U.S. patent number 3,836,043 [Application Number 05/214,008] was granted by the patent office on 1974-09-17 for transit/combination case shock mount arrangement.
This patent grant is currently assigned to International Telephone and Telegraph Corporation. Invention is credited to Herbert L. Levin.
United States Patent |
3,836,043 |
Levin |
September 17, 1974 |
TRANSIT/COMBINATION CASE SHOCK MOUNT ARRANGEMENT
Abstract
This invention comprises several embodiments of multi-functional
shock mounts for transit/cases. A resilient (e.g., rubber) molded
corner bumper is either bonded to, or captivated along its edges
by, a retainer shaped to be demountably coupled to a corner of the
case body or cover. The resilient molded portion may additionally
be provided with an outer metallic jacket to facilitate sliding and
protection thereof, the outer jacket in turn being either bonded to
the resilient portion or being captivated along with the rubber by
the retainer. The rubber bumper and its associated outer metallic
jacket are extended in a cubical shaped center portion beyond the
case outer dimensions and hardware, serving to recess same for
additional protection. The resilient molded bumper may be in the
form of a two or three-legged piece with the legs being retained by
the case outer structural members. Additional features such as male
and female stacking features, sloped edges to facilitate sliding,
and tie-rings are provided. Shaped coring holes or cast slots or
cross ribs in the resilient portion provide for the equivalent
spring constant in all dropping and handling modes to be closely
equal to the spring constant of the weight of the case and contents
on a corner support.
Inventors: |
Levin; Herbert L. (Wyckoff,
NJ) |
Assignee: |
International Telephone and
Telegraph Corporation (Nutley, NJ)
|
Family
ID: |
22797415 |
Appl.
No.: |
05/214,008 |
Filed: |
December 30, 1971 |
Current U.S.
Class: |
206/504; 206/512;
206/586; 220/732; 248/345.1 |
Current CPC
Class: |
B65D
81/056 (20130101); B65D 2581/055 (20130101); B65D
2581/056 (20130101) |
Current International
Class: |
B65D
81/05 (20060101); B65d 025/26 () |
Field of
Search: |
;220/1.5,85K,97B
;217/52,53,54 ;248/343.1,350,358 ;267/137-141 ;190/37
;229/14C,DIG.1 ;206/46FR,46FN,46M |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Price; William I.
Assistant Examiner: Marcus; Stephen
Attorney, Agent or Firm: O'Halloran; John T. Lombardi, Jr.;
Menotti J.
Claims
I claim:
1. A shock mount arrangement for transit type cases comprising a
transit case having a case body and a case cover each having a
plurality of corners, a bumper of resilient material mounted at
each corner of the case by way of a metallic member, each of said
bumpers being constructed to have a cooperating shape with the
corner associated therewith, each of said bumpers of said case
being provided with male and female stacking features arranged to
cooperate with more than two adjacent cases in a stacked mode, said
male and female stacking features comprising resilient protrusions
extending from and resilient recesses of corresponding shape
extending into said bumpers.
2. The arrangement according to claim 1 wherein said bumpers are
arranged to extend outward from the case beyond the case outer
dimensions and hardware.
3. The arrangement according to claim 2 wherein said bumpers
associated with the corners of the case body extend farther out
than those associated with the case cover.
4. The arrangement according to claim 1 wherein each of said
bumpers is bonded to a metallic corner member arranged to have
cooperating design with the associated case corner and bumper, said
metallic corner member being in turn demountably coupled to the
case.
5. The arrangement according to claim 4 wherein said metallic
corner member is adjacent to the associated corner in a
form-fitting manner.
6. The arrangement according to claim 4 wherein said bumpers are
provided with at least two legs of resilient material homogeneous
with and extending from a center portion and wherein said bumper
legs are bonded to respective metallic case members each of which
in turn is demountably coupled to the case.
7. The arrangement according to claim 5 wherein said resilient legs
are bonded to the underside of the edge members which in turn are
demountably coupled to the case.
8. The arrangement according to claim 1 wherein the center portion
of each resliient bumper is provided with cavities arranged to
provide predetermined shock absorption and distribution in
accordance with the contact experienced with foreign objects.
