US1979369A - Safety gate - Google Patents

Description

NOV. 6, 1934. w w c s m ET AL 1,979,369

SAFETY GATE Filed Sept. 2, 1933 2 Sheets-Sheet 1 ill-mentors [Gilliam 11]- Bushlgg Hubert K-PE.I.IHBI" 1934- w. w. CUSHING El AL 69 SAFETY GATE Filed Sept. 2, 1935 2 Sheets-Sheet 2 hluantnrs UJllllEHl'L U]- Eushmg Hobart PLP-almar Patented Nov. 6, 1934 UNITED STATES SAFETY GATE v William Whelan Cushing and Robert Kendrick Palmer, Hamilton,.0ntario, Canada Application September 2,.1933, Serial No. 687,970

8 Claims. (01.:39-8) Our invention relates to improvements in safety gates as are used on highways at level railroad crossings, ends of movable bridges, etc., and the object of our invention is to furnish a very simple and positive gate actuating mechanism which can be constructed and installed at a comparatively low cost and which will require very little attention.

A further object of our invention is to incorporate a hydraulically actuated piston in. our gate actuating mechanism for imparting movement to the gate, and also to furnish a simple gate" locking device which will positively retain the gate in either the open or closed position and which can be released with a negligible power consumption.

Our invention consists of a gate constructed and arranged all as hereinafter more particularly described and illustrated in the accompanying drawings in which I i Fig. 1 is a plan view of the housingin which our gate mechanism is contained, showing the inner end portions of the gates supported thereby, the gates being in the downward or closed position.

Fig. 2 is a side elevational view of the gate mechanism housing showing the gates in full lines .in the up or open position, and in dotted lines in the downward position.

Fig. 3 is a vertical cross sectional view through the housing and mechanism wherein the gates are in the open position.

Fig. 4 is a similar view to Fig. 3, showing the position of thelmechanism with the gates in. the 35' closed position.

Fig. 5 is a transverse cross sectional view through the housing and mechanism, being taken through the line 55, Fig. 4.

.Fig; 6 is a horizontal-cross sectional view taken 1 ,through the upper portion of thehousing and mechanism, showing the gate supporting shafts,

and

i Fig. '7 is'a perspective view of a pair of lcam plates which we furnish as the gate lockingimeans.

uLike characters of reference indicate corre- -.sponding}parts in the different views in .the draw- -ings. i

The gate consists of the usual wooden arms-1 60 and 2 for the roadway and sidewalk respectively.

The inner end of the arm 1 is of bifurcatedform -.andis bolted to apair of' swingable members 3 carried upon the ends of a cross? shaft 4:exteriorply of the mechanism housing 5. Thewmembers are furnished with the usual counter-weights 6.

tion of the motor 25, the oil ispumped from tone end of a shaft 8 lying parallel to the shaft 4 and protruding from the housing 5. The rotatory movement of the shafts 4 and 8 swing the arms from the horizontal to vice versa.

The shafts 4 and 8 carry a pair of segmental gears 9 andIO which are keyed thereto in positions opposite one another.

The segmental gears 9 and 10 mesh with a vertically "reciprocable rack 11 having teeth upon the sides thereof with which the gears engage. The rack is formedwith a central slot 12 through which a supporting pin 13 extends, the pin being carried 'between a pair of transversely extending horizontal supporting plates 14 through which the shafts 4 and 8 freely extend. The provision of the pin 13 within the slot 12 limits the recipthe vertical positions and rocable movement of the rack and also furnishes a support for the rack when it is in the lowermost position, as illustrated in Fig. 3. The lower end of the rack is of substantially circular cross section and is formed with a bore 15 extending upwardly from its lower end to receive the upper end of a piston rod 16 which slidably protrudes thereinto. The piston rod is permitted a sliding movement'within the bore 15, and to limit such sliding movement we provide the bore portion of the rack with a pair of diametrically positioned vertical slots 17 which receive the ends of a cross pin 18 extending through the upper end of the piston rod. The piston rod has a movement in the bore limited by the movement of the pin within the slots 1'7.

The piston rod 16 protrudes from a cylinder and piston assembly 19and 20 which is suitably supported by a plurality of angles 21 extending across the lower'portion of the housing.

