US2141953A - Crossing gate structure - Google Patents

Description

Dec. 27, 1938. H. F. HAWES 2,141,953

CROSSING GATE STRUCTURE Filed May 14, 1936 2 Sheets-Sheet 1 INVENTdR. Henry E Hawe's ATTORNEYS;

Dec. 27, 1938. H, w s 2,141,953

CROSSING GATE STRUCTURE Filed May 14, 1936 2 SheetsSheet 2 Ill 54 1. 1. III/11' 7 IIIIIIIIIIIIIA b\ I 27 INVENTOR. +4 Hem E Hawes BY Ma. W

A TTQRNEYS.

Patented Dec. 27, 1938 UNITED STATES PATENT OFFECE CROSSING GATE STRUCTURE Application May 14, 1936, Serial No. 79,728

4 Claims.

Conventional crossing gate structures, which are employed at railroad crossings to stop highway traffic during the approach of a train, usually comprise a hollow standard, a hollow head rotationally mounted on the upper end of the standard for limited horizontal movement out of its normal position, a gate pivotally supported by the head for vertical movement into and out of operative position and gate operating mechanism for moving the gate vertically while at the same time permitting horizontal rotation of the head. One type of gate operating mechanism heretofore proposed includes an oil jack N having a stationary part or cylinder mounted L] on the standard and a gate moving part or piston arranged within the cylinder, the piston being connected by some suitable mechanism to the gate operating shaft in the head. The present invention is directed to this type of gate operating mechanism.

The principal objects of the invention are to provide a novel form of piston cylinder structure and a novel arrangement thereof.

Another object is to simplify this type of struc- 'ture and produce reductions both in the important space occupied by it and in its cost of manufacture.

A gate structure embodying my invention is illustrated in the accompanying drawings, with the parts in the gate raised position, as follows:

Figure 1 is a top plan View of the gate housing with the gate arm broken;

Figures 2 and 3 are sections taken respectively through lines 22 and 33 of Figure 1 but showing the operating mechanism within the housing in elevation;

Figure 4 is a section taken along line 4-4 of Figure 3;

Figure 5 is a side elevation of an alternative 40 form of piston cylinder structure;

Figure 6 is a top plan view thereof;

Figure 7 is a section along line 11 of Figure 6;

I Figure 8 is a section along line 8-8 of Figure 7;

In the embodiment illustrated a hollow standard I having suitable doors la, a hollow head 2 mounted on the upper end of the standard and provided with a removable cap 3, a horizontal gate shaft 4 extending transversely through the head, and a gate 5 fixed to the outer ends of the shaft, all are shown in conventional relationship. The shaft 4 is arranged on the head 2 for pivotal movement about the horizontal axis of the shaft to rock the gate vertically into and out of the operative gate position while the head 2 is arranged on the standard I for pivotal movement about the vertical axis of the head to rock the gate horizontally into and out of the normal vertical operating plane of the gate. The rotational mounting of the head is effected through a series of irregularly spaced rollers 6 which are positioned on the standard to engage an overlying surface of the head. In the normal position of the head the irregularly spaced rollers extend into similarly spaced recesses l in the overlying head surface. These recesses cause the head to be elevated when it moves out of its normal position while the irregular spacing of the rollers and recesses is such that the head remains elevated as long as it remains out of its normal position. The head preferably is intended to swing out of its normal position in one direction only, that direction being such as to carry the gate away from the tracks. Consequently to prevent movement of the head in the opposite direction out of its normal position, the head and standard are provided with cooperating stop lugs. As previously mentioned the gate operating mechanism herein contemplated is of the jack or piston-cylinder type wherein the movement of a piston is used to efiect the vertical movement of the gate into and out of its operative position. Heretofore the cylinder has been mounted on the standard where it not only occupies space within the standard which might otherwise be devoted to important uses but, to accommodate horizontal rotation of the head, requires the use either of a horizontally rotatable piston placed in the vertical axis of the head or of other means for permitting the necessary relative movement between the cylinder and the head. In accordance with my invention the cylinder is fixedly mounted on the head thus not only increasing the usable space in the standard but at the same time permitting simplification of the operating structure due to the elimination of relative movement between the cylinder and head and to the obtainment of greater compactness.

While the cylinder may be of any suitable type and connected in any suitable way to the gate shaft 4, I prefer a construction of the novel character shown wherein the cylinder, viewed in side elevation, is of general fan shape. This cylinder, indicated generally by the numeral It, comprises a pair of parallel fan shaped side walls H which are secured to, and transversely spaced by, end members comprising a peripheral end member [2 and an apex end member l3. The apex end member l3 extends from the apex of the cylinder radially outward on both sides to the opposite ends of the peripheral end member I2 where both members are bolted to each other through suitable lugs M. The peripheral and apex end members of the cylinder are provided with supporting lugs l5 by means of which the cylinder is fixedly bolted to the side walls of the head. The side walls of the cylinder, adjacent the apex thereof, are provided with corresponding transverse openings through which the gate shaft 4 extends. The fan shaped cylinder chamber is divided into separate working chambers or compartments by a movable piston l6 which extends radially from the gate shaft 4 outwardly to the peripheral end wall, the apex end of the piston being fixedly secured to the gate shaft. It will thus be apparent that as oil is forced into the lower chamber of the cylinder and withdrawn from the upper, the piston will be forced to move pivotally upward from one end of the cylinder to the other and, in so moving, will rock the gate shaft 4 to the gate down position while the reverse action will raise the gate. Suitable adjustment screws I? are mounted in each radial end wall to permit adjustment of the limits of piston movement.