9. The arrangement according to claim 8 wherein said cavities are
cast elongated and tapered internal slots arranged to provide an
equivalent spring constant in all modes of bumper contact of
substantially the same as the spring constant resulting from the
weight of the case and its contents on a corner.
10. The arrangement according to claim 8 wherein said cavities are
in the form of elongated grooves provided on the undersides of the
bumper center portion for providing an equivalent spring constant
in all modes of bumper contact of substantially the same as the
spring constant resulting from the weight of the case and its
contents on a corner.
11. The arrangement according to claim 8 wherein said cavities are
in the form of crossed ribs on the outer and under surfaces of the
bumper center portion for providing an equivalent spring constant
in all modes of bumper contact of substantially the same as the
spring constant resulting from the weight of the case and its
contents on a corner.
12. The arrangement according to claim 1 wherein each of said
bumpers is retained by a metallic corner member arranged to have
cooperating design with the associated case corner and bumper, said
metallic corner member being in turn demountably coupled to the
case.
13. The arrangement according to claim 12 wherein said metallic
corner member forms an enclosed space with the case and contains a
plurality of apertures, and wherein each of said bumpers is
constructed with said metallic corner member so as to fill the
space provided between said corner member and the case and to be
homogeneous by way of said apertures with an outer molded resilient
portion which covers said metallic member.
14. The arrangement according to claim 13 wherein said outer
resilient corner portion is raised to extend beyond the case outer
dimensions and hardware and is of corresponding shape with the
corner for providing substantially flat outer contacting surfaces
which include said male and female stack features.
15. The arrangement according to claim 12 wherein said bumpers are
provided with at least two legs of resilient material homogeneous
with and extending from a center portion.
16. The arrangement according to claim 15 wherein said bumper legs
are retained by respective metallic case members, each of which is
in turn demountably coupled to the case.
17. The arrangement according to claim 16 wherein when the transit
case is of the type which includes outer structural edge members,
said bumpers are retained in position by the outer structural edge
members by way of the captivation thereby of said legs of said
bumpers in the space formed between the edge members and case.
18. The arrangement according to claim 17 wherein the center
portion of each of said bumpers is extended beyond the outer
dimensions of the edge members and case hardware.
19. The arrangement according to claim 18 wherein said corner
bumper center portion is substantially cubical in shape with the
exposed outer surfaces thereof being provided with male/female
stacking facilities.
20. The arrangement according to claim 12 wherein said metallic
corner member is coupled to the case by way of a demountable
retainer having a lip for retaining said metallic corner member in
place.
21. The arrangement according to claim 12 wherein said bumper of
resilient material is provided with a metallic jacket of
cooperating design on the exterior thereof.
22. The arrangement according to claim 21 wherein said metallic
jacket is bonded to said resilient bumper.
23. The arrangement according to claim 21 wherein said bumpers have
at least two legs of resilient material homogeneous with and
extending from a center portion, with each of said bumper legs
being retained by a metallic edge member which is in turn
demountably coupled to the case.
24. The arrangement according to claim 21 wherein said metallic
jacket is provided with male/female stacking features in the form
of protrusions and indentations of corresponding shape positioned
in an overlying relationship with said protrusions and said
recesses of said bumpers of said case body.
25. The arrangement according to claim 21 wherein said metallic
jacket is demountably coupled to the case.
26. The arrangement according to claim 25 wherein said metallic
jacket is provided with a ramp-like shape at the edges thereof.
27. The arrangement according to claim 25 wherein said metallic
jacket is coupled to the case by way of a demountable retainer
having a lip for retaining said metallic jacket in place.
28. A shock mount for exterior corners of a transit case adapted
for stacking, comprising a bumper of resilient material mounted to
a metallic member shaped to fit each of said exterior corners, each
of said bumpers having a stacking surface including one of
resilient protrusions extending from and resilient recesses
extending into said stacking surface, said protrusions and said
recesses having complementary shape.
Description
BACKGROUND OF THE INVENTION
This invention relates to transit cases, and more particularly to
the multi-functional shock mount arrangements for such cases.
