GB2544076A

GB2544076A - Adjustable driver's seat

Info

Publication number: GB2544076A
Application number: GB1519550.6A
Authority: GB
Inventors: Alfred Bell Laurence
Original assignee: CREACTIVE DESIGN (ENGINEERING) Ltd; Creactive Design (engineering) Ltd
Current assignee: CREACTIVE DESIGN (ENGINEERING) Ltd; Creactive Design (engineering) Ltd
Priority date: 2015-11-05
Filing date: 2015-11-05
Publication date: 2017-05-10
Anticipated expiration: 2035-11-05
Also published as: GB201519550D0; GB2544076B

Abstract

An adjustable driver's seat 10 for a railway vehicle has a pivotable backrest 16 mounted to a slidably adjustable seat 14 mounted to a vertically adjustable telescopic support leg 12 for engaging the floor. The pivotable seat back is mounted to the seat by a concentric bearing 130 and pneumatic hydraulic pistons 252 can provide actuation. The seat 14 is slidably adjusted on plain bearings providing low friction bearing face (142, fig 7) such as a counterpart (92, fig 7) of phosphor bronze. The plain bearing part (142, fig 7) can be in the form of a U-shaped channel into which the counterpart (92, fig 7) is guided. A toothed rocker assembly interfering with a notched channel allows adjustment in relative horizontal secured position. The vertically adjustable support leg 12 has a plain bearing interface.

Description

Adjustable Driver’s Seat

The present invention relates to an adjustable driver's seat for a railway vehicle.

The same railway vehicle will be driven by different drivers, meaning adjustment of the seat position is necessary. Adjustable driver's seats for railway vehicles are known. Commonly, the adjustment is provided in the vertical axis, to adjust the distance between the seat and the floor of the driver's cabin (seat height adjustment) and in the longitudinal axis, to adjust the distance between the seat and the dashboard of the railway vehicle (seat back and forth adjustment).

In order to maximise passenger carrying capacity, the driver's cabin may be relatively small. A further form of adjustment then may also be provided to enable the seat back rest to be hinged forwards, to allow passage behind the seat in an otherwise confined space (seat back rest hinge adjustment).

In known adjustable driver's seats, a large number of components are needed to ensure full adjustability of the seat. For example, in a known adjustable driver's seat the seat back and forth adjustment is provided by ball bearing races, the seat height adjustment is provided by ball bearing races and the seat back rest hinge adjustment is provided by a ratchet mechanism. Thus a large number of components are required to provide the requisite adjustability.

Each component has a certain tolerance. A tolerance stack is created by assembly of the multiple components. The tolerance stack may adversely affect the quality of adjustment. To mitigate this in part, shim is used. This is a time consuming and complex process. Considering a specific example, the seat height adjustment is provided by three ball bearing races arranged around a seat column. The ball bearing races are parallel to one another, running vertically. The ball bearing races comprise a tray component defining two parallel ball bearing channels and a counterpart component closing the two parallel ball bearing channels. To ensure that the tray component and the counterpart component are slidably moveable to one another, the position of the two components must be tightly controlled. Furthermore, as the seat height adjustment is provided by three ball bearing races, a total of six components must be tightly controlled.

The components used in adjustable driver's seats must undergo cyclical usage, as different drivers operate the same railway vehicle in a shift pattern. This causes wear of the components. If a component fails, the seat may no longer be fully adjustable, such that is it not possible to operate that railway vehicle. This causes delays and incurs a cost penalty to the railway operator. A further challenge faced by the adjustable driver's seat is the harsh operating environment. Railway vehicles are operated on tracks and experience a high vibration loading. This vibration is amplified by railway carriage which is mounted on the chassis. As known driver's seats are mounted on the driver's cabin floor and not directly to the chassis, the seats experience a high level of vibration as the driver's cabin floor amplifies the vibrations of the chassis. The high level of vibration also adversely effects the numerous components required to provide adjustment.

Ball bearing races are especially susceptible to wear. The single point contact of each ball bearing in a ball bearing race creates a circulate groove in the contact surface of the bearing counterpart. Over time, this groove grows such that the ball bearings rattle within the ball bearing race. This process is exacerbated when the ball bearing races are misaligned or under vibration loading.

The invention aims to provide an adjustable driver's seats which addresses one or more of the above mentioned problems.

