CA1088113A - Cushioning device - Google Patents
Cushioning deviceInfo
- Publication number
- CA1088113A CA1088113A CA347,294A CA347294A CA1088113A CA 1088113 A CA1088113 A CA 1088113A CA 347294 A CA347294 A CA 347294A CA 1088113 A CA1088113 A CA 1088113A
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- CA
- Canada
- Prior art keywords
- pad
- ridges
- valleys
- cushion
- ridge
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Abstract
CUSHIONING DEVICE
Abstract of the Disclosure A compression-type cushioning pad provides load-travel characteristics to meet specific shock cushioning requirements. The pad comprises a metal plate having a cushion of elastomer bonded to at least one side thereof, the cushion having corrugated surface configuration con-toured to provide the desired load-deflection characteristics.
Abstract of the Disclosure A compression-type cushioning pad provides load-travel characteristics to meet specific shock cushioning requirements. The pad comprises a metal plate having a cushion of elastomer bonded to at least one side thereof, the cushion having corrugated surface configuration con-toured to provide the desired load-deflection characteristics.
Description
~8~3 This invention relates to rubber cushioned Pads, and more particularly to pads of the type used in railway and mine vehicles or in suspension devices for trucks for cushioning impact and shock.
This is a division of copending Canadian Patent Application Serial No. 288,830, filed on October 17, 1977.
Rubber cushioned pads have been in use for years on railway and mine vehicles for cushioning impacts and shocks. Such pads also have been used in suspension systems on trucks and off-highway vehicles. A typical cushioning pad which has given excellent performance is disclosed in D. Willison United States Patent 2,686,667, in which the rubber cushion thereof has a corrugated surface. In that patent the ridges in the corrugations are linear and of constant cross-sectional area throughout their length.
When a pad o such configuration is compressed, the opposing side faces of the ridges will bulge toward each other and will come into contact first at the midpoint o~
the ridges and such contact will progressively increase toward the ends of the ridges until the faces are engaged substantially the entire length of the ridges. Once the faces of the ridges are in contact, the valleys are, of course, completely filled and under ~urther loading the cushion will compress as though it were a block of solid body. The load-deflection characteristics of that pad will be such as to produce a stiffer action at light loads than may be desirable for a given type of service.
The present invention is directed to a pad having a resilient cushion oE corrugated configuration having alternate ridges and valleys. In the preferred embodiment the sides o~ the rid~es are so contoured that as the cushion is compressed, they will flow inwardly toward each other in ~ L
cbr/ ~~
~ . . . . .
~8~3 such a manner as to come into contact approximately simultaneously over their entire length. In this manner, full-length contact between the opposing sides o~ the ridges is delayed as compared with the pad in the afore-mentioned patent. Hence, at light loads this pad will provide a larger deflection and, therefore, softer action than the prior art pad. In another form of pad the sides of the ridges may be so contoured as to cause the opposing sides of the ridges to engage at their midpoint shortly after the pad is subjected to a compressive loading. This form of pad results in a stiffer action than the pad having its ridges of constant cross-sectional area and also provides greater deElection at higher load levels.
An object is to provide a cushioning pad of the afoxementioned type whereby a modiied force-travel ~
characteristic is obtained, particularly in the early stages of compression of the pad. ``
A further object is to provide a cushioning pad having an elastomeric cushion bonded to a metallic plate, the cushion having a corrugated surface configuration wherein the ridges of the corrugations are so contoured as to provide a load rate for suspension devices for trucks and other ~ehicles that is particularl~ suitable or empty or light load conditions.
A more specific object is to provide a cushioning pad having an elastomeric cushion formed with a corrugated surface configuration, the cross-sectional area of the ridges oE the cushion var~ing at a predetermined rate from mid- ;
point o~ a ridge to its ends~
Accordin~ to the present invention there is pro~ided a compression type cushioning pad, the pad including a rigid planar plate having a palr of parallel
This is a division of copending Canadian Patent Application Serial No. 288,830, filed on October 17, 1977.
Rubber cushioned pads have been in use for years on railway and mine vehicles for cushioning impacts and shocks. Such pads also have been used in suspension systems on trucks and off-highway vehicles. A typical cushioning pad which has given excellent performance is disclosed in D. Willison United States Patent 2,686,667, in which the rubber cushion thereof has a corrugated surface. In that patent the ridges in the corrugations are linear and of constant cross-sectional area throughout their length.
When a pad o such configuration is compressed, the opposing side faces of the ridges will bulge toward each other and will come into contact first at the midpoint o~
the ridges and such contact will progressively increase toward the ends of the ridges until the faces are engaged substantially the entire length of the ridges. Once the faces of the ridges are in contact, the valleys are, of course, completely filled and under ~urther loading the cushion will compress as though it were a block of solid body. The load-deflection characteristics of that pad will be such as to produce a stiffer action at light loads than may be desirable for a given type of service.
The present invention is directed to a pad having a resilient cushion oE corrugated configuration having alternate ridges and valleys. In the preferred embodiment the sides o~ the rid~es are so contoured that as the cushion is compressed, they will flow inwardly toward each other in ~ L
cbr/ ~~
~ . . . . .
~8~3 such a manner as to come into contact approximately simultaneously over their entire length. In this manner, full-length contact between the opposing sides o~ the ridges is delayed as compared with the pad in the afore-mentioned patent. Hence, at light loads this pad will provide a larger deflection and, therefore, softer action than the prior art pad. In another form of pad the sides of the ridges may be so contoured as to cause the opposing sides of the ridges to engage at their midpoint shortly after the pad is subjected to a compressive loading. This form of pad results in a stiffer action than the pad having its ridges of constant cross-sectional area and also provides greater deElection at higher load levels.