In considering, for example, the very stringent requirements of the
military as to transit case construction and durability, two of the
most serious problems to be overcome in the design of transit cases
for military applications are: (1) the capability of the case with
a full dummy load to withstand 14 four-foot drops onto a concrete
floor, and (2) the capability of the case with internal equipment
to withstand 26 four-foot drops onto a plywood floor, and the
equipment to operate after testing.
Past results highlighted the problem of damage to existing transit
cases, and particularly the corners thereof, resulting from the
four-foot drop tests onto concrete or plywood floors. This is
particularly noteworthy in view of the fact that the drop tests are
considered unanimously by the industry to be destructive tests;
that the corners will be deformed; and that military specifications
may be interpreted as requiring that there shall be no evidence of
damage such as a crushed corner.
Present accepted methods of protecting transit case contents
against damage due to shock are: (1) to attach a "Transit Frame" to
the outside of the case, or (2) to place shock mounts between the
case and the inner chassis. These two military-approved methods,
however, have serious disadvantages:
I. The Transit Frame consists of a rectangular frame within another
rectangular frame with rubber bonded between them. The
disadvantages thereof are immediately apparent. The pair of frames
required for each case is heavy. They occupy a considerable
percentage of the total shipping volume. They are expensive, being
in the same price range as the case itself. The frame is removable
and therefore can be easily lost in the field. The transit frame
requires attachment to the case by means of cables and latches.
II. Shock mounts between the case and the inner chassis have the
following disadvantages: (a) they occupy the valuable inner volume
of the transit case; (b) they are not effective where the front
panel of the equipment chassis must be sealed to the transit case
to obtain a rain-proof feature; (c) they do not protect the outside
of the case, and particularly the corners of the case, against
damage due to, for instance, drop tests; and (d) they reduce usable
height and width of the chassis front panel.
SUMMARY OF THE INVENTION
It is, therefore, the principle object of this invention to solve
the problems of protecting a transit case from damage and to reduce
shock transmitted to the internal electronic equipment, while at
the same time avoid or eliminate the above-indicated drawbacks
associated with conventional arrangements.
It is another object of this invention to provide transit case
shock mount arrangements, designed to eliminate the problem of
corner mounts being ripped off when subjected to sliding, drop
tests and rough handling, as occurs, for instance, with
arrangements having the individual shock mounts cemented directly
to the case.
According to the broader aspects of the invention there is provided
a shock mount arrangement for transit type cases comprising a
bumper of resilient material mounted at each corner of at least one
surface of the case by way of a metallic member, each said bumper
being constructed to have cooperating shape with the case corner
associated therewith.
A feature of the invention is that each shock mount provided for an
exterior corner of the case may be adapted for a stacking mode
wherein the shock mount stacking surfaces are provided with male
and female stacking features of complementary design.
BRIEF DESCRIPTION OF THE DRAWINGS
The above-mentioned and other objects and features, and the
invention itself, will become better understood by consideration of
the following description when taken in conjunction with the
drawings, in which:
FIGS. 1A and 1B are respectively sectional and perspective views of
a corner bumper bonded to a metallic corner plate according to the
invention;
FIG. 1C diagrammatically illustrates a transit case with cover
showing the arrangement of corner bumpers thereon according to the
invention;
FIG. 2 is a perspective illustration of one embodiment of resilient
corner bumper according to the invention;
FIG. 3A is a perspective view of a corner of a transit case
illustrating an outer structural edge member;
FIGS. 3B and 3C illustrate respectively end and perspective views
of a second embodiment of resilient corner bumper according to the
invention in relation to the case corner and the outer structural
edge members as depicted in FIG. 3A;
FIGS. 4A and 4B are respectively diagrammatic side and perspecitve
views of a transit case wherein the inventive bumper arrangement is
provided with male and female stacking facilities;
FIG. 5 is yet another embodiment of corner bumper according to the
invention wherein the molded one-piece resilient portion is
comprised of inner and outer portions on either side of a
