Information
-
Patent Grant
-
6203075
-
Patent Number
6,203,075
-
Date Filed
Friday, May 22, 199826 years ago
-
Date Issued
Tuesday, March 20, 200123 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- McCormick, Paulding & Huber LLP
-
CPC
-
US Classifications
Field of Search
US
- 292 113
- 292 97
- 292 100
- 292 247
- 292 DIG 49
- 292 DIG 30
- 292 249
- 292 66
- 292 129
- 292 98
- 292 DIG 11
- 292 8
- 292 109
- 292 DIG 42
- 220 326
-
International Classifications
-
Abstract
A latch is disclosed incorporating features allowing complete actuation i.e., engagement and disengagement of a latching hook on the side of the container from a latch handle on the face of the container thus allowing actuation of the latch hook even when the latch hook is itself inaccessible. The latch also features variability in the stroke of the hook and a design allowing its construction from plastic material.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to latches. More particularly, the invention relates to latches which are engageable and disenageable from an easily accessible area to an otherwise inaccessible area such as when a latch is actuatable from a front of a container and the latch hook is on the side of the container, the side of the container being obscured by other containers.
2. Prior Art
In the ensuing discussion the types of latches described are generally referred to as front opening latches since the first surface perceived by a user is considered to be the “front” of the container. In the discussion of the prior art hereunder and in the discussion of the invention, the term “front” is used generically to indicate the exposed surface of the container. This could actually be, however, any surface of the container.
Front opening latches of the prior art have been developed for the same purpose as the present invention; that is to allow operation of the latch where containers are stacked next to one another obstructing access to the sides of the container. Since other conventional latches reside on the side of the container or require movement out of the plane of the side of the container, operation of these would be severely impeded.
Two main categories of prior art latches are intended to satisfy the desire/requirement for front operation latches. These are 1) side mounted latches that are operable when access to box sides is limited and 2) top mounted latches.
In the first category (side mounted), an example of an arguably “front only” actuatable latch is known by the trade name “Hook Lock” and is illustrated in
FIG. 1
of this application. One of skill in the art will recognize this latch. The latch incorporates a cam design so that movement of the handle lever causes both an arcuate and a radial movement of the hook. Thus, upon moving the handle lever in the appropriate direction the hook moves into engagement with the keeper plate. Further movement of the lever in the same direction causes the hook to draw the keeper plate toward the cam of the handle lever. This action draws the container cover toward its base and provides a tight closure. The latch is sold as actuatable from the front only because if mounted in a recess in the container side, it is considered possible to slide one's finger between adjacent containers and actuate the latch without actually seeing more than the end of the lever. Clearly, this suffers the substantial drawback that the latch could not be actuated in this manner if the cover of the container was deep. If it were, the fingers of the user would not reach the latch. Thus, this type of latch is not a viable solution to the front only operation dilemma.
Top mounted latches provide more diversity in the front only operation forum since they truly operate from the exposed surface of the container. Prior art top mounted latches have certain inherent drawbacks with some types of containers (e.g., fluid tight containers). These latches thus leave the art searching for a better solution to the need for front only operation.
One type of top mounting latch is a bail spring latch such as that illustrated in
FIG. 2
of the disclosure. This type of latch, although effective in closing and tensioning a container lid, requires a “through the container” mounting. In containers commonly employed for transport of sensitive equipment where a fluid tight seal is required at all times, these latches require a very effective (expensive) dynamic seal. Dynamic seals of this nature are cost prohibitive, subject to failure and therefore do not provide a preferred solution.
Other prior art latches whether top or side mounted which operate well for their intended purpose cannot work where adjacent structures are concerned because of their requirement that they move out of the side plane of the container or where they don't, they simply cannot be easily actuated from the exposed surface of the container. The adjacent structure inhibits the movement and/or access to these latches and prevents operation thereof.
SUMMARY OF THE INVENTION
The above-discussed and other drawbacks and deficiencies of the prior art are overcome or alleviated by the front opening latch of the invention.
