This invention relates to electrical power connectors and more particularly to a connector set having both combination primary and secondary locks for maintaining the power connector set in an engaged relationship.
Power connector sets used for high electric power connection generally consist of male and female connector members which are often provided with locking devices which interact between the two members to prevent accidental separation of the two members.
A standard type of lock is a bayonet lock where one of the members carries a key or projection which can be inserted into a groove or slot in the other member during coupling of the two members, the slot being L-shaped or J-shaped or otherwise configured. A known bayonet configuration is one that requires the key to move axially in the slot to a first axial position at or near an end of the slot before permitting rotation to occur and upon rotation requires, or allows, the key to undergo a slight axial movement in the opposite direction such that the key bearing connector cannot be rotated again with respect to the bayonet slot carrying member without the members undergoing relative axial movement towards one another.
The use of bayonet slots in coupling electrical connectors together is well known and is shown, for example, in U.S. Pat. No. 5,423,692 where a straight L-shaped bayonet slot is used which does not require retro axial movement to occur before rotation from the unlocked to the locked position.
While such bayonet connections are effective in preventing separation of the connector members when the key has been rotated into the circumferentially extending slot at the end of the axial entrance slot of the bayonet slot, they do not protect against unauthorized disconnection either intentionally or by vibration causing relative rotational movement between the connectors.
For this reason it has been proposed to provide a secondary lock which prevents the rotation of the key in the bayonet slot from its locked position in the absence of a determined secondary lock unlocking action. Preferably the determined unlocking action may require a tool to disengage the secondary lock. Such a combination of a bayonet slot and a secondary lock requiring use of a tool for intentional unlocking is shown, for example, in U.S. Pat. No. 5,685,730. The secondary lock as shown in that patent incorporates an axially spring biased pin in one of the connector members, which, upon rotation of the key in the bayonet slot, will project into a radially outer diameter open slot which is also open to an axial said face in the other member, the pin having a degree of projection less than the length of the radially open slot. The pin will prevent rotation of the two connector members by engagement of the pin with the walls of the slot. A pry tool can be used to abut the end of the pin in the slot to push it back against the spring and out of the open slot to allow rotation of the key member with respect to the bayonet slot member.
While the use of an axially projecting pin secondary lock overcomes many of the problems associated with unintentional disconnection of the connector set, it would be an improvement in the art to provide an alternative secondary locking member.
This invention provides a secondary locking mechanism for use in connection with a bayonet slot primary locking mechanism in a connector set having male and female connector members. The second locking mechanism consists of a spring ring carried by one of the members has at least one locking pin which is biased to a locking position by integrally formed spring arm section of the ring. The ring is positioned interior of a rotatable and limited actually moveable collar which is connected to and carried by the member carrying the spring ring. The collar has a locking pin receiving opening therein which the spring biased pin can snap into when the collar is in one rotational position. Movement of the pin out of the locking opening will allow the collar to be rotated to a second position circumferentially spaced from the locking position. The rotation of the collar from the locking position to the secondary position and from the secondary position to the locking position will cause the collar to undergo an axial movement.
A bayonet slot formed in the spring ring carrying member is a retrograde axial movement type slot where a key carrying member must first be inserted into the slot to a first axial position then rotated and is thereafter able to move away from the first axial position in a retrograde axial movement. Rotation of the collar causes an end face of the collar to engage an end face of the member carrying the locking key key and rotation of the collar to the locked position will force axial movement of the key carrying connector member to position the key in the bayonet slot at a point where it cannot rotate it back to the entrance slot of the bayonet slot without undergoing an axial movement which is prevented by the axial positioning of the collar. The collar will be retained in that axial position by the engagement of the spring locking pin and the collar's pin receiving opening.
The collar is provided with an access opening, which may be formed as a part of the pin receiving opening into which a tool may be inserted to push the spring pin out of the collar opening and to thereby allow rotation of the collar to occur. Upon rotation of the collar from the locked position to the second position, it will be permitted to move axially away from the opposing member of the connector set thereby allowing the opposing member and its associated key to be moved in the bayonet slot to a position where it can be rotated for disconnection.
In an embodiment of the invention the spring ring is non rotatably carried by the bayonet slot providing member and has a radially moveable locking pin positioned at the end of a cantilevered spring arm formed integrally with the locking ring, the spring arm extending in a circumferential direction. The collar has a corresponding radial opening on an inner face thereof into which the pins can project.
In an embodiment of the invention two diametrically opposed locking pins are provided, which may index into two diametrically opposed collar openings which extend into an inner diameter wall of the collar.