perforated retainer;
FIG. 6 shows a perspective view of a resilient corner bumper with a
metallic retainer for demountable coupling to the case corner;
FIG. 7 is a sectional view of a further embodiment of resilient
corner bumper wherein the resilient material is provided with a
metallic outer jacket;
FIG. 8 shows the embodiment of FIG. 2 in the arrangement
illustrated in FIGS. 3B and 3C, with the center portion of the
resilient corner bumper being provided with a metallic jacket;
FIG. 9A is a sectional view of a resilient bumper with metallic
jacket in arrangement with a metallic retainer demountably coupled
to the case;
FIG. 9B is a partial sectional view of an arrangement closely
similar to that of FIG. 9A, showing additional hardware and
friction reduction facilities;
FIGS. 10A-10C schematically represent the three drop modes required
in military case drop tests; and
FIGS. 11A-11C illustrate three individual means for compensation of
unequal forces in a corner bumper arising from the various drop
modes.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the figures in general, there is illustrated various
embodiments of corner bumpers for transit type cases. In FIG. 1A
there is seen a resilient and substantially non-permanently
deformable corner bumper 2, such as rubber, bonded to a metallic
corner piece or retainer 3, which metallic corner piece 3 is in
turn demountably attached to the case 1 by means of for example
screws, or alternatively by rivets or welding if other than a
demountable facility is desired. It is a direct advantage of this
arrangement that the molded rubber corner 2 can be bonded to a
small metal corner more strongly and at lower cost than it could be
bonded to the case 1 itself. There is also satisfied the military
requirements for a reinforced corner on a case. FIG. 1B shows in
perspective the relationship between the corner portion 2 and the
metal retainer 3 which comprise the inventive corner shock mount.
FIG. 1C on the other hand, schematically illustrates the
arrangement of the novel corner shock mounts on the transit case
body 1 and the cover 4 thereof, wherein the corner bumpers 2 are
such as to extend beyond the case hardware and outer dimensions,
recessing same for additional protection and reduced shock to the
contents of the case. It is to be noted in FIG. 1C that the bumpers
on the case body proper are such as to extend further than the
corner bumpers associated with the cover portion 4 of the transit
case 1. This provision is made in order that the cover does not
take the shock from drops on the flat side of the case and serves
to protect in general the cover portion from rough handling.
An alternative embodiment of the inventive resilient corner shock
mount is illustrated in FIG. 2, wherein the resilient portion 12
consists of a center portion and two or three legs extending
therefrom perpendicular from one another. The two or three-legged
resilient shock mounts may be assembled to the transit case 1 and
retained by the case outer structural edge members 5 as illustrated
in FIGS. 3A-3C. Whereas FIG. 3A shows the relationship of the outer
structural edge members 5 to the case itself, FIG. 3B represents a
sectional end illustration of the edge member 5 in relation to the
resilient member 12. Each pertinent edge member 5 captivates one of
the legs of the molded resilient corner 12 in the space provided
between the edge member and the case itself. In a preferred
arrangement thereof, the molded corner 12 may have its legs bonded
to one of the case edge members 5 and the edge members in turn are
demountably coupled to the case at 6. As shown in FIGS. 3B and 3C
the molded rubber portion has an extended center portion 12'
extending beyond the outer dimensions and hardware of the case.
FIG. 3C also illustrates in the resilient molded extended center
portion 12' male and female stacking features 7a and 7b. As
indicated, the male stacking feature consists of a substantially
circular disc homogeneous with and representing a further extension
to the extended center portion 12'. The female stacking feature 7b
represents a recess of corresponding shape. As represented at 7c,
the designer has the alternative of providing no stacking feature
or alternatively a male or female stacking feature on the third
side of the cubical-shaped center extended portion 12' of the
corner bumper. Also the male and female stacking facilities are not
limited in scope to substantially circular shape. A universal
bumper can be made through this invention having stacking features
herein indicated and oriented as required on any corner. The
arrangement illustrated in FIGS. 2 and 3A-3C particularly
eliminates the problem (encountered in the past when rubber corner
blocks were cemented to the case corners) wherein the rubber
corners were ripped off the case when subjected to drops, sliding,
and/or rough handling.