According to the first aspect of the present invention there is provided an adjustable driver's seat for a railway vehicle, the seat comprising a floor engaging structure; a seat sliding portion; and a back rest portion; wherein the floor engaging structure has a first part and a second part, wherein the back rest portion is pivotably mounted with respect to the seat sliding portion, the back rest portion pivotably mounted on at least one concentric bearing assembly; wherein the seat sliding portion is slidably mounted with respect to the floor engaging structure, the seat sliding portion slidably mounted on at least one horizontal plain bearing assembly; and wherein the floor engaging structure is telescopic so as to vary the separation of the seat sliding portion from the first part of the floor engaging structure, the second part of the floor engaging portion being slidably mounted on at least one vertical plain bearing assembly provided on the first part.

By using plain bearings to provide both horizontal and vertical adjustment of the driver's seat, fewer components are necessary and a greater level of robustness is provided allowing the driver's seat to endure the harsh operating environment and cyclical usage required of an adjustable driver's seat suitable for use in a railway vehicle.

The seat sliding portion may be slidably mounted on two horizontal plain bearing assemblies. The floor engaging surface may be mounted on two vertical plain bearing assemblies provided on the second part of the floor engaging surface. The back rest may be pivotably mounted on two concentric bearing assemblies. The back rest may be adjusted by a hydro-pneumatic system.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying figures, in which:

Figure 1 is a perspective exploded view of the adjustable driver's seat of the present invention;

Figure 2 is a magnified view of the floor engaging structure of the adjustable driver's seat of Figure 1;

Figure 3 is a magnified view of the seat frame of the adjustable driver's seat of Figure i;

Figure 4 is a magnified view of the underside of the seat frame of the adjustable driver's seat of Figure 1;

Figure 5 is a plan view of the horizontal adjustment assembly of the adjustable driver's seat of Figure 1;

Figure 6 is a cross sectional view taken at line A-A in Figure 5;

Figure 7 is a cross sectional view taken at line B-B in Figure 5;

Figure 8 is a magnified view of the back rest portion of the adjustable driver's seat of Figure 1;

Figure 9 is a side view of the seat frame of Figure 1; and

Figure 10 is a cross-sectional view taken at line C-C of Figure 9.

With reference to Figure 1, an adjustable driver's seat 10 for a railway vehicle has a floor engaging structure 12; a seat sliding portion 14, a back rest portion 16.

Floor Engaging Structure

The floor engaging structure 12 (see Figure 2) has a floor plate 20, a square base plate 30, a cylindrical column 40, a pair of vertical plain bearings 50, concentric elements 60, a square column 70, four supports 80, a cover plate 90 and vertical adjustment handle 95.

The floor plate 20 is substantially triangular in plan, and has three recessed apertures 22, arranged substantially in each comer thereof, for receiving a fastener for connection of the floor plate 20 to a floor 8 of the driver's cabin. The floor plate 20 has four circular apertures 24 arranged in the corners of a square centrally aligned in the floor plate 20.

The cylindrical column 40 has a lower end 42 and an upper end 44. The lower end 42 terminates in the square base plate 30. The square base plate 30 has four recessed apertures 32, arranged in the comers thereof.

Attached to either lateral side of the cylindrical column 40 is a vertical plain bearing 50. The vertical plain bearings 50 have a channel 52 defining three bearing surfaces in which a counterpart plain bearing 54 sits.

The concentric elements 60 are cylindrical in form and concentrically arranged with the cylindrical column 40.

The square column 70 includes attachment apertures 72 running vertically down each lateral side. The two counterpart plain bearings 54 being attached to either lateral side by fasteners passing through the attachment apertures 72.

The supports 80 are substantially identical such that only one shall be described in detail. The supports 80 are substantially U-shaped in plan and include downwardly depending flanges 82.

The cover plate 90 is substantially rectangular in plan and includes circular apertures 92 arranged on the cover plate 90. The cover plate has a pair of horizontal bearing assemblies 140 which are fastened to the upper surface of the cover plate 90, as will be described in more detail below.

The floor engaging structure 12 is assembled as follows. The floor plate 20 is attached to the floor 8 of the driver's cabin using three fasteners passing through the three recessed apertures 22. The square base plate 30 of the cylindrical column 40 is aligned with the four circular apertures 24 in the floor plate 20. Four fasteners are passed through the four recessed apertures 32 of the square base plate 30 and the four circular apertures 24 of the floor plate 20 to attach the cylindrical column 40 to the floor plate 20.