In an embodiment of the invention the spring ring has at least two thicknesses in the axial direction and the collar has an axial end face which has, on its inner surface, a spring ring engaging portion which will position the collar in one axial position when rotated to the locked position and which will allow positioning of the collar in a second axial position when rotated to the unlocked second position, the collar being rotatably and axially moveably carried by the connector member with the connector member having a slot into which inner diameter tabs of the collar project preventing removal of the collar member.
In an embodiment of the invention a hinged tool is provided having circuit arms dimensioned to straddle the collar, the arms having inwardly directed projections receivable in openings in the collar to push the spring pins out of the collar's spring pin openings.
Other features and objects of this invention will be apparent to those skilled in the art from the following description of a preferred embodiment.
As shown in
To maintain the members 11 and 12 in contact a bayonet connection is provided. Member 12 is provided with an outer diameter slot 19 having an axially extending entry slot 22 which is relatively circumferentially narrow and which terminates in a circumferentially wider bayonet slot base portion 23. A key 24 is affixed to the inner diameter wall 16a of opening 16 and is dimensioned to be received in the entry slot 22 of bayonet slot 19. The bayonet slot 19, 22, 23 functions along with the key 24 to provide for retrograde motion between the members 11 and 12 during rotation of the key 24 fully into the bayonet slot portion 23. Although there are many known ways of providing for such retrograde motion, the preferred embodiment utilizes a metal pin 30 which projects into the slot area 23 from its forward wall 23a. A corresponding pin 31 associated with key 24 and projects beyond the innermost end 24a of key 24. The two pins 30 and 31 therefore engage each other during rotation of the key within the slot 23 causing the member 11 to move further into joined position with member 12 then would be required by simply engaging the end surface 24a of the key with the end surface 23a of the bayonet slot section 23. After the pin 31 has moved circumferentially past pin 30, the member 11 can then be backed partially away from member 12 until such time as the pin 31 contacts the surface 23a. The dimensioning of the pins may be chosen as desired but will have a sufficient projection beyond their respective associated surfaces, the wall 23a for pin 30 and the end 24a of key 24 for pin 31 so as to allow a sufficient degree of retrograde movement for the secondary locking purposes as hereinafter described. As will be understood from the further description, when the pin 31 is bottomed against wall 23a, the key cannot be rotated from the bayonet slot 23 to the entrance slot 22 without axial movement of the members with the member 11 moving further in the direction of the member 12.
It will be appreciated that the existence of the bayonet slot and the key 24 provides a first lock preventing separation of the members 12 and 11. When the key 24 has been rotated into the section 23 of the slot 19, axial separation movement of the members is prevented by bottoming of the key against the wall 23a. Thus, in order to separate the members 11 and 12, the members must be rotated with respect to one another to align the key 24 with the entry slot 22.
As is shown in
Although a substantially L-shaped bayonet slot has been shown, except for the protrusion of the pin 30, it will be understood that an angled bayonet slot may be utilized, particularly one where the portion of the circumferentially extending bayonet portion 23 from the entrance slot to the pin is angled axially towards the main body of the connector member 12. Use of such an angled bayonet slot will cause the member 11 to move further into complete seated engagement with respect to member 12 during the twisting operation. Such angled bayonet slots are well known to those skilled in the art.
As shown best in
A groove 56 is provided in the member 12 on the side of the face 52 opposite the housing extension 18. Thus, the face 52 is formed as the front face of a circumferential ring 57 extending radially outwardly from the housing extension 18 and radially outwardly from the bottom of the groove 56. The ring 57, which is an integral portion of the housing 12, is provided with openings 60 open to the face 52 which are dimensioned to receive projections 61 on a back surface of the spring ring 50. Thus, with the projections 61, which are shown as round pins, received in the openings 60, which are shown as pinholes, the spring ring 50 will be carried against the face 52 and will not be rotatable with respect to the member 12. Preferably two or more pins 61 and associated pinholes 60 are provided circumferentially spaced from one another. The spring ring 50 will be fixedly carried by the ring 57. Other methods of rotationally restrictive attachment of the spring ring 50 to the member 12 may also be utilized, such as, for example, adhesives and bolts.
The collar 51 is received over the ring 57 and spring ring 50 and has an inner diameter 70 approximately equal to the outer diameter of the ring 57. Projections or tabs 71 on the inner diameter of the collar are received in the groove 56 to retain the collar on the member 12. The tabs 71 have an axial dimension less than the axial extent 56 such that the collar is moveable axially within limits with respect to the remainder of the members 12. The limits of movement are defined by the engagement of the axial ends of the tabs 71 at the open end of the collar with the back wall 58 of the groove 56 and the engagement of the other end of the tabs 71 with the front wall of the groove formed by the backside of the ring 57.