While the remainder of the structure illustrated, which includes the oil circulating part of the gate operating mechanism, forms no part of my invention a brief reference thereto will perhaps serve to clarify the construction and operation of the gate as a whole. It will be understood, of course, that any suitable fluid system may be used in operating the piston. In the system shown a motor M is used to drive a pump P in one direction only. The supply side l8 and return side IQ of the pump are connected to each other through a suitable relief valve 26 which permits a flow of oil from the supply side directly to the return side when the oil pressure increases to a predetermined limit so as to limit the force exerted by the gate should it encounter an obstruction when raised or lowered. The supply side l8 and return side IQ of the pump are also connected to a four-way valve V which in one position connects the supply side l8 of the pump to a pipe |8a leading to the upper chamber of the cylinder and the return side of the pump to apipe i9a leading to the lower chamber of the cylinder. In its other position, the valve reverses these connections. The four-way valve may be operated in any suitable manner. As illustrated it is connected to and operated by a solenoid S which moves from one position to another, when a train enters theprotected block, and returns when the train leaves such block.

The pipe connections Mia and |9a from the valve V to the cylinder chambers are separately extended upwardly to and connected with a common reservoir 2| mounted on the upper side of the cylinder l9. Each of these pipe extensions contain check valves which permit oil to flow from the reservoir into the oil system but prevent a reverse flow whereby the oil system is maintained at its maximum level at all times. The entire oil system including motor and pump preferably is mounted upon the head so as to rotate therewith when the head is horizontally turned. To this end the motor and pump are directly mounted upon a U shaped bracket 22 which depends from the lower end of the head downwardly into the standard. The operation of the motor may be controlled through any suitable control system. In this connection it may be noted that cylinder It! carries a motor up limit switch 23, which is opened only in the up position of the gate by an arm 23a on shaft 4, and a motor down limit switch 24 which is opened only in the down position of the gate by the arm 240, on shaft 4. It should also be understood that any suitable mechanism (not shown) may be employed to effect the return of the head to its normal position once it has been horizontally rotated therefrom.

An alternative head supported jack or pistoncylinder structure for operating the gate 5 through shaft 4 is shown in Figures 5 to 8 inclusive. In this embodiment upper and lower cylinders are respectively provided with separate pistons connected to each other by an intermediate piston rod'or rack which is geared to the shaft. The intermediate or piston rod space may be left open but, as shown, is preferably arranged in the form of a closed chamber through which the shaft passes whereby the gearing may be operated in a bath of oil. Accordingly the structure comprises a vertical casing 25 having upper and lower cylindrical working chambers separated by a relatively wider intermediate chamber which extends laterally outward. The outer ends of the upper, intermediate and lower chambers are all closed by removable caps 26. This cylinder is supported on the head 2 through the agency of suitable securing lugs 21. The upper and lower chambers respectively contain piston heads 28a and 2811. These pistons are secured to each other by a piston rod 29' which is made in the form of a rack having teeth 30. The cylinder is provided with transverse openings to receive shaft' l which passes through the intermediate chamber at one side of the piston rod 29. The shaft carries within the intermediate compartment of the cylinder'a pinion 31 having teeth meshing with the teeth 30' of the rack.

The upper and lower chambers are connected by suitable pipes to the four-way valve V and such pipes are likewise provided with extensions leading to a reservoir 2!. As will be obvious the forcing' of oil into the lower chamber and the withdrawal of oil from the upper chamber will cause the rack to be moved upwardly thereby rocking the shaft to its gate down position while the reverse action will rock it back to the gate up position.

Having described my invention, I claim:

1. A crossing gate structure comprising a standard, a hollow head rotatably mounted on said standard, a gate shaft mounted on said head for movement between operative and inoperative positions, a cylinder mounted on saidhead, a movable piston in said cylinder, means connecting the piston to the shaft, said means comprising a rack carried by the piston and a gear mounted on the-shaft, and means for operating said piston to move said shaft.

2. A- crossing gate structure comprising a standard, thereon, a gate shaft mounted on said head for movement between operative and inoperativepositions, a cylinder supported bysaid head, said cylinder having a pair ofspaced working chambers, a pistonin each chamber, a piston rod connecting said pistons to each other, a rack and gear connection between said pistons and said shaft comprising a-rack fixedly connected to for movement with the pistons and a gear on the shaft and meansfor operating said pistons. to move? said shaft".

3. A crossing gate structure comprising a a hollow head rotatably mountedstandard, a hollow head rotatably mounted on said standard, a gate shaft mounted on said head for movement between operative and inoperative positions, a cylinder mounted on said head, said cylinder having its interior divided into a central chamber and a working chamber On either side of said central chamber and also having an opening in the central chamber through which the shaft passes, a piston for each working chamher, a, piston rod connecting said pistons to each other, a rack and gear connection in the central chamber between the shaft and piston rod, and means for operating said pistons simultaneously to move said shaft.

4. A crossing gate structure comprising a standard, a hollow head rotatably mounted thereon, a gate shaft mounted on said head for movement between operative and inoperative positions, a cylinder supported by said head, said cylinder having a pair of spaced working chambers, a piston in each chamber, a piston rod connecting the said pistons to each other, means connecting said piston rod to said shaft, said means comprising a member connected at one end to the shaft for angular movement therewith and connected at its other end to said piston rod, and means for operating said pistons to move said member angularly and thereby move said shaft.

7 HENRY F, HAWES.

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