Although “front” is employed in this specification as the location of operability of the latch disclosed herein, it will be understood that any plane of the container on which the latch is employed could be the operation plane or surface. More specifically, the latch body could be mounted on the front, top, side, bottom or rear of the container depending upon how the container is being viewed. The more important concept of the invention is that the latch is completely operable from an exposed plane or surface of the container, while acting on an adjacent surface which may be obscured from access or view. This is particularly advantageous when said containers are stacked one atop another or next to one another, etc. The most ubiquitous example of such use is, of course, where many of such containers are stacked in such a way that they create a wall. In this situation, a box in the middle could be opened if the invention is employed but could not have been opened if many of the prior art latches were installed. Since this scenario is most common and the exposed plane of the container is generally considered the “front” by most people, the term “front” has been used herein as the generic descriptor. Limitation is not intended. The invention also has no dynamic seals and is operable using only one hand.
An important feature of the invention is variability in the available stroke for drawdown. By varying the distance between certain components of the invention the stroke is increased or decreased. This benefit is achieved while not affecting the motion of the hook perpendicular to the side of the container. In other words the attachment of the hook to the latch lever, discussed hereunder in detail, does not need to move laterally during drawdown regardless of the stroke of the latch. This concept cannot be achieved by the prior art and provides a significant advantage in function.
Another important feature of the invention is the designed in capability of the latch to be made from plastic materials. The latch is preferably made of thermoplastic polyester which would creep under loads normally associated with latches intended to secure covers to containers as is the current invention. To accommodate the loads in such a way that the desired material is employable, the surface area of load bearing components of the latch have been enlarged to enable sufficient strength of the inexpensive and relatively malleable material to be employed.
The latch of the invention generally comprises a latch body having several components mounted as a unit on one surface of a container and a hook that is disposed generally perpendicularly to the latch body and is selectively engageable with a strike mounted fixedly on a surface of the container adjacent the surface upon which the body is mounted. The latch operates over the generally perpendicular angle by facilitating control of the hook from a spring lever disposed on or in the body.
The latch develops about 100 lbf of closure force near the end of its stroke and securely holds the cover of the container in place and sealed. Operation force required by the user, however, remains very small at 10 lbf or less.
The latch is maintained in the closed position by either or both of an over-center pivot point arrangement relative to the principal drawdown force vector of the draw down assembly and a hold down catch in the latch body.
Another feature of the latch of the invention is a warning system indicating that the latch is not engaged. Since it is desirable to prevent the latch lever from being freely located beyond the outer plane of a container to which it is mounted (i.e., mounted in a recess), it is spring loaded to return to and stay in the down or closed position when it is disengaged. Since in this position the latch appears to be engaged it is advantageous in the preferred embodiment to provide a system to warn a user that the latch is not, in fact, engaged. This is provided by a movement within the body of the latch allowing a colored section to be visible if the latch is not engaged. This colored section is not visible when the latch is engaged.
The above-discussed and other features and advantages of the present invention will be appreciated and understood by those skilled in the art from the following detailed description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to the drawings wherein like elements are numbered alike in the several FIGURES:
FIG. 1
is an illustration of a prior art latch having some ability to be actuated from the front of a container;
FIG. 2
is an illustration of a second prior art front operated latch where a dynamic seal is necessary for the function of the latch;
FIG. 3
is a perspective view of a section of a container on which the latch of the invention is mounted in the loaded and secured position;
FIG. 4
is a perspective view of a section of a container with the latch of the invention mounted thereon in the unlatched position;
FIG. 5
is an exploded perspective view of the latch of the invention;
FIG. 6
is a cross-section of
FIG. 3
taken along Section Line
6
—
6
;
FIG. 7
is a perspective view of the latch of the invention removed from the container and in a partially raised condition to illustrate pin movement within a groove;
FIG. 8
is the view of
FIG. 7
with the closest wall of the base removed to provide a view of the interior of the latch of the invention;
FIG. 9
is an enlarged view of the groove in the latch of the invention;
FIG. 10
is a perspective view of the latch of the invention removed from the container wherein the lever of the latch is fully raised and the spring lever released;
FIG. 11
is a cross-section view of
FIG. 10
taken along Section Line
11
—
11
;
FIG. 12
is a bottom perspective view of the latch lever of the invention;
FIG. 13
is a perspective view of an alternate embodiment of the latch;
FIG. 14
is a bottom perspective view of the alternate latch lever;
FIG. 15
is a perspective view of the alternate base without other components;
FIG. 16
is a cross-section view of the latch taken along section line
16
—
16
in
FIG. 13
; and
FIG. 17
is a cross-section view of
FIG. 7
taken along section line
17
—
17
.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to
FIGS. 3 and 6
, the invention is illustrated in the engaged position. It will be appreciated from a review of these figures that the latch of the invention maintains all components on the exterior of the container to which it is attached, thereby requiring no dynamic seals. This is of great benefit to maintain the fluid tightness often required of the type of container for which the latch was developed. Additionally, this is a significant advance over prior art systems with respect to reliability and economy.
