Note: Descriptions are shown in the official language in which they were submitted.
11043ZS
BACKGROUND OF THE INVENTION
. . _ _ . .
Various attempts have been made to provide the simple and
convenient arrangement for removably attaching a load support
device such as a hook to a load support link which may be part
of a chain. Of these, the simplest form would appear to involve
forming the hook with a clevis whose legs are spaced apart suffic-
iently to receive the end link of a load chain and are through
bored to receive a load pin, which is sized to be slip-fitted
through the last link and to be end supported within the bore
openings.
In these prior constructions, the load pins have been norm-
ally formed with either a circular or an oval cross-sectional con-
figuration; the latter design serving to maximize shear strength
and resistance to bending. Prior constructions of this type are
disclosed for instance by U.S. Patents 1,393,568 and 1,562,908.
SUMM~RY OF THE INVENTION
The present invention is directed towards an improved load
support device load pin retention system and more particularly to-
wards an improved clevis construction facilitating load pin assem-
bly/disassembly operations, while minimizing th~ likelihood ofunintentional removal of the load pin from operative engagement
with the clevis and load lift means during use of the load support
device.
The invention in one broad aspect pertains to a load support
device removably attached to a support link of a load lift means.
The device includes a hook body formed integrally with a clevis
having a pair of leg portions spaced apart and receiving the link
therebetween. A first of the leg portions is formed with a first
bore opening and a second of the leg portions is formed with a
second bore opening arranged in axial alignment with the first bore
- opening. The device also includes a load pin of oval cross-
sectional configuration, the load pin having a widthwise minimum
dimension sized to permit the load pin to be slide fit within the
link while constrained from rotational movements relative
~P
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11(~4325
thereto and a l-leightwise maximum dimension sized to permit the
load pin to ~e slide and rotatably fit within the first and second
bore openings. Retaining means are provided for releasably re-
taining the load pin within the Eirst and second bore openinys.
The invention in another aspect pertains to the
combination of a lold support device, a link, a load pin for attach-
ing the load support device to the link ancl retaining means for
releasably retaining the load pin assembled relative to the load
support device. The load support device is characterized as having
a pair of leg portions spaced apart for receiving the link there-
between and formed with axially aligned openings to receive opposite
ends of the load pin. The improvement in the combination lies in
the openings being bore openings and the load pin being formed with
a widthwise minimum dimension sized to permit the load pin to be
slide fit in the link while constrained from rotational movements
relative thereto and a heightwise maximum dimension sized to permit
the load pin to be slide and rotatably fit within the bore opening.
Other aspects of the invention will become appar-
ent from a review of the drawings and detailed description herein
of the preferred embodiment of the invention.
DRAWINGS
The nature and mode of operation of the present
invention is now more clearly described in the following detailed
description of a particular hook and lift chain embodiment, taken
with the accompanying drawings wherein:
FIG. 1 is a front elevational view showing a hook formed in
accordance with the present invention in association with a load
chain;
FIG. 2 is a side elevational view thereof;
FIG. 3 is a sectional view taken generally along the line
3-3 in Fig. l; and
FIG. 4 is a sectional view taken generally along the line
4-4 in Fig. 2.
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DETAILED DESCRIPTION
Reference is now made particularly to Fig. 1, wherein
10 generally designates a hook characterized as including in-
tegrally formed hook body and clevis portions 12 and 14, re-
spectively, wherein clevis first and second leg portions 16 and
18 respectively, are shown as being spaced apart sufficiently to
receive the last link 20 of a load chain therebetween. A load
pin 22 is adapted to be removably inserted through last link 20
and have its opposite ends supportingly received within first and
second aligned openings 24 and 26 of clevis leg portions 16 and
18, respectively, for the purpose of removably interconnecting
the hook and load chain.
In accordance with the preferred form of the
present invention, load pin 22 is of an oval cross-sectional con-
figuration, wherein its widthwise, minimum dimension is slightly
less than the width of space within last link 20, whereby to
permit slip fitting of the load pin within last link 20, whil
constraining rotational movements therebetween. On the other
hand, the heightwise, maximum dimension of load pin 22, is
slightly less than the size of clevis leg portion openings 24
and 26, which are preferably "bore" openings of circular cross-
sectional configuration, whereby to permit both rotational and
sliding movements of the load pin relative to the clevis. This
arrangement is preferable to prior constructions, which prevent
rotation of oval load pins relative to the clevis and thereby
cause all relative movements to occur between last link 20 and
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next to last link 28, such that the load chain is subject to
non-uniform wear conditions. In the present construction
wherein load pin 22 is journaled by the clevis, the problem of
non-uniform chain wear is alleviated without substantially
shortening the life of the load pin and/or clevis due to the
substantial bearing area therebetween and the ability to choose
materials for the load pin and/or clevis having substantially
greater resistance to wear than the material from which the
chain is conventionally formed. It would be preferable,
however, to limit wear to the load pin inasmuch as it may be of
; relatively inexpensive construction and easily replaced.