The collar 51 is rotatable with respect to the member 12 but has an inner diameter surface 70 terminating at a reduced diameter open end wall 74. The thickness of the end wall 74 varies circumferentially and is designed to accommodate thickness variations in the spring ring 50. As shown in
The circumferential sections forming the cantilevered spring arms are axially thicker than remaining portions of the spring ring extending between stops 90 and the points 82, 83 of the ends of the cantilevered spring arms 80, 81. The internal end wall of the collar 51 is dimensioned to mate with and ride against the front surfaces of the ring 50. It will therefore be seen that rotation of the collar will bring axially thicker portions of the inside face of the collar end wall into engagement with the transition points 82 and 83 which are provided with sloped surfaces 92 and 93. Further rotation of the collar will therefore cause the collar to move axially away from the back wall 58 of the groove 56 and towards the end wall 53 of the bayonet slot. Rotation of the collar will be stopped by abutment with the raised bosses 90. At that point, the spring projections 84, 85 at the ends of the spring fingers will snap into correspondingly configured openings 100 extending into or through the skirt 101 of the collar 51, it being understood that the inner diameter wall 70 of the collar will have kept the spring fingers in a compressed condition until aligned with the openings 100. With the spring finger projections extending into the opening 100, the collar will be locked against further rotational movement.
During the rotation from the unlocked second position to the locked first position, the axial movement of the collar 51 will bring it's face 74 into contact with the face 15 of member 11 and will force member 11 away from member 12. The extent of movement will be such as to cause the pins 30 and 31 to overlap each other in an axial direction.
If, at the time the collar 51 is rotated to the locked position with the projections at the ends of the spring fingers extending into the openings 100, and the key 24 has been rotated to the locked position within the area 23 of the bayonet slot, the axial force exhorted by the collar during the rotation to the locked position will be sufficient to have moved the pin 31 sufficiently close to the back wall 23a so as to cause an interference position will respect to the pins 30, 31.
In this position the member 11 cannot be rotated with respect to the member 12 sufficiently to align the key 24 with slot 22 thereby allowing separation of the connector members. The member 11 cannot be moved axially towards the member 12 sufficient to eliminate the axial overlap of the pin by reason of the abutment of the face 74 of the collar 51 with the end 15 of the shroud 14.
This same resilient ring compression technique may be used with different shapes of bayonet locks, and the use of pins 31 is not required where the keys 24, 40 themselves can be urged into a short return leg of an L-shaped bayonet slot. The resilient ring will thus be seen to have the ability to work in cooperation with the axial movement of the face collar 74 and its engagement with the face 15 of member 11 to maintain the members 11 and 12 in their locked position even without engagement of the projections 84, 85. In this embodiment, the first lock can be secured against accidental release by the use of the resilient ring even if the collar 51 has not been positioned to activate the secondary lock.
By depressing the spring fingers 80, 81 to allow the projection 84, 85 to be free of the opening 100, the collar 51 can be rotated, for example in the clockwise direction in
Although the preferred embodiment utilizes Varying thicknesses of the spring ring and of the inside surface of the front wall 74 of the collar to force axial movement of the collar, it will be readily appreciated that other structures may be utilized. For example, the collar may be in threaded engagement with threads on the outer diameter of the ring 57, which may have a greater axial extent, such that rotation of the collar with respect to the member 12 will cause axial movement by reason of the engagement with threads. It will also be appreciated that within the embodiment shown the sloped surfaces 92, 93 will generally mate with similarly sloped surfaces formed into the inner diameter wall of the collar and that the surfaces will act together as camming surfaces converting a portion of the rotational force being exerted against the collar into an axial force. The slope may be chosen to provide the desired axial force to circumferential turning force ratio, it being recognized that once the male and female members are in plug and socket seated condition, the frictional engagement between the plug and socket will resist axial movement of the two members.
A tool is provided for depressing the pin projections in the openings 100. A tool specifically adapted for that purpose is shown in
As will be readily apparent to those skilled in the art, modifications of this structure can be provided. For example, the locking pins projecting from the end of the cantilevered spring arms could extend axially and the spring arms be formed axially of the spring ring rather than circumferentially. In that instance the openings 100 would be placed in the front face 74 of the collar in a position radially outwardly of the contact with the skirt 14. The remaining features of preventing axial movement and allowing axial movement of the collar while engaging the face 15 of the shroud 14 can still be retained such that the secondary lock acts by preventing axial movement of the members with respect to one another.
Other modifications will also be available to persons of ordinary skill in the art. Although I have set forth my invention in connection with a preferred embodiment, it will be recognized that that is only one possible construction and that others may wish to use my invention in different forms, employing different materials or modified features.
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Number | Date | Country | |
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20090163066 A1 | Jun 2009 | US |