In order to understand the exteriorly visible componentry, reference to
FIGS. 7
,
8
,
9
and
10
should be had. Latch body
10
comprises base
12
with bosses
14
a
and
14
b
for receiving screws from within container
16
to attach latch body
10
thereto. It should also be noted that upon boss
14
b
a catch
18
is located to receive a similar feature on the latch lever discussed hereunder. Catch
18
provides assurance that latch lever
30
stays in the closed position even under the forces (e.g., gravity, impact with other structures, etc.) sustained during the impact of a drop of for example of 10-20 inches by careless personnel or due to perhaps a stack of containers falling over.
Base
12
further includes trap support
19
and trap
22
. Trap support
19
is preferably a continuation of base
12
which extends over the edge of the plane upon which base
12
is supported. Trap support
19
functions to provide trap
22
which is desirable in a preferred embodiment to prevent the hook from moving more than necessary to clear the strike and to stay within the recess thereby not breaking the plane of the surface of the container.
In a preferred embodiment trap support
19
further includes an extension
20
perpendicularly oriented thereto. Extension
20
includes a tang
24
which is dimensioned to be received in a depression
26
(see
FIG. 6
) of the container
16
to provide further restraint for the trap
22
. In this preferred embodiment a container must be specifically manufactured to be fitted with this latch. The embodiment is preferred due to the superior strength thereof without the use of additional fasteners. It should be noted, however, that the latch of the invention can be constructed without extension
20
so as to be employable as a retrofit on containers which have not been specifically designed for use with front opening latches of the invention having extension
20
.
Referring to
FIGS. 3-11
simultaneously, it can be seen that in operable communication with base
12
of latch body
20
is latch lever
30
. Preferably, latch lever
30
is nested within uprights
13
of base
12
. Lever
30
is required to articulate with base
12
to operate the mechanism of the invention. The articulation of lever
30
with base
12
is through an L-shaped groove
36
in base
12
and a dual pin system. The two pin structures
32
and
34
in communication with the base
12
, are designed to move in the L-shaped groove
36
to facilitate the desired movement of the various components of the invention (The terms pin structures are used here because there are actually two parts of each pin, the pin does not extend all the way across the latch. Hereafter the singular term pin will be employed for simplicity). It is important to note that pin
32
is a part of hook
38
(actually hook
38
splits at its upper extreme to form two hoops
38
a
and
b
to which the pins
32
are attached) and that movement of this pin causes the hook to move through its stroke. Since the desired movement of the hook
38
is substantially parallel to the principal force vector encountered in closing the container on which the latch is mounted, the section
36
a
of L-shaped groove
36
where hook pin
32
moves is also parallel to that principal force vector. Hook pin
32
is mounted in recess
31
of latch lever
30
so that lever
30
may rotate therearound and hook pin
32
transfers draw down force through the lever
30
to the cam surface
33
and then to base
12
.
Another important aspect of hook pin
32
is that it is mounted in such a way as to tend to keep the latch lever
30
closed. More specifically, hook pin
32
is mounted in recess
31
in lever
30
in a position allowing it to be just over-center of the cam surface
33
when the latch is in the closed position. This tends to maintain the latch in the closed position.