The vertical plain bearing 50 is attached to either lateral side of the cylindrical column 40. The counterpart vertical plain bearing 54 is attached to an inner lateral surface of the square column 70 by attachment apertures 72. The square column 70 is arranged concentrically over the cylindrical column 40 so that each of the counterpart vertical plain bearings 54 run in a channel defined by the vertical plain bearings 50.

The supports 80 are attached to the square column by their downwardly depending flanges 82. The cover plate 90 is attached to the supports 80 by fasteners passing through the circular apertures 92 provided through the cover plate 90.

Vertical Adjustment

The floor engaging structure 12 is capable of vertical adjustment. In use, manipulation of a vertical adjustment handle 95 activates an air spring mounted in the cylindrical column 40 within concentric elements 60. This causes vertical movement of the square column 70 relative to the cylindrical column 40 as the counterpart plain bearing 54 slides along the channel 52 of the vertical plain bearing 50. This means that the distance between the cover plate 90 and the floor plate 20 may be varied, thus providing the vertical adjustment of the driver's seat 10.

Seat Sliding Portion

The seat sliding portion 14 has a seat frame 100, a first hinge arm 110, a second hinge arm 120, hinge mechanism features 130, and horizontal adjustment assembly 140.

The seat frame 100 (see Figures 3 and 4) is substantially rectangular in plan, having forwards, rearward and left and right sides. The seat frame 100 has an upper surface 102 and a lower surface 103. The seat frame upper and lower surfaces 102, 103 define eight lightening holes 104 therebetween. The seat frame 100 has a downwardly depending flange 106 from upper surface 102 on the forward, left and right sides, and an upwardly depending flange 108 on the rearward side. The downwardly depending flange is turned in to create lip 107 having lower surface 109.

Horizontal Adjustment

Referring to Figures 5 to 7, the horizontal bearing assemblies 140 includes a pair of horizontal plain bearings 142, each with a respective horizontal plain bearing counterpart 94. A horizontal adjustment handle 146 is also provided.

The horizontal adjustment handle 146 has a forward handle part 147 and a rearward handle part 148. The forward and rearward handle parts 147, 148 are made of steel rod. They are connected at either end by two parallel lengths of rectangular steel bar 149. The connection is made by a welded joint. The horizontal adjustment handle 146 effects the back and forth adjustment of the seat sliding portion 14 as will be described in more detail below.

The pair of horizontal plain bearings 142 are substantially similar, such that only one shall be described in detail, (see Figures 6 and 7).

The horizontal plain bearing 142 is a solid elongate member having an upper surface 152 and a lower surface 154. The upper surface 152 is attached to the lower surface 109 of the lip 107 of the downwardly depending flange 106 of the seat frame 100. The lower surface 154 defines an elongate recessed channel defining three bearing surfaces 158.

The horizontal plain bearing counterpart 94 is a solid elongate member having an upper surface 162 and a lower surface 164. The lower surface 164 is attached to an elongate notched member 166. The elongate notched member 166 is in turn attached to an elongate spacer member 168. The elongate spacer member 168 is in turn attached to the upper surface of the cover plate 90.

An elongate keeper 151 is bolted to the horizontal plain bearing 142 and substantially prevents vertical movement of the horizontal plain bearing 142 relative to the horizontal plain bearing counterpart 94.

The upper surface 162 of the horizontal plain bearing counterpart 94 opposes the lower surface 154 of the horizontal plain bearing 142, as the horizontal plain bearing counterpart 94 is located in the recessed channel. The horizontal plain bearing counterpart 94 is made of phosphor bronze. The elongate member horizontal plain bearing 142 is made of steel. The elongate member contacts and is slidably moveable with respect to the three bearing surfaces 158 of the recessed channel.

As shown best in Figure 6, a stop 169 is provided in the horizontal plain bearing 142 and projects into a cut-out in the counterpart 94, which terminates at cut-out terminations 171. The stop 169 prevents over-travel of the horizontal plain bearing 142 relative to the horizontal plain bearing counterpart 94.

Control of the horizontal adjustment assembly 140 is provided by a toothed rocker assembly 170. The toothed rocker assembly 170 has a rocker 172 and a toothed plate 174.

Adjacent the horizontal adjustment assembly 140 is the length of rectangular steel bar 149 of the horizontal adjustment handle 146. The rocker 172 is attached to the length of rectangular steel bar 149 by fasteners. The rocker 172 is pivotably mounted to an inward facing side 141 of the horizontal plain bearing 142. The elongate notched member 166 has an inward facing side. The inward facing side defines a series of the equally spaced notches 167 extending fore to aft along the elongate notched member 166. The toothed plate 174 is fastened to a lower surface of the rocker 172. The toothed plate 174 has two protrusions 175 which interlock with adjacent notches 167.

