US1238163A - Automatic switch. - Google Patents

Description

F. A. LUNDQUIST. AUTOMATIC SWITCH.

APPLICATION FILED DEC. 2. 1916.

1 ,238, 1 63 Patented Aug. 28, 1917.

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FRANK A. LUNDQUIST, OF NEW YORK, N. Y., ASSIGNOR TO WESTERN ELECTRIC COM- IPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

AUTOMATIC SWITCH.

Specification of Letters Patent.

Patented Au 28, 1917.

Application filed December 2, 1916. Serial No. 134,574.

To all whom it may concern:

Be it known that I. FRANK A. LUND- UIST, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Automatic Switches, of which the following is av full, clear, concise, and exact description.

This invention relates to automatic switches of the gravity operated type for use in telephone exchanges.

The object of the invention is to pro vide a. switch of compact'construction for rapidly connecting a subscribers line to an idle trunk line leading to a selector'switch or to an operators position.

A feature of the invention is the positioning of cross bars to indicate the idle or busy condition of trunk lines.

lVhile the principles of the invention are shown herein as applied to a line switch, they may be readily applied to a line finder by those skilled in the art.

In the drawings, Figure 1 shows a front elevation of the switch with operating circuits; Fig. 2 is a perspective view of the brushes, showing their connection to the subscribers line; and Fig. "3 is aplan view of a cross bar.

The switch units are arranged to be mounted in a row on a frame 6 before a contact panel 9. A brush carriage 7 and a rack 8 are slidably mounted on a ribbon 5 which is held at either end to the frame 6. The brush carriage and the rack are normally held together by a spring 11, one end of which is secured to the upper end of the rack 8, the "other end being secured to the upper end of the carriage 7. A stepping magnet SM is provided with an armature 12, pivoted at 46, which has pivoted at its left end a two-armed pawl 13. A spring 45 normally holds the pawl 13 in engagement with a pin 14 on the frame. A twoarmed pawl 15, pivoted "to the frame, nor-- mally engages the teeth 16-of the rack '8, but when the magnet SM is energized, pawl 13 engages jaw 17 on pawl 15, retracting the pawl and allowing the rack and brush carriage to fall. A bell-crank lever 20, pivoted at 4.7, is normally held by an arm 21 on the rack 8, and holds the contact springs 18 open and contacts 19 closed The lever 20 will stay in normal position after the removal of arm 21 when the energization of relay SM causes'the arm 23 of pawl 13 to engage a hook 22 at the lower end of the lever. Upon the denergization of relay SM, however, spring 24: will pull the arm of lever 20 against a stop 48. When lever 20 is in this position, the energization of relay SM causes'the pawl 13to engage the teeth 16 on the rack 8, and consequently the raising of the rack.

A stop member 25 is provided adjacent and associated with each pair of multiple contact strips 49 in the contact panel 9. The stop members 25 are mounted in any convenient manner so as to permit rotation through a small. arc and are movable longitudinally. Each stop member is provided with projecting rods 26 as will be clearly seen in Fig. 3, one red being provided corresponding to each set of contacts 10. A pin 28 is mounted near the end of each stop member. A. spring 26 at the end of each stop member tends to draw the stop member to the right, but is normally prevented from doing so by the engagement of pin 28 with a plate 27 which is mounted on the frame.

A gooseneck-shaped arm 29 is pivotedto the yoke 30 which is carried by the brush carriage 7. At the lower end of the arm 29 a hook 31 is provided, and is so placed that it will engage one of the projections 26 on the first stop member 25 which is in normal position when the brush carriage 7 is allowed to fall. A pair of brushes 32, 33 are insulatedly mounted at the upper end of the arm 29, and are so positioned that when said arm is rotated inrian anti-clockwise direction, after the hook 31 has engaged a rod 26 and the stop member 25 has been moved to the right, the brush .32 will make contact with the upper one of a set 10 of contacts and the brush 33 with the lower one of said set. Two metal strips 34 and 35 are insu-latedly mounted on a hinge 36 which is held at either end in the frame 6. The brush 32 will make contact with the strip 35 and the brush 33 with the strip '31 at the same time that contact is made with contacts 10, as will be clearly seen in Fig. 2,. When the brushes engage these strips, the strips turn on the hinge 36 so as to open the off-normal contact ON, which is located near the upper end of the strip 34s Further details of construction will be understood from the following description of the operation of the switch.

When the subscriber at the substation indicated. at A removes the receiver from its hook, he completes an energizing circuit for the relay LR from grounded battery, through the winding of the relay LR, wire 37, off-normal contact ON, wire 2, substa tion A, wire 1, wire 38, through the retardation coil BC to ground. The consequent energization of the relay LR completes a circuit from grounded battery, armature and front contact of relay LR, wire 39, back contact and armature 12 of relay SM, through the winding of the magnet SM to ground. The consequent energization of the magnet SM breaks this circuit at the back contact of the armature of SM, but closes the wrings 50, thus establishing a holding circuit for said magnet from battery, armature and front contact of relay LR, wire 39, springs 50, contact spring 19, through the winding of the magnet SM to ground. The pulling up of armature 12 of magnet SM causes the pawl 13 to engage the pawl 15, and release the rack 8 and brush carriage 7 in the manner previously described. The fall of the carriage and rack is arrested by the engagement of the hook 31 with a rod 26 on the stop member associated with the first idle trunk line encountered. This engagement turns the stop member 25 so as to allow the pin 28 to ride over the edge of the plate 27, and to close contact springs 40 and 41. The spring 26 now pulls the stop member 25 to the right until its motion is limited by the engagement of a lug 42 on the stop member with a pawl 43 carried on the armature of the release magnet Rel. This engagement completes a circuit for the slow acting relay 44 from battery, through the winding of the relay 44, contact springs 40, wire 3, upper contact 10, brush 33, strip 34, wire 2, substation A, wire 1, wire 38, through the coil BC to ground. The subscriber at the station A is now connected through wire 1, strip 35, brush 32, contact 10, wire 4, and through wire 2, strip 34, brush 33, contact 10 and wire 3 either to a first selector or to an operator, according as the exchange is automatic or semi-automatic.