Referring specifically to
FIGS. 8 and 9
, latch pin
34
, as will be appreciated by a review of the drawings, has an unusual shape. The shape is important to operation of a preferred embodiment because it provides movement in desired directions only. Importantly, latch pin
34
having a generally triangular appearance facilitates features of the invention such as a latch open flag, positive return of the lever
30
to the closed position and urging of the hook downwardly for engagement or disengagement with the strike. From a review of
FIGS. 8 and 9
, one of ordinary skill in the art will note that angled surface
35
of latch pin
34
, which is preferably about 45° to an imaginary horizontal reference in the drawing, never moves off inside radius
37
of L-shape
36
when the latch lever
30
is in the closed position and the hook is not engaged. This is because if surface
35
were to move off radius
37
in the vertical portion
36
a
of L-shape
36
(i.e., when lever
30
is in the closed and unlatched position) it would not be possible for an operator to lift lever
30
without first pushing and holding the end of lever
30
down against the base
12
to move tip
41
from wall
43
of groove
36
. It will be appreciated that if tip
41
is against wall
43
, the lever cannot move because the two pins
32
and
34
on each side of lever
30
work against each other in groove
36
to hold the lever
30
in a nearly static state. Providing surface
35
does stay on radius
37
, however, when lever
30
is raised, pin
34
merely slides across radius
37
and into the horizontal portion
36
b
of groove
36
. The plastic coefficient of friction for a material of choice is preferably at less than about 0.3. The ability to use plastic for the invention is occasioned by the particular construction which spreads the load experienced by the latch over a relatively large surface area.
It should be noted that latch pin
34
is offset relative to hook pin
32
in order to provide a sufficient length of surface
35
to prevent that surface from moving off radius
37
. Thus when latch pin
34
is to rotate due to lifting of lever
30
, additional space must be provided. If the space of area
45
is not provided, tip
41
would contact the top and bottom walls of groove section
36
b
simultaneously and would prevent lever
30
from being fully raised. Enlarged area
45
is of a shape complimentary to tip
41
of latch pin
34
so that these parts may easily fit into the enlarged area. Because area
45
allows latch pin
34
to rotate 90° in groove
36
, lever
30
is rotatable to the fully raised position. Tip
41
bears on radius
47
of area
45
to provide downward leverage to hook pin
32
through lever
30
. The hook is therefore urged downwardly toward the end of its stroke when latch pin
34
is in area
45
. A benefit is achieved by the arrangement of the latch lever in the base of the invention in that very little actuation force (less than 10 lbf, loaded) relative to the drawdown force (approximately 100 lbf) is needed to open or close the latch when loaded. The use if the preferred plastic material permits the friction coefficient to be maintained below 0.5 with no lubricant.
The latch of the invention substantially avoids perpendicular movement relative to the principal force vector of closure. With respect to the terms “avoids perpendicular movement relative to the principal force vector,” it is assumed that firstly that one of ordinary skill in the art will appreciate that there is a principal force vector in a latch mechanism; secondly that the principal force vector existing in the latch of the invention will be along the hook since it is designed to be there and based upon the operation of components, that is where it in fact is; and thirdly that perpendicular movement relative to a vector, includes any movement having a perpendicular component to its movement. This is not to say that the pin
32
necessarily must move in the principal force vector but that it must move in a direction substantially parallel with that vector. The parallel movement may be within the vector but also may be outside the vector.
By moving lever
30
to the raised position the hook pin
32
is allowed (and urged against the bias of spring
58
by continued upward movement of lever
30
) to move toward the strike
39
causing the loading force of hook
38
against strike
39
to be released. During re-engagement of the latch of the invention (assisted by the operation of spring lever
50
discussed hereunder), hook pin
32
is moved away from strike
39
with hook
38
catching strike
39
. The draw down force created hereby is transmitted to the container cover and compresses a seal (not shown) on the parting line securing the cover to the base of the container. The mechanism of movement of the pin
32
toward strike
39
in the present invention provides the additional benefit of variability in the stroke of the hook
38
. By altering the distance between cam surface
33
and hook pin
32
as well as the length of the both portions of L-shape groove
36
, the effective stroke of the hook can be varied. The larger the distance between pin
32
and cam surface
33
(and commensurate lengthening of the groove
36
), the longer the stroke of the hook. This variability is available while maintaining the hook pin movement to a direction parallel to and proximate to the principal force vector during drawdown. This feature makes the latch of the invention extremely versatile while maintaining the other discussed benefits thereof.