~ .
Further, in accordance with the present
invention, a shield portion or abutment "hood" 30 is carried by
leg portion 18 for the purpose of partially blocking or
extending across the outer end of second bore opening 26,
whereby to define an abutment arranged for engagement by the
inserted end surface 22a of load pin 22, when the latter is
inserted in succession through bore opening 24, link 20 and bore
opening 26 during an assembly operation. However, shield
portion 30 does not wholly block or cover the outer end of bore
opening 26, thereby permitting insertion of a suitable tool,
such as a drive punch, not shown, thereinto, for the purpose of
forcing or driving load pin 22 from assembled relationship with
clevis 14 and the last link 20 whenever the load pin has become
worn and/or it is desired to disconnect the hook from the load
chain. The illustrated configuration and positioning of shield
portion 30 is nonetheless effective in preventlng the
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`` 1~043Z5
unintentional engagement of external objects with inserted end
surface 22a of load pin 22, during normal use of hook 10. More
specifically, shield portion 30 is preferably formed integrally
with leg portion 18 and arranged to project outwardly therefrom
in a direction away from leg portion 16 and from adjacent its
~; free or upper end in a direction downwardly towards hook body
portion 12, as best shown in Figs. 1 and 4. As best shown in
Fig. 2, shield portion 30 is sized to overlie essentially one-
half of bore opening 26 and is formed along its free or lower
10 edge 32 with a drive punch receiving recess or notch 34 disposed
essentially in alignment with the axis of bore openings 24 and
26. The term "partially blocking", as applied to shield portion
30, is meant to additionally include a construction, wherein the
shield portion completely bridges across bore opening 26 and is
formed with an axially extending through opening sized to
receive a load pin removing punch.
Now referring primarily to Figs. 1 and 4, it will
be understood that the lengthwise dimension of load pin 22 is
such that its opposite or outer end surface 22b is disposed
20 within and spaced inwardly from the outer end of bore opening
- 24, when load pin 22 is fully inserted to position its inserted
end surface 22a in abutting engagement with shield portion 30.
Load pin 22 may be removably retained in its full/y inserted
~; position by forming leg portion 16 with a third bore opening 36,
which is arranged to extend in a traversely directed
intersecting relationship with bore opening 24, and removably
fitting a suitable retaining pin device 38 within bore opening
11043ZS
36 for engagement with load pin end surface 22b. Pin device 38
may be variously defined, as for instance by a roll pin, set
screw or the like, but preferably has its opposite ~nds
supported within bore opening 36, such that its mid portion is
arranged to engage opposite end surface 22b. Upon removal of
retaining pin device 38 by an operator, load pin 22 may be
- removed from assembled relationship with clevis 14 and last link
20 in the manner described above.
The above described construction is economical
from ~he standpoint that load pin 22 may be ormed of uniform
cross-sectional material and need be only of a length sufficient
to provide for proper bearing engagement of its ends with the
surfaces of bore openings 24 and 26. Moreover, the present
construction has the advantage that one end of load pin 22 is
releasably retained within bore openings 24 and 26 by the
expedient of forming leg portion 18 with integral shield portion
30, which although serving as a permanent abutment for the load
pin and preventing unintentional engagement thereof with
external objects during normal use of hook 10, nonetheless
permits ready operator access thereto when required to remove
; same from coupling engagement with clevis 14 and last link 20.
Further, the provision and arrangement of pin device 38 serves
to shield this additional load pin retainer, as well as the
opposite end of the load pin, from engagement with external
objects during use of the hook, and does not require the simple
construction of the load pin to be modified in any way for the
purpose of co-operating with the retaining pin.
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1~0~3Z5
Although, the invention has been par~icularLy
described in relation to a load hook and lift chain
embodiment, it will be appreciated by those skilled in
the art that the invention comprehends and has utility
with other load support devices where such devices
have a clevis construc-tion operatively associated through
a load pin assen~ly or construction with a link means of
a load lift means.
