US3638283A

US3638283A - Interconnecting member for tension loads

Info

Publication number: US3638283A
Application number: US36524A
Authority: US
Inventors: Anthony L Moretti
Original assignee: Bullard Co
Current assignee: Bullard Co; E D Bullard Co
Priority date: 1970-05-12
Filing date: 1970-05-12
Publication date: 1972-02-01
Anticipated expiration: 1989-02-01

Abstract

An interconnecting member having a figure-8 configuration by which two loops or eyes are formed. Two S-shaped bodies constitute the principal parts of the member and are pivotally connected so that the loops or eyes can be opened for access to the loops. The pivotal connection is formed by a keyed pin that is spring biased to a position to lock the two members into a figure-8 shape The pin is axially slidable to permit the loop to be opened and is provided with a locking device that prevents inadvertent sliding movement.

Description

I United States Patent [151 3,638,283

Moretti 1 Feb. 1, 1972 [54] INTERCONNECTING MEMBER FOR 2,795,024 6/1957 Donaldson ..24/73 CE TENSION LOADS FOREIGN PATENTS OR APPLICATIONS [72] inventor: Anthony L. Moretti, San Rafael, Calif.

316,767 8/1929 Great Britain ..24/232 [73] Assignee: E. D. Bollard Company, Sausalito, Calif. 22 il May 2 970 Primary ExaminerD0nald A. Griffin Auomey-Townsend and Townsend [21] Appl. No.: 36,524

[57] ABSTRACT [52] U.S.Cl ..24/73 HR, 24/232 An interconnecting member having a c0nfigul-a'ion [51] Int. Cl ..A43c 11/08 by which two loops or eyes are formed Two S bodies [58] Flew of Search "24/73 73 73 73 constitute the principal pans of the member and are pivotally 24/230 2305 24] 232; 59/89 connected so that the loops or eyes can be opened for access to the loops. The pivotal connection is formed by a keyed pin [56] References cued that is spring biased to a position to lock the two members into UNITED STATES PATENTS a figure-8 shape The pin is axially slidable to permit the loop to be opened and is provided with a locking device that Clark et al prevents inadvertent movement 385,962 10/1883 Bracken... ..24/232 1,668,325 5/1928 Kreutz ..24/232 3 Claims, 9 Drawing Figures PAIENTE'DFEBI m2 31638283 INVENTOR ANTHONY L. IMO/P5777 9 WZ W ATTORNEYS INTERCONNECTING MEMBER FOR TENSION LOADS This invention relates to an interconnecting member for tension loads and more particularly to an interconnecting member that is secure in a closed position but readily movable to an open position for disengagement of the load.

The environment in which the invention is disclosed concerns a tool-balancing system wherein a substantial portion of the weight of a hand-held tool is counterbalanced by a system that includes a cable or the like attached to the tool which cable is trained over a pulley so that the force of gravity acting on a weight at the opposite end of the cable counterbalances the weight of the tool. In such environment the necessity for periodic maintenance, repair, or replacement of the tool necessitates disengagement of the tool from the cable; the present invention provides a connector which affords such ready disengagement.

The specific embodiment of the present invention that is disclosed in more detail hereinafter includes a pair of generally identical S-shaped members which when placed in back-to-back relationship define a pair of closed loops or eyes. One of the eyes is intended for engagement with a suitable loop or ring on the tool and the other eye is adapted for engagement with a loop on the counterbalance cable system. Centrally of the two eyes is a pivotal connection which permits movement of the S-shaped members relative to one another to open the eyes. The axis of such pivotal movement is formed by a pin which has an axially extending key thereon that cooperates with keyways formed in the S-shaped members. The pin is axially slideable so that the key can be disengaged with at least one of the keyways to afford relative pivotal movement between the S-shaped members. A spring is provided for axially biasing the pin so that the key engages the keyways and the pin is provided with a locking hub which inhibits inadvertent axial movement of the pin against the spring.