In addition to the construction of the over-center pin position, referring to cross-section drawing
FIGS. 6 and 11
, lever
30
is maintained in the “down” position, redundantly, whether engaged or disengaged, by detent
40
which is preferably a downstruck projection from a center section of the latch lever
30
and positioned to align lip
42
of detent
40
with catch
18
of boss
14
b
. When the latch lever
30
is fully in the down position, lip
42
is engaged with catch
18
and remains in that position until deflected into disengagement by, in a preferred embodiment, button
44
located on the surface of latch lever
30
. In a preferred embodiment, button
44
is provided by severing the surface material of latch lever
30
on three sides to create a cantilevered portion that is easily deflected by placing pressure on the end thereof. Deflection ease of button
44
is assisted by chamfer
61
on lever
30
to permit a user's finger more room to deflect button
44
.
Each of the components of the latch of the invention are assisted in operation by a single spring. Spring
58
is located and secured in base
12
and provides cantilever spring tongue
59
to interact with other components as discussed hereunder. Spring
58
includes feet
63
(see
FIGS. 5 and 17
) at the ends of legs
65
which are provided to secure the spring. Feet
63
are adapted to fit within blocks
67
while legs are placed under leg holders
69
. It will be appreciated that these features are well illustrated on one side of the latch in
FIG. 8
, however the features are identically provided on the other side of the latch in a preferred embodiment. By employing a single spring for all functions, complexity, cost and assembly time are reduced. To understand operation of spring
58
, spring lever
50
must first be introduced. Spring lever
50
, best illustrated in
FIG. 5
, is preferably nested in latch lever
30
and pivotally mounted therein on spring pivot pins
52
. The pivot action of lever
50
facilitates one finger deflection of cantilever spring tongue
59
by depressing trigger surface
56
. Movement of spring tongue
59
is caused by spring tongue cam
54
bearing thereupon occasioned by actuation of trigger
56
(and by raising latch lever
30
). The movement imparted to spring tongue
59
by tongue cam
54
, causes it to bear against landing
60
on or in hook
38
. (It should be noted that landing
60
can be created by opening a hole in hook
38
(as illustrated) or by providing a projection from the rear surface thereof at an appropriate location to intersect with spring tongue
59
. Determining where to place the hole or projection is a matter easily accomplished by one of ordinary skill in the art following exposure to this disclosure and can be viewed representatively in the figures.) Returning to the operation of the invention, by urging spring tongue
59
toward container
16
, hook
38
is biased outwardly away from container
16
at roughly 90° to the direction of movement of spring tongue
59
and downwardly. This movement enables the movement of hook
38
with respect to strike
39
to disengage the latch of the invention. Actuating of trigger
56
is necessary to this movement since without actuating trigger
56
the natural bias of spring
58
is away from container
16
. The natural bias is useful during a disengagement operation since it provides the impetus needed to misalign hook
38
with strike
39
and facilitate the disengagement of the latch.
During the disengagement operation, when latch lever
30
is opened (moved away from container
16
) without actuating the spring lever, the hook
38
is biased upwardly and outwardly by the spring. When the load on the strike is removed, the natural bias of spring
58
moves hook
38
into misalignment with strike
39
and the latch is disengaged. When the lever
30
is released, it is urged down into the closed position by the continued upward urging force of the spring on hook
38
.
Reengagement of the latch of the invention is a simple one hand operation. Lever
30
is raised to the upright position and trigger
56
is actuated. These two actions cause hook
38
to be urged into a position where it is aligned with strike
39
. Lever
30
is then moved back to the closed position while holding trigger
56
and hook and strike engage and provide draw down force to the cover of container
16
. Upon restoring latch lever
30
to the closed position, approximately 100 lbf of draw down force is developed in hook
38
and detent
40
snaps lip
42
into engagement with catch
18
of boss
14
b.