When the stop member 25 was drawn to the right, the engagement of the brushes with the metal strips 32 and 33 opened the contact ON, thereby breaking the circuit for the relay LR which retracted its armature. In falling back the armature of the relay LR broke the circuit holding up the magnet SM which thereupon retracted its armature. The removal of the arm 23 of pawl 13 from engagement with hook 222 allowed lever 20 to turn in an anti-clockwise direction so that contact springs 18 close and springs 19 open. A circuit is thereupon completed from grounded battery, armature and back contact of relay LR, spring 18, wire 39, back contact and armature of magnet SM, through the winding of the magnet SM to ground. The consequent energization of the magnet SM causes the engagement of a tooth in the racks 8 by the pawl 13, and lifts the rack one step.

Since the circuit for the magnet SM is broken at the back contact of its armature, when it is energized it will intermittently fall back and pull up again until the rack S has been stepped back to normal position, at which time the arm 21, by raising lever 20, opens contact springs 18 and permanently breaks the circuit for SM. The brush carriage 7 is not returned to normal, however, since the rod 26 holds hook 31 as long as stop member 25 is in off-normal position.

At the close of the conversation the subscriber at A breaks at his switchhook the previously traced circuit for the relay 44, which thereupon retracts its armature and closes a circuit for the release magnet from grounded battery, armature and contact of relay 44, contact springs 41, through the winding of the release magnet Rel. to ground. The consequent attraction of the armature of the magnet Rel. forces pawl 43 and lug 42 to the left until the pin 28 has moved beyond the vertical edge of the plate 27, at which time stop member 25 is rotated by a spring (not shown) until the pin 28 engages said edge. When the stop member 25 moves to the left, the rod 26, pressing against the left jaw of hook 31, frees arm 29 so that the spring 11 elevates brush carriage 7 to normal. The yoke 30 is arranged to allow the lower end of the arm 21 to ride over such rods 26 as may lie in its path during restoration. The removal of the brushes from engagement with the strips 34 and 35 allows them to be returned to normal by a spring (not shown), and the switch is now ready for the next call.

What is claimed is:

1. In an automatic switch, a plurality of terminal strips, a gravity operated brush to cooperate therewith, means for releasing said brush, and a plurality of longitudinally movable stop members extending across the faces of said terminal strips arranged to arrest the movement of a falling brush.

2. In an automatic switch, a plurality of terminal strips, a gravity operated brush to coiiperate therewith, means for releasing said brush, a plurality of longitudinally movable stop members extending across the faces of said terminal strips arranged to arrest the movement of a falling brush, and means responsive to the engagement of a falling brush with a stop member for moving said stop member longitudinally from the path of subsequently falling brushes.

in an automatic switch, sets of multiple line terminals, a longitudinally movable stop member associated with each set of said line terminals, means for maintaining said stop members in a definite position when the associated line terminals are in a certain electrical condition, brushes arranged to travel over and make contact with said line terminals, and mechanical means responsive to the position of said stop members for controlling said brushes.

i. In an automatic switch, sets of multiple line terminals, a longitudinally movable stop member associated with each set of said line terminals, means for maintaining said stop members in a definite position when associated line terminals are in a certain electrical condition, brushes arranged to travel over and make contact with said line terminals, members arranged to engage any one of said stop members which is in normal position, and means responsive to such engagement for longitudinally displacing said engaged member.

5. In an automatic switch, sets of multiple line terminals, a longitudinally movable stop member associated with each set of said line terminals, means to maintain said stop members in a normal or an actuated position corresponding to the idle or busy condition of said associated line terminals a brush carriage, brushes on said carriage arranged to travel over and make contact with said line terminals, an engaging member carried by said brush carriage arranged to engage the first one of said stop members which is encountered in normal position during the travel of said carriage, means for initiating the travel of said carriage. and a spring associated with each stop member for moving said stop member when engaged out of the path of movement of subsequently falling engaging members.

6. In an automatic switch, sets of multiple line terminals, a longitudinally movable stop member associated with each set of said line terminals to denote by its position the idle or busy condition of said associated line terminals, a gravity operated brush carriage, brushes on said carriage arranged to travel over and make contact with said line terminals, an engaging member carried by said brush carriage arranged to engage the first one of said stop members which is encountered in normal position during the travel of said carriage, means for initiating the travel of said carriage, and a spring associated With each stop member for moving said stop member when engaged out of the path of movement of subsequently falling engaging members and for causing said associated brushes to make contact with the selected terminals.

In witness whereof, I hereunto subscribe my name this 29th day of November A. 1)., 1916.

FRANK A. LUNDQUIST.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Yatents. Washington, I). C.

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