FIGS. 4A and 4B, in conjunction with FIG. 3C, further illustrate
the stacking features 7a and 7b molded into the rubber portion 2,
12 in order to interlock the cases when in a stacked mode, as
particularly seen in FIG. 4A. As mentioned hereinbefore, the corner
bumpers provided on the covers 4 of the transit cases 1 are
extended beyond the case outer dimensions to a lesser degree than
the corner bumpers on the case body itself, thereby providing a gap
8 (FIG. 4A) between the respective case covers in the stacked mode
in order to facilitate for instance the easy removal of the case
covers. The case corners, again, have been extended beyond the case
outer skin in order to provide a recess of the hardware, in
compliance with military specifications.
A further and alternative embodiment of corner resilient shock
mount according to the invention is shown in FIG. 5, wherein the
resilient portion is molded around and through a perforated metal
corner or retainer 3 so that bonding does not depend upon
attachment to the case, and in fact all metal-rubber bonding may be
eliminated. Here again, the resilient center portion is raised in
order to recess the case hardware, with the trapped or retained
portion 2' of the resilient corner being homogeneous therewith
through apertures 9 in the retainer 3. The retainer 3 is in turn
demountably coupled to the case 1, 4. FIG. 5 also illustrates at 7b
the possibility of stacking features as provided hereinbefore;
additionally, the resilient bumper portion is provided with sloped
edges 10 in order to facilitate sliding.
FIG. 6 illustrates a modification to the arrangement of FIG. 1A, in
that rather than having the resilient bumper portion 2 bonded to
the metallic retainer 3, the resilient portion is instead in effect
clamped to the case by the demountable coupling of the retainer 3
to the case, which serves to captivate the outer edges of the
resilient portion 2 between the retainer and the case. Here again
bonding of the resilient bumper portion to a metallic piece has
been avoided. A preferred alternative embodiment is illustrated in
FIGS. 7 and 8 wherein the rubber 2, i.e., the resilient corner
portion, contains an outer metallic jacket 11 which facilitates
sliding and distributes the shock load over a greater surface of
the resilient portion 2. In FIG. 7 the bumper portion 2 is
maintained between the metallic jacket 11 and the retainer 3, the
jacket 11 in turn being provided with male and female stacking
features as represented at 7b and also a sloping or ramp portion 10
to further facilitate sliding and reduction in friction. Metallic
jacket 11 is bonded to 2 which in turn is bonded to 3 which is in
turn attached to the case. FIG. 8 represents the embodiment of FIG.
3B, modified to include the outer metallic jacket 11. The metal
jacket 11 encloses the extended cubical center portion 12' of the
resilient bumper 12. In this manner the center extended portion 12'
is further protected from drops and rough handling and serves to
effect a reduction of friction in a sliding mode. As before, the
outer jacket 11 may be provided with the male and female stacking
features and corner sloping illustrated in FIG. 7. The outer metal
jacket in turn is bonded to the cubical extended center portion 12'
or alternatively may be demountably coupled to the case 1.
FIG. 9A shows yet another embodiment according to the invention
wherein the cubical shaped extended center portion 2 of the
resilient corner bumper is provided with a metallic jacket 11
having outside corners 11' extending beyond the case hardware,
wherein the resilient portion 2 and the metal jacket 11 are
provided with extensions at 15. The extensions in turn are
captivated by a retainer 14 which may be demountably coupled at 6',
such that the entire shock mount is retained by captivating the
extended portions of the jacket 11 and resilient portion 2 between
retainer 14 and the case itself. In this manner, bonding is not
required between resilient portion 2 and the case body 1, 4 or the
jacket 11. Thus once again there is provided a molded shock
absorbing material "sandwiched" between a metal outer jacket and
the case so that metal-rubber bonding is eliminated. The metallic
jacket 11 distributes the shock energy over the outer surface of
the shock absorbing material 2. The outer jacket 11, and
particularly at ramp 10, (FIG. 9B) provides for the equipment to
slide more easily on a rough surface without the corners being torn
or ripped off.