An object of the present invention is to provide a connector of the type referred to above that is secure against inadvertent disengagement. Contributing to the attainment of this object is the locking pin to which reference has been made. Also contributing to such attainment is the configuration of the S- shaped hooks; the S-shaped hooks have curved portions at their extremities that curve back or return toward the main body of the S-shaped portions so that tension forces on the connector do not tend to separate or rotate the S-shaped members relative to one another.

Another object of the invention is to prevent inadvertent axial movement of the previously mentioned locking pin toward an unlocked position. Achievement of this object is important since the connector is subject to impact by the user of the tools supported thereby or by the workpiece, which impact if uncompensated would render the pin liable to inadvertent axial movement. The stated object is achieved by providing a knob on the pin that has a noncircular 'shape which cooperates with a similarly shaped opening in a hub to require proper rotational orientation between the knob and the opening in the hub to afford axial movement of the pin. A torsion spring is provided for biasing the noncircular hub away from a position of registry with the similar opening in the hub to the end that the connector can be unlocked only by intentionally rotating the knob.

Still another object is to provide a connector that is of sufficiently low cost that it can be widely employed. Achievement of this object follows from the fact that the two principal parts of the device, generally S-shaped bodies, are for all intents and purposes identical so that they can be cast from the same or virtually identical molds.

The objects, features and advantages of the present invention will be more apparent after referring to the following specification and accompanying drawings in which:

FIG. 1 is a side view of an interconnecting member according to the present invention;

FIG. 2 is an edge view of the connecting member of FIG. 1;

FIG. 3 is a side view of the interconnecting member in an open position taken from the side opposite FIG. 1;

FIG. 4 is a view taken along line 4-4 of FIG. 1 showing the mechanism for limiting the relative pivotal movement of the parts of the interconnecting members;

FIG. 5 is a cross-sectional view through the center of the connector from which the pivot pin is omitted to reveal certain details of construction;

FIG. 6 is taken along line 6-6 of FIG. 2 and is similar to FIG. 5 with the pivot pin in place in a locked condition;

FIG. 7 is a view similar to FIG. 6 with the pivot pin in an unlocked condition on the interconnecting member in an open position;

FIG. 8 is a view taken along line 8-8 of FIG. 2 and showing the structure for locking the pivot pin against inadvertent axial movement; and

FIG. 9 is a view similar to FIG. 8 and taken along line 99 of FIG. 7 showing the pivot pin in an unlocked position.

Referring more particularly to the

drawings reference numerals

12 and 14 indicate substantially identical S-shaped bodies which form the principal parts of the present invention. Each of the bodies includes a relatively straight bight portion 16, a relatively large curved portion 18, and a relatively small curved portion 20. See FIG. 3. Curved portion 18 at the end thereof includes a leg 22 that returns toward bight 16 and curved portion 20 includes a similar return leg 24 that is somewhat shorter than leg 22.

Bights 16 of each of S-shaped

members

12 and 14 include a central hub 26 projecting from one face thereof; the hubs are provided with concentric bores or

openings

28 and 29, respectively. As can be seen in FIG. 5, opening 28 includes a relatively large diameter counterbore 30 and a relatively small diameter portion 32 interior thereof. The wall of portion 32 is formed with a keyway 36 that opens axially into large diameter portions 30. Keyway 36 includes an axially extending sidewall 38 and an oblique sidewall 40 which converges from large diameter portion 30 toward the inner end of small diameter portion 32.

Opening 29 includes an outer portion 42 that has a relatively large diameter and an inner portion 44 that has a diameter substantially equal to that of inner portion 32 in opening 28. Portion 44 has formed in the wall thereof a keyway 46 that has an axially extending wall portion 48 and an oblique portion 50. Oblique surface 50 diverges from relatively large diameter portion 42 toward the inner end of small diameter opening 44 at the same angle as does surface 40 of keyway 36.