In use, the forward handle part 147 of the horizontal adjustment handle 146 is pulled upwards. The rocker 172 pivots about a pivot point extending from the inward facing side 141 of the horizontal plain bearing 142 and against a rod spring. Pivoting of the rocker 172 results in the toothed plate 174 moving downwards relative to the elongate notched member 166 so that the protrusions 175 are brought out of engagement with the notches 167, and into horizontal alignment with spacer member 168. Horizontal movement of the seat frame 100 relative to the cover plate 90 is then possible as the counterpart horizontal plain bearing 144 slides along the channel of the horizontal plain bearing 142. Release of the forward handle part 147 results in the horizontal adjustment handle 146 returning to the a rest position under the influence of the rod spring, so that the protrusions 175 interlock with adjacent notches 167 and the seat frame 100 is held fast relative to the cover plate 90.

Alternatively, if the user is positioned behind the adjustable driver's seat 10, pressing downwards on the rearward handle part 148 to overcome the rod spring has a similar effect.

Back Rest Portion

Briefly referring back to Figures 3 and 4, the first and second hinge arms 110, 120 are substantially identical such that only the first hinge arm 110 shall be described in detail. The first hinge arm 110 is planar, defining a lower portion 111 and an upper portion 112. The upper portion defines circular bore 113 with six equally spaced smaller circular bores 114 arranged around the circumference of the circular bore 113. A slot 115 is provided on the lower side of the bores 113, 114.

The back rest portion 16 (see Figure 8) has seat back 200, a first hinge arm 210, a second hinge arm 220 and hinge mechanism features 250.

The seat back 200 is substantially rectangular in plan and of bent sheet construction, in a similar manner to seat frame 100. The seat back 200 has lateral flanges 206.

The first and second hinge arms 210, 220 are substantially identical such that only the first hinge arm shall be described in detail. The first hinge arm 210 is planar, defining a lower portion 211 and an upper portion 212. The lower portion 211 defines a circular bore 213 with six equally spaced smaller circular bores 214 arranged around the circumference of the circular bore 213.

The hinge mechanism features 250 include a pair of brackets 251, a pair of pneumatic hydraulic pistons 252, a pair of actuating valves 253, a pair of actuating cylinders 254, actuating arm 255, and a hinge adjustment handle 260.

The back rest portion 16 is assembled by joining the upper portion 212 of the first and second attachment arms 210, 220 to respective lateral flanges 206, so that the first and second hinge arms 210, 220 extend downwardly from the seat back 200.

The back rest portion 16 is assembled to the seat sliding portion 14 by aligning the circular bores 113 of the first and second hinge arms 110, 120 of the seat frame 100 with the circular bores 213 of the first and second hinge arms 210, 220 of the seat frame 200. The hinge mechanism features 130 of the seat sliding portion 14 are then attached to the respective circular bores 113, 213 to allow pivoting of the back rest portion 16 relative to the seat sliding portion 14. A circular plain bearing 222 is attached to the seat frame 100 with a counterpart seat base bearing portion 224 with a spigot counterpart circular plain bearing 225 located inside. Thus the hinge mechanism features 130 are arranged so that the circular plain bearing 222 surrounds the spigot counterpart circular plain bearing 225 and sits inside the counterpart seat base bearing portion 224 to form a concentric bearing assembly. Thus a concentric bearing assembly is provided on each side of the driver's seat.

To facilitate controlled pivoting of the back rest portion 16 relative to the seat sliding portion 14, the hinge mechanism features 250 of the back rest portion 16 are installed.

Hinge Adjustment

In use, the adjustable driver's seat 10 is adjusted as follows. The hinge adjustment handle 260 is pulled upwards so that the handle shaft rotates and the actuating arm 255 depresses the actuating cylinders 254 which in turn operate the actuating valves 253 associated with the pair of pneumatic hydraulic pistons 252. This allows pivoting movement of the back rest portion 16 relative to the seat sliding portion 14 via the concentric bearing assemblies.

Summary

The seat sliding portion 14 is therefore capable of horizontal, back and forth, adjustment relative to the floor engaging structure 12. The floor engaging portion 12 is capable of vertical, up and down, adjustment. The vertical adjustment handle 95 controls the up and down adjustment. The horizontal adjustment handle 146 controls the back and forth adjustment. The hinge adjustment handle 260 controls the hinge adjustment of the back rest portion 16 relative to the seat sliding portion 14.