The cylinder 19 is filled with fluid such as oil and in order to reciprocate the piston 20, we furnish an oil pump 22 which communicates with the-upper and lower ends of the cylinder through pipes23 and 24. The pump 22is of the reversible type and .is actuated by an electric motor 25' whichis also of the reversible type and connected to the pump through the medium of a belt 26 extending over the pump and motor pulleys 27 and 28. By reversing the direction of rotaendof the cylinder to the other with the result- '105 ant actuation of the piston 20. In-order to pro vide for any over-run of the motor-afterothe piston has been moved from one. end of the-cylinder to the other, we furnish a by-pass oil pipe V 29 extending from the pipes 23 and 24 around the pump. The by-pass pipe is furnished with a hand adjusted valve 30 which permits the contained oil to leak past when a certain oil pressure has been reached, so that, if the motor 25 should continue to run after the piston has reached the end of its movement, the pumped oil will then by-pass through the pipe 29.

For locking the rack 11 at the upper and lower ends of its travel, we furnish a pair of gravity actuated cam weights 31 which are pivotally mounted upon the pin 13 upon either side of the rack and pinions. These cam weights are of the same size and form and each consists of an upper substantially vertical portion 32 formed with a horizontal land edge 33 upon its top and a slot 34 in the vicinity of its lower end, The upper end of the rack 11 is formed with two horizontally protruding lips 35, such lips being adapted to rest upon the lands 33 when the rack is in the uppermost position, and to abut against the upper faces of the slots 34 when the rack is in the lowermost position. In order to permit the rack to reciprocate, the upper ends 32 of the cam weights are swung in the direction of the arrows shown in Figs. 3 and l. For swinging the upper cam weight portions 32, we form the lower weight portions of the cam weights of enlarged size and of such dimensions that their edges 36 are of substantially V form and are engaged by the protruding ends of the cross pin 18, the apexes of the edges 36 normally lying beyond one side of the rack 11 and the major portion of the cam weights lying at the other side of the rack. The cam weights are, of course, so designed that they have sufficient clearance in their swinging movement.

The operation of our device is as follows:-

When our device is in the position illustrated in Fig. 3, the gates are open, i. e. the arms 1 and 2 are substantially vertical, the segmental gears 9 and 10 downwardly inclined and the rack 11 and piston 20 at the lower ends of their movements. When it is desired to close the gates, the current actuating the motor 25 is switched on, either manually or automatically through the approach of a train, as is the case in railroad crossing gates. The rotation of the motor actuates the pump 22 to pump oil from the upper end'of the cylinder through the pipes 23 and 24 into the lower end of the cylinder and move the piston 20 and the piston rod 16 upwardly. As the cross pin 18 extending through the piston rod and the lower portion of the rack is at the lower ends of the slots 17, the piston rod is permitted an initial free upward movement without a corresponding movement of the rack. When this initial movement of the piston rod occurs, the pin 18, the ends of which bear against the V edges 36 of the cam weights, moves upwardly and in bearing against and moving along such V edges swings the lower portions of the cam weights about the supporting pin 13 in a clockwise direction, as shown in Figs. 3 and 4, with the resultant swinging movement of the upper ends 32 of the cam weights, as shown by the arrows. Before the cam weights are moved the lips 35 upon the upper end of the rack 11 are contained within the cam weight slots 34 and the rack locked against movement. When the upper ends 32 of the cam weights are swung the slots 34 become disengaged from the lips and when the cross pin 18 reaches the upper end of the slots 17 the rack 11 is free to move upwardly with the piston rod.

As the ends of the pin 18 in their upward movement pass around the apexes of the cam edges 36,

the cam weights have a return swing in a counterclockwise direction under their own weight, and by the time the rack has reached the upper end of its stroke, as illustrated in Fig. 4, the landings 33 at the upper ends 32 of the cam weights swing into a position beneath the rack lips 35, thus retaining the rack against downward movement and holding the gears 9 and 10 in the up position and the gates in the horizontal or closed position.

When the gates are to be opened, the motor 25 is rotated in the reverse direction, causing the fluid to pass from the lower to the upper part of the cylinder 19 with the resultant downward movement of the piston 20, piston rod 16 and cross pin 18 within the slot 17. As previously explained, the outer ends of the cross pin 18 ride against the v edges 36 of the cam weights, so that when the pin travels downwardly in conjunction with the piston rod its downward movement causes the cam weights to again swing in a clockwise dire ction'wherein the lands 33 swing from underneath the rack lips 35. When the pin 18 reaches the bottoms of the slots 17 the lands 33 of the cam weights have moved completely from underneath the lips 35, and the further downward movement of the piston rod pulls the rack downwardly, thus causing the segmental gears 9 and 10 to swing in a clockwise direction with the consequent partial rotation of the shafts 4 and 8 and swinging movement of the gates into the open position as shown in Fig. 3.