Keyways

46 and 36 are rotatively positioned with respect to the respective hook-shaped bodies so that when the hooks are moved to.

a closed position as shown in FIG. 1 the keyways are in axial alignment. By axial alignment is meant that when surfaces 38 and 48 are axially aligned, surfaces 40 and 50 lie along the same oblique line. Opening 29 is completed by a portion adjacent the outer end thereof that is of noncircular shape; a suitable manner for providing such noncircular shape is to provide two diametrically opposed axially extending slots 52 in the wall of outer portion 42.

For pivotally connecting

bodies

12 and 14 in operative relationship, a pin 54 is provided for extending through

openings

28 and 29. Pin 54 includes a head 56 that fits into relatively large diameter portion 30 of opening 28. On the opposite end of pin 54 is a section of reduced diameter'58. Intermediate ends 56 and 58, the pin has a cylindric portion that forms the axis about which the parts rotate. For retaining the pin in place a knob 60 is secured to portion 58 by swaging or like expedient which permits knob 60 to rotate with respect to the pin but prohibits relative axial movement of the two parts. Knob 60 is of noncircular form complementary to the noncircular portion of opening 29, and in the specific embodiment shown in the drawings the knob has two diametrically opposed keys 62 which fit into slots 52 when knob 60 is properly rotatively positioned. Circumscribing pin 54 within large diameter portion 42 of opening 29 is a compression spring 64. As viewed in FIG. 6, the outer or right-hand end of spring 64 bears against the underside of knob 60 and the lower end bears against a shoulder that exists between large diameter portion 42 and small diameter portion 44 of opening 29. Spring 64 also includes axially extending tangs which engage suitable recesses in the opening 29 and in the undersurface of knob 60 so as to bias knob 60 both rotatively or torsionally with respect to hub 26. In this respect spring 64 is configured so as to bias knob 60 to the position shown in FIG. 8, a position at which keys 62 are spaced 90 from openings 52.

Shaft 54 adjacent head 56 is formed with a tapered woodruff key 66 for cooperating with

keyways

36 and 46 in

openings

28 and 29, respectively. Key 66 is so formed that when pin 54 is biased inward by spring 64, the key engages the keyway and inhibits relative rotation of S-shaped

bodies

12 and 14. In such position the bodies define two closed loops as shown in FIG. 1. Axial movement of pin 54 away from the position just described is inhibited by knob 60 until the knob is rotated so that keys 62 are in axial alignment with slots 52 at which time the knob and shaft 54 can be moved axially to disengage key 66 from keyway 46 in S-shaped member 12. See FIGS. 7 and 9. At that position relative rotation of S-shaped member 12 with respect to S-shaped member 14 is possible so as to permit access to the interior of the eyes formed on opposite ends of the structure. See FIG. 3.

In order to limit the amount of relative rotation between S- shaped

bodies

12 and 14, the former has a pin 68 (See FIG. 4) that projects in a direction parallel to the axis of pin 54, and the latter has a slot 70 in which the pin slides. Slot 70 is concentric with the axis of pin 54 and is circumferentially limited to an arc of about 90. See FIG. 1.

The operation of the device is as follows: the knob 60 is depressed so as to disengage key 66 from keyway 46 and thus permit relative rotation of S-shaped body 12 with respect to S- shaped body 14 to move the device to an open position. In the open position a loop in the cable is engaged in curved portion 18 and the loop on the tool is engaged with the curved portion 20. The S-shaped bodies are then pivoted with respect to one another to the locked position at which the cable loop and the tool loop are retained captive within the eyes formed by the structure when in the closed position. Because of the

return portions

22 and 24 of the S-shaped members, tension force on the device does not tend to open the device but rather tends to retain it in the closed position; any tendency to open either of the eyes is resisted by engagement between key 66 and