In a preferred embodiment of the invention the exact placement of pin
32
, size and shape of pin
34
as discussed and the length of groove
36
is important for a safety feature. Since the latch lever is always biased into the closed position it would be difficult to know if the container was indeed latched shut without checking each of the latches. Visually checking the hook and strike of the latches can be extremely difficult in a wall of containers for the same reasons front operation latches are needed. To alleviate this time consuming, difficult, and often inconclusive procedure, the inventor hereof has devised a warning system as follows and is illustrated in FIG.
4
: By allowing room at the top of groove
36
, pin
32
is permitted to move high enough to allow latch lever
30
to become slightly unnested in base
12
. Pin
34
also moves up groove
36
but as previously stated never moves beyond radius
47
. Lever
30
moves upwardly from base
12
approximately ⅛
th
inch by the natural bias of spring
58
when hook
38
is disengaged from strike
39
. By providing a brightly colored surface
70
on each side of latch lever
30
that is only visible when the latch lever has been elevated by the ⅛
th
inch due to the hook
38
not being engaged, a quick visual check of the latch will immediately inform the user as to the condition of the latch. When the latch is fully engaged the brightly colored surfaces are completely concealed by upright members
13
of base
12
.
An additional and significant benefit of the latch of the invention apart from its fully front only operability is that the forces developed and encountered by the operation of the latch are placed and oriented in such a way that a plastic material such as a thermoplastic polyester, preferably Valox™ can be employed to make these parts. In fact, all parts except the spring
58
, hook
38
and strike
39
in the preferred embodiment are constructed of plastic. Spring
58
is preferably constructed of stainless spring steel although other materials could be substituted, as is recognized by one of skill in the art, including plastic. Strike
39
and hook
38
are preferably constructed of aluminum (although again other materials could be substituted which have a yield strength of higher than 40,000 psi).
Referring to
FIG. 12
, lever
30
is illustrated apart from all other parts of the invention and from the bottom to illustrate structure that makes possible the employment of plastic material. As can be appreciated from
FIG. 12
, cam surface
33
is made up of preferably four force bearing surfaces
33
a-d
. These surfaces distribute the static closure force of the latch. The surface area to be provided is selected so that with a static closure force of 30 lbs, the compressive stress is less than 500 psi and the long term strain at the maximum operating temperature will be less than 2%. The arrangement enables the latch lever cam surface
33
to withstand extended use without significant creep(causing failure or reduction of efficiency). Another area of concentration of forces on a plastic surface is at recess
31
. The recesses are each dimensioned to achieve a large surface area to spread the forces experienced. One of ordinary skill in the art having been exposed to this disclosure will recognize that pin
32
of hook
38
is significantly larger than it might be if the latch was constructed of metal. Also visible in
FIG. 12
are finger rest protuberances
29
which act both to strengthen the latch lever
30
and to provide comfort to the user.
It will be understood that the latch of the invention can certainly be constructed of material other than plastic (e.g. metal) and may employ surface areas for bearing loads which are below those preferred herein for the use of plastic. This is due to the inherent structural rigidity of metal and should be appreciated by one of skill in this art.
In an alternate embodiment of the invention, several features are modified. Referring to
FIGS. 13-16
, button
144
is visible. Button
144
replaces button
44
in the previous embodiment. Button
144
includes downstruck member
140
with lip
142
to engage catch
118
on boss
114
b
. Button
144
is articulated within latch lever
130
on pin
170
in boss
172
on either side of latch lever
130
. Button
144
and member
140
are together actuable by depressing button
144
downwardly against spring
174
to disengage lip
142
from catch
118
. Button
144
further includes stop
176
to maintain button
144
in the appropriate position when lip
142
is not engaged with catch
118
. In a preferred arrangement, button
144
includes ridges
178
for a sure grip. This embodiment is identical in all other respects with the previous embodiment except for the extension and tang of the prior embodiment. In the present embodiment there are two extensions
120
and two tangs
124
as illustrated in FIG.
13
. These function in the same way as the prior embodiment.