It will be apparent that the provision of the cam weights engaging the lips on the rack provides a positive means for retaining the rack in either the upward or downward position as the case may be and that through the provision of the free reciprocable movement between the piston rod and the rack during the initial stages of operation for the purpose of swinging the cam weights out of the rack engaging position that we have provided a very simple and positive mechanism. If at any time the pump mechanism should go out of order, or the electrical current supply be cut off, and it is desired to use the gates, the housing door may be opened, the cam weights manually swung into the unlocked position and the gates moved upwardly or downwardly by hand. Although we have shown a particular embodiment of our invention, it is to be understood that we can at any time make any changes that we may see fit without departing from the spirit of our invention as set forth in the appended claims.

What we claim as our invention is:

1. In a level crossing gate for railroads and the like incorporating a vertically swingable gate arm, the combination with a piston, piston rod and cylinder assembly constituting the arm swinging power means and a reciprocable element slidably coupled to the piston rod and geared to the swingable arm, of a swingably mounted cam member swung by the piston rod in its travel and adapted to engage and lock the reciprocable element at the ends of its stroke, and a pin projecting from the piston rod and slidably contained within a slot in the reciprocable element to constitute the slidable coupling between the piston rod and the reciprocable element and also adapted to engage the cam face of the cam member.

2. In a level crossing gate for railroads and the like incorporating a vertically swingable gate arm, the combination with a piston, piston rod and cylinder assembly constituting the arm swinging power means and a reciprocable element slidably coupled to the piston rod and geared to the swingable arm, of a swingably mounted cam member swung by the piston rod in its travel and adapted to engage and lock the reciprocable element at the ends of its stroke, and a pin projecting from the portion of the piston rod contained within the bore into a slot within the bore portion of the reciprocable element to constitute the slidable coupling between the piston rod and the reciprocable element and also adapted to engage the cam face of the cam member.

3. In a level crossing gate for railroads and the like incorporating a vertically swingable gate arm, the combination with a piston, piston rod and cylinder assembly constituting the arm swinging power means and a slotted reciprocable element slidably coupled to the piston rod and geared to the swingable arm, of a swingably mounted cam member swung by the piston rod in its travel and adapted to engage and lock the reciprocable element at the ends of its stroke, and a pinprojecting through the slot in the reciprocable member to limit its movement and also constituting the pivotal point about which the cam member swings.

4. In a level crossing gate for railroads and the like incorporating a vertically swingable gate arm, the combination with a piston, piston rod and cylinder assembly constituting the arm swinging power means and a reciprocable element slidably coupled to the piston rod and geared to the swingable arm, of a gravity actuated swingably mounted cammember swung by the piston rod in its travel and adapted toengage and lock the reciprocable element at the ends of its stroke.

5. In a level crossing gate for railroads and the like incorporating a vertically swingable gate arm, the combination with a piston, piston rod and cylinder assembly constituting the arm swinging power means and a slotted reciprocable element slidably coupled to the piston rod and geared to the swingable arm, of a gravity actuated swingably mounted cam member swung by the piston rod in its travel and adapted to engage and lock the reciprocable element at the ends of its stroke, and a pin projecting through the slot in the reciprocable member to limit its movement and also constituting the pivotal point about which the cam member swings.

6. A level crossing gate for railroads and the like comprising a vertically swingable gate arm, a piston, piston rod and cylinder assembly constituting the arm swinging power means, a reciprocable rack substantially moving in unison with the piston rod and geared to the swingable arm, a rockable gravity actuated cam member rocked by the piston rod in its travel, and a member projecting from the rack and adapted to engage with the cam member and be releasably retained by the cam member against movement at the ends of the racks stroke.

7. A level crossing gate for railroads and the like comprising a vertically swingable gate arm, a piston, piston rod and cylinder assembly constituting the arm swinging power means, a reciprocable slotted rack substantially moving in unison with the piston rod and geared to the swingable arm, a rockable gravity actuated cam member rocked by the piston rod in its travel, a member projecting from the rack and adapted to engage with the cam member and be releasably retained by the cam member against movement at the ends of the racks stroke, and a pin projecting through the slot in the reciprocable member to limit its movement and also constituting the pivotal point about which the cam member rocks.

8. A level crossing gate for railroads and the like comprising a vertically swingable gate arm, an arm swinging reciprocable element, a gear connection between the element and the gate, gravity actuated cam means for releasably engaging the element to lock the gate both in the open and closed positions, a piston, piston rod and cylinder assembly constituting the reciprocating power means, coupling means between the piston rod and the reciprocable element, a power driven fluid pump, fluid pipes extending from the pump to the ends of the cylinder, a by-pass pipe extending between the pipes around the pump, and an adjustable fluid passage valve contained within the by-pass pipe.

WILLIAM WHELAN CUSHING. ROBERT KENDRICK PALMER.

Images