keyways

36 and 46. Impact forces on the device, for example on knob 60 cannot cause inadvertent unlocking of the device because keys 62 rest on the upper surface of hub 26 on S- shaped member 12. When it is desired to remove the tool for repair or replacement knob 60 is rotated to bring key 62 into alignment with slots 52 and the knob as well as pin 54 are moved axially against the force of spring 64 until key 66 disengages keyway 46. At this time the S-shaped members can be rotated with respect to one another to permit disengagement of the tool. Because the amount that return portion 22 returns toward bight l6 exceeds the amount by which portion 24 returns, the cable loop can remain engaged with the device while the tool is removed, a feature that renders removal and replacement of the tool more convenient. Cooperation between pin 68 on S-shaped member 14 and circumferentially limited slot 70 on S-shaped member 12 limits the amount which the device can be opened, a feature which also contributes to the ease of operation of the device.

Thus it will be seen that the present invention provides a tension connector that is simple to construct and operate and which is secure against inadvertent disengagement. Moreover the device is formed from a small number of relatively inexpensive parts.

Although one embodiment of the. invention has been shown and described, it willbe apparent that other adaptations and modifications can be made without departing from the true spirit and scope of the invention.

What is claimed is:

1. Apparatus for interconnecting first and second looped members against a tension force tending to separate the members comprisin first and second generally S-shaped members each said mem er having a central bight portion and first and second curved portions extending from opposite ends of the bight portion, said S-shaped members being formed so that when they are juxtaposed in back-to-back relation with the bight portions intersecting one another, said first curved portions are movable to a closed position at which they cooperate to define a first eye for engaging said first looped member and said second curved portions are movable to a closed position at which they define a second eye for engaging said second looped member, said bights having an opening therethrough at the intersection thereof, and means extending through said opening for affording a pivotal connection between said S- shaped members to permit movement of said members between the closed position and an opened position at which the ends of respective said curved portions are spaced from one another to afford access to said eyes, said pivotal connection affording means including means for locking said members against pivotal movement in the closed position, said locking means having first and second axially extending keyways in the openings in said bights, said keyways being in axial alignment when said members are in the closed position, a pin extending through said openings and axially slidable between a first position and a second position, means for resiliently biasing said pin toward said first position, and a key on said pin for engaging said keyways when the pin is in said first position, said key having an axial extent so as to disengage one of said keyways when said pin is in said second position.

2. The invention of claim 1 wherein one of said openings in one of said bights defines at the exterior surface of the associated S-shaped member a noncircular portion and a knob attached to said pin and having a noncircular shape complementary to said noncircular portion so that said knob can reside at a first rotative state without said portion to retain said pin in said first position and a second rotative state to permit entry of knob into said portion to permit said pin to move to said second position.

3. The invention of claim 2 including means for resiliently torsionally biasing said knob to said first rotative state.

Claims

1. Apparatus for interconnecting first and second looped members against a tension force tending to separate the members comprising first and second generally S-shaped members, each said member having a central bight portion and first and second curved portions extending from opposite ends of the bight portion, said S-shaped members being formed so that when they are juxtaposed in back-to-back relation with the bight portions intersecting one another, said first curved portions are movable to a closed position at which they cooperate to define a first eye for engaging said first looped member and said second curved portions are movable to a closed position at which they define a second eye for engaging said second looped member, said bights having an opening therethrough at the intersection thereof, and means extending through said opening for affording a pivotal connection between said S-shaped members to permit movement of said members between the closed position and an opened position at which the ends of respective said curved portions are spaced from one another to afford access to said eyes, said pivotal connection affording means including means for locking said members against pivotal movement in the closed position, said locking means having first and second axially extending keyways in the openings in said bights, said keyways being in axial alignment when said members are in the closed position, a pin extending through said openings and axially slidable between a first position and a second position, means for resiliently biasing said pin toward said first position, and a key on said pin for engaging said keyways when the pin is in said first position, said key having an axial extent so as to disengage one of said keyways when said pin is in said second position.