates gears 50, 54
and 56 to rotate shaft 58 which, in turn, actuates gear segments 62
and 64 to initiate the pivoting of support arms 42 about pin 68 in
a counterclockwise direction, looking forwardly from the rear of
the carriage. Since wheels 40 were left in contact with the ground
at the conclusion of the lowering of the carriage, the pivotal
movement of support arms 42 about pin 68 immediately begins to tilt
wheels 40 and raise frame 12 off the ground thereby minimizing the
period during which support pads 38 will be dragged along the
ground by the pull imparted to the carriage by the transporter
vehicle. As support pads 38 are being lifted off the ground and the
weight of frame 12 is being shifted onto wheels 40, support arms 42
are pivoted about rods 80 to return to the previous inclination
thereof relative to the horizontal thereby actuating gear segments
84 to rewind torsion bars 88 to the extent required to balance the
weight of the gun and frame 12. During the subsequent raising of
frame 12, equilibrator springs 116, which were compressed during
the lowering of frame 12, supplement the pull of the transporter
vehicle on tow bar 20 to actuate the various gears and other
components involved in tilting wheels 40.
However, if for some reason the transporter vehicle is not
available, the energy provided by springs 116 is sufficient to
complete the raising of the gun and frame 12 once the locking
relationship between worm gear 54 and wheel 56 has been broken by
actuation of rack gear 46 in response to a manual pull on tow bar
20. In the event such manual actuation is to be utilized, springs
116 are preferably preloaded by positioning plugs 118 in the
particular detent opening 120 which will provide the energy
required to raise frame 12 to the desired height. Once wheels 40
are fully returned to the upright position required for mobile
support of frame 12, tow bar 20 will reach the position in which
locking pin 26 is again in alignment with recess 30 and will
automatically engage therewith under the bias of spring 28.
Inasmuch as the return of support arms 42 to the normal 18.degree.
inclination required to balance frame 12 and the gun thereon leaves
gear segment 84 midway of stop surfaces 102 and 103, as best shown
in FIG. 5, torsion bars 88 are utilized as the suspension system
for frame 12 and are free to absorb any additional load which may
be imparted thereto by the vertical movements encountered during
the travel thereof over rough and irregular terrain. Stop surface
102 serves to limit the twisting of torsion bars 88 and prevent
damage thereto from any overstress during the towing travel of the
carriage.
Thus, there is here provided a mobile gun carriage which can be
quickly emplaced in a fixed firing position and returned with even
greater rapidity to a mobile towing position. In fact, unlike
conventional gun carriages, the present invention permits the
towing travel thereof to be initiated while the frame is still
emplaced on the ground. This is extremely important in the event of
surprise enemy action which may require immediate relocation of the
gun to another firing site. This desirable rapid conversion of the
carriage between an emplaced firing position and a mobile towing
position is made possible by the unusual equilibrator spring
arrangement which permits the weight of the gun and the support
frame therefor to participate in the lowering of the frame to the
ground and to provide the major portion of the energy required to
raise the frame to the mobile position thereof. Furthermore, the
ability to lower and raise the carriage without the need for
separate accessory equipment or additional manpower is a highly
desirable improvement which will minimize the logistic problems
normally encountered under combat conditions. It is also noted that
the torsion bar arrangement described herein provides a highly
satisfactory suspension system whose operation does not interfere
with the required tilting of the wheels.
Although the present invention is explained in accordance with the
preferred embodiment shown and described herein, it will also
become obvious to persons skilled in the art that other forms
thereof as well as changes in the particular forms described, are
possible within the spirit and scope of the present invention.
Therefore, it is desired that the present invention shall not be
limited except insofar as it is made necessary by the prior art and
by the spirit of the appended claims.
* * * * *