While preferred embodiments have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustration and not limitation.
Claims
- 1. A single plane operated dual plane latch comprising:a latch base adapted to be disposed on a first plane; a hook operably connected to said latch base at an articulation point and adapted to extend along a second plane, said second plane being substantially perpendicular to said first plane; a strike adapted to be mounted to said second plane and adapted to selectively be engaged by said hook; a latch lever including a lever pin, said latch lever being adapted to have a securing lip for releasably securing said latch lever to said latch base; and wherein said articulation point includes a hook pin and said latch base includes an L-shaped groove in which said lever pin and said hook pin move, said lever pin is of a generally triangular shape selected to maintain said lever pin in predetermined areas of said L-shaped groove.
- 2. A daul plane latch as claimed in claim 1 wherein the latch lever includes surface area comprised of a recess in said latch lever adapted to secure said hook pin and a cam surface on said latch lever upon which said latch lever slides is constructed to sustain a compressive force of <500 psi and long term strain of <2% under a static closure force of about 30 lbs.
- 3. A dual plane latch as claimed in claim 2 wherein said latch lever includes a cam surface and a stroke of said hook is determined by a distance between said cam surface and said articulation point.
- 4. A dual plane latch as claimed in claim 1 wherein said latch lever is adapted to partially unseat from said latch base when said latch is not loaded.
- 5. A dual plane latch as claimed in claim 4 wherein said latch lever includes a brightly colored indicator surface that becomes visible when said latch lever is not loaded.
- 6. A latch comprising:a base attachable to a first plane; a latch lever in operable communication with said base; a spring lever including a deflecting cam in operable communication with said latch lever; a hook in operable communication with said latch lever and selectively attachable to a second plane, said hook including one of a landing and an opening formed on a distal end thereof; a strike attachable to said second plane, said strike being selectively engageable by said hook; a spring mounted to said base and in operable communication with said spring lever and said hook, said spring includes an elongated tongue in operable communication with one of said landing and said opening, said spring is selectively biased by said deflecting cam, thereby urging said hook to disengage from said strike; and wherein said tongue selectivly urges said hook into engagement with said strike when said spring is not biased by said deflecting cam, and said tongue comes into contact with one of said landing and said opening when said spring is biased by said deflecting cam.
- 7. A latch as claimed in claim 6 wherein said base further comprises at least two L-shaped grooves on either side thereof to provide articulated engagement of said latch lever.
- 8. A latch as claimed in claim 7 wherein said latch lever includes:at least one recess for receiving at least one hook pin connected to said hook; at least one lever pin wherein said at least one hook pin and at least one lever pin are receivable in at least one of said at least two L-shaped grooves, said lever pin having a shape to facilitate desired movement of said latch lever in said at least two grooves.
- 9. A latch as claimed in claim 6 wherein said latch further comprises:a detent having a lip connected to said latch lever; a catch disposed on said base whereby when said detent and said catch are engaged the latch is maintained in a closed position.
- 10. A latch as claimed in claim 9 wherein:said spring biases said hook into engagement with said strike when said lip is engaged with said catch; and said spring biases said hook into disengagement with said strike when said lip is disengaged with said catch.
- 11. A latch as claimed in claim 6 wherein:said first plane and said second plane are substantially perpendicular to one another.
- 12. A container latch operable from a single surface comprising:a latch body having a base, a latch lever articulated in said base, a spring lever articulated in said latch lever and a spring mounted in said base and in operable communication with said spring lever; a hook having a first catch and a pin, said pin being operably received in said latch lever; a strike having a second catch complimentary to said first catch whereby when said hook is oriented to catch said strike, a reliable hold down anchor is provided; and wherein said base and said hook are oriented substantially perpendicular to one another.
- 13. A container latch operable from a single surface as claimed in claim 12 Wherein said base further includes a trap support extending generally perpendicularly to said base, said trap support having a trap disposed thereon, said trap being engaged with said hook.
- 14. A container latch operable from a single surface as claimed in claim 13 wherein said trap support further includes a tang thereon said tang being receivable in a depression in a container upon which said latch is mounted.
US Referenced Citations (21)