Feature List 8 - floor 10 - adjustable driver's seat 12 - floor engaging structure 14 - seat sliding portion 16 - back rest portion 20 - floor plate 22 - recessed apertures 24 - circular apertures 30 - square base plate 32 - recessed apertures 40 - cylindrical column 42 - lower end 44 - upper end 50 - vertical plain bearing 52 - channel 54 - counterpart plain bearing 60 - concentric elements 70 - square column 72 - attachment apertures 80 - supports 82 - flange 90 - cover plate 92 - circular apertures 94 - horizontal plain bearing counterpart 95 - vertical adjustment handle 100 - seat frame 102 - upper surface 103 - lower surface 104 - lightening holes 106 - flange 107 - lip 108 - flange 109 - lower surface 104 - horizontal bearing assembly 110 - first hinge arm 111 - lower portion 112 - upper portion 113 - circular bore 114 - smaller circular bore 115 - slot 120 - second hinge arm 130 - hinge mechanism features 140 - horizontal adjustment assembly 141 - inward facing side 142 - horizontal plain bearing 146 - horizontal adjustment handle 147 - forward handle part 148 - rearward handle part 149 - rectangular steel bar 151 - elongate keeper 152 - upper surface 154 - lower surface 158 - bearing surface 162 - upper surface 164 - lower surface 166 - elongate notched member 167 - notches 168 - elongate spacer member 169 - stop 170 - toothed rocker assembly 171 - cut-out termination 172 - rocker 174 - toothed plate 175 - protrusions 200 - seat back 206 - lateral flanges 210 - first hinge arm 211 - lower portion 212 - upper portion 213 - circular bore 214 - smaller circular bore 220 - second hinge arm 222 - circular plain bearing 224 - counterpart seat base bearing portion 225 - spigot counterpart circular bearing 250 - hinge mechanism features 251 - bracket 252 - pneumatic hydraulic piston 253 - actuating valve 254 - actuating cylinder 255 - actuating arm 260 - hinge adjustment handle

Claims

1. An adjustable driver's seat for a railway vehicle, the seat comprising a floor engaging structure; a seat sliding portion; and a back rest portion; the floor engaging structure having a first part and a second part, wherein the back rest portion is pivotably mounted with respect to the seat sliding portion the back rest portion pivotably mounted on at least one concentric bearing assembly; wherein the seat sliding portion is slidably mounted with respect to the floor engaging structure, the seat sliding portion slidably mounted on at least one horizontal plain bearing assembly; and wherein the floor engaging structure is telescopic so as to vary the separation of the seat sliding portion from the first part of the floor engaging structure, the second part of the floor engaging portion being slidably mounted on at least one vertical plain bearing assembly provided on the first part.

2. An adjustable driver's seat for a railway vehicle according to claim 1, wherein the seat sliding portion is slidably mounted on two horizontal plain bearing assemblies.

3. An adjustable driver's seat for a railway vehicle according to claim 1 or claim 2, wherein the first part of the floor engaging surface is mounted on two vertical plain bearing assemblies provided on the second part of the floor engaging surface.

4. An adjustable driver's seat for a railway vehicle according to claim 1, wherein the back rest is pivotably mounted on two concentric bearing assemblies.

5. An adjustable driver's seat for a railway vehicle according to claim 4, wherein the back rest is adjusted by a hydro-pneumatic system.

6. An adjustable driver's seat for a railway vehicle according to any preceding claim, wherein each of the plain bearings assemblies comprise a plain bearing having a channel, the channel defining three bearing surfaces arranged to contact a counterpart plain bearing positioned within the channel.

7. An adjustable driver's seat for a railway vehicle according to claim 6, wherein the or each horizontal plain bearing assemblies includes a stop.

8. An adjustable driver's seat for a railway vehicle according to claim 7, wherein the or each horizontal bearing assembly includes a notched member and a toothed rocker assembly, wherein engagement of the toothed rocker assembly with the notched member prevents sliding movement of the seat sliding portion with respect to the floor engaging portion.

9. An adjustable driver's seat for a railway vehicle according to claim 8, wherein the toothed rocker assembly is biased into engagement with the notched member by a biasing element.

10. An adjustable driver's seat for a railway vehicle according to claim 9, wherein the biasing element is a rod spring.

11. An adjustable driver's seat for a railway vehicle, the adjustable driver's seat substantially as hereinbefore described with reference to figures 1 to 5.