Additionally included with the metallic retainer 14 on
predetermined ones of the various transit case corners, and in
particular behind the raised or lip portion thereof which serves to
hold the shock mount in place, is a tie-down ring 16, shown
particularly in FIG. 9B. A groove or bent channel 16' is provided
in the retainer 14 at one corner thereof oriented 45.degree. with
respect to the retainer edges. The tie-down ring 16 included at the
various corners of the transit/combination cases permits same to be
strapped together and/or tied to ground stakes, for example, in a
stacked mode for additional stability. In a preferred arrangement
the tie-down rings 16, each having the shape of a D, would be
provided at the four corners of the case cover 4 for tie-down
requirements.
As shown in FIG. 9B, the retainer, in captivating the resilient
bumper portion 2 and its outer metallic jacket 11 between it and
the case, is either demountably coupled by, for example, screws at
6' or may be mounted by rivets or other suitable means if a
removable shock mount facility is not desired. Here again, in view
of the holding action of retainer 14, no metal-rubber bonding is
required as between the resilient portion 2, the outer jacket 11 or
the case itself. The tie-down ring 16 is similarly retained. As may
be seen, the retainer depicted in FIGS. 9A and 9B is shaped to
permit movement of the outer corner or jacket 11 in all directions
without metal-to-metal contact between the jacket 11 and the case
1, 4. Also particularly illustrated in FIG. 9B is the angled ramp
effect at 10 in the three-piece shock mount (i.e., resilient
portion 2, outer jacket 11 and retainer 14).
In all standard drop modes as illustrated in FIGS. 10A-10C a
different resilient (rubber) surface is offered as the absorbing
medium, while the weight remains constant. One would expect the
corner drop to have the greatest shock attenuation of all possible
dropping modes, since impact occurs through the least cross-section
of the rubber bumper 2, 12, and therefore the lowest spring
constant. The vibration frequency of the weight W on a corner, due
to the lowest spring constant, would be the least of all dropping
modes. It is expected that if the vibration frequencies in the
other dropping modes are higher, as they would be with solid,
parallel-piped rubber type sections, less shock attenuation would
ensue for these modes. It is therefore desirable to shape the
resilient parts so that the equivalent spring constant in all modes
is closely equal to the spring constant of the weight on a corner
support. The shaping is done by coring holes at slots 18 (FIG. 11A)
or casting grooves 19 (FIG. 11B) or crossing ribs 20 (FIG. 11C) in
the rubber portion to change its cross-section. The optimum
cross-section as well as correct material and durometer is
determined largely by empirical methods.
In FIG. 11A, cavities or holes are internally provided in rubber
bumper portion 2 in the form of elongated and tapered slots 18. In
FIG. 11B on the other hand, cavities 19 are in the form of
elongated cross-sectionally tapered grooves in the under surfaces
of the resilient portion 2, whereas in FIG. 11C cavities 20 appear
as ribs of substantially constant cross-section and arranged in a
crossed pattern on both outer and under surfaces of the rubber
bumper 2.
There has been disclosed above several embodiments for
multi-functional shock mounts in particular for transit type cases.
A resilient (e.g., rubber) molded corner bumper is either bonded to
or captivated along its edges by a retainer shaped to be
demountably coupled to a corner of the case body or cover. The
resilient molded portion may additionally be provided with an outer
metallic jacket to facilitate sliding and protection of the rubber
bumper, and also to better distribute the shock load throughout the
resilient portion, the outer jacket in turn being either bonded to
the resilient portion or itself being retained along with the
rubber bumper by the retainer. The rubber bumper and its associated
outer metallic jacket may be extended in a cubical shaped center
portion beyond the case outer dimensions and hardware, serving to
recess same for additional protection. The resilient molded bumper
may be in the form of a two or three legged piece with the legs
being retained by the case outer structural members. Additional
features such as male and female stacking features, sloped edges to
facilitate sliding and tie-rings have been provided. Shaped coring
holes or cast slots or cross ribs in the resilient portion have
been provided for the equivalent spring constant in all dropping
and handling modes to be closely equal to the spring constant of
the weight of the case and contents on a corner support.
While the principles of this invention have been described above in
connection with specific apparatus, it is to be understood that
this description is made only by way of example and not as a
limitation on the scope of the invention as set forth in the
objects and features thereof and in the accompanying claims.
* * * * *