An object is to provide a cushioning pad of the afoxementioned type whereby a modiied force-travel ~
characteristic is obtained, particularly in the early stages of compression of the pad. ``
A further object is to provide a cushioning pad having an elastomeric cushion bonded to a metallic plate, the cushion having a corrugated surface configuration wherein the ridges of the corrugations are so contoured as to provide a load rate for suspension devices for trucks and other ~ehicles that is particularl~ suitable or empty or light load conditions.
A more specific object is to provide a cushioning pad having an elastomeric cushion formed with a corrugated surface configuration, the cross-sectional area of the ridges oE the cushion var~ing at a predetermined rate from mid- ;
point o~ a ridge to its ends~
Accordin~ to the present invention there is pro~ided a compression type cushioning pad, the pad including a rigid planar plate having a palr of parallel
2 -cbr/~il ~` .......
surfaces and a single elastomeric cushion bonded to and covering each of the surfaces, the cushions extending from the plate in opposite directions. Each of the cushions has alternate ridges and valleys formed therein and extending across the pad, the valleys in a direction crosswise thereof being generally concavely shaped relative to the plane o~ the plate and extending to at least adjacent the top of the ridges. Each ridge between adjacent valleys has a flat top and a maximum cross-sectional area at its longitudinal midpoint and a pair oopposing longitudinally extending sides which are generally convexly shaped in a lengthwise direction relative to the `
longitudinal axis of the ridge. The flat tops of the ridges o each cushion is in substantiall~ the same plane parallel to the plane o the plat~. The ridges and valleys are so contoured that upon compression of the cushions of the pad the opposing sides of adjacent ridges will flow towards each other in such a manner as to cause the valleys therebetween to fill commencing at the bottom thereof and progressing in the direction away rom the plate member.
The eatures and advantages of the invention will become apparen~ rom the detailed description taken in conjunction with the accompanying drawings.
Brief Description of the Drawings Fig. 1 is a plan view of a cushioning pad.
Fig. la is a vertical section taken along line la-la o Flg. 1.
Fig. lb is a vertical section taken along line lb-lb of Fig. 1.
Fig. 2 is a s;de elevational view of the pad shown in Fig. 1.
Fig. 3 is an end view of the pad o~ Fig. 1.
~, cbr/~u~:~
~ 8~1~3 Fig. 4 is a side elevational view of pads of the type shown in Fig. 1 compressed a predetermined amount.
Fig. 4a is a side elevational view of the pads of Fig. 4 compressed an additional amount.
Fig. 5 is a plan view of the pad shown in Fig. 1 but illustrating the flow of the ridges into the valleys during the compression of the pad.
Fig. 6 is a graph showing typical load-travel curves for various cushioning pads.
Fig. 7 is a plan view of a cushioning pad of the prior art type. `
Fig. 7a is a side elevational view of the pad shown in Fig. 7.
Fi~. 8 is a plan view of a cushioning pad according to the present invention.
E'ig. 9 is a plan view of a group of pads embodying the invention applied to a railway vehicle.
Description of the Preferred Embodiments :
Cushioning pad 10 comprises a flat metallic plate 12 having a resilient cushion 1~ of an elastomer such as rubber or similar material bonded to each side thereof. Cushion 14 in its free or uncompressed condition has a corrugated surface configuration comprising alternate ridges 16 and valleys 18 extending across the pad. In Fig. 1 three ridges and two valleys are shown for purposes of illustration, it being understood, however, that a greater number of ridges and valleys may be provided depending on the pad size and capacity required. It will `
be apparent that two ridses with a valley therebetween are the minimum number that is practicable. Cushion 14 at its peripheral edges slopes gradually upwardly from the surface of the plate, as at 20, to the edge of flat tops . ' .- ~
cbr/~'~
16a of rid~es 16. The thickness of the elastomer at each ridge 16 is preferably of the same dimension, each flat top surface 16a lying in a plane parallel to the plane o~ plate 12. The thickness of the elastomer at bottom of valley 18 may vary depending on the load-deflection characteristics required but, for manufacturing purposes and pad durability, should not be less than a~out 10~ of the thickness of the ridges. In order to accurately align a group of pads in face-to-face engagement the pad is provided with a dowel 21 and a complementary recess 22.
Dowel 21 is preferably in the shape of the frustum of a cone. The fit between the dowel and a dowel recess in an adjacent pad is precise so that accurate alignment of a group of pads is obtained. --The opposing sides oE ridges 16 are concavely contoured in a lengthwise direction as at 16b (see Fig. 1).
This configuration results in the cross-sectional area of each ridge being a minimum midway between its ends and a maximum at each end, as seen in Figs. la and lb. It will be noted in Figs. la and lb that valleys 18 in transverse section are also concavely shaped, and ~or purposes o~
illustration are o~ approximately the same area as ridges 16~ The outer sides o~ end ridges 16 are shown as being linear.
As the pad is subjected to a compressive load, the opposing sides 16b Qf the ridges will bulge or flow toward each other, thereby decreasing the size of valley 18. As the compression of the pad continues, sides 16b attain the position shown in Fig. 4 in which the valleys 18 have become filled to a considerable extent. In Fig.
5, dot-dash line "x" represents the leading edge of the side surface 16b when the pad is compressed about the same :
cbr/~ .J
~, 8~L~3 amount as in Fig. 4. It will be observed that line x is less concave than the edge "e" of the ridge in its unloaded condition. As the pad is compressed further, the opposing sides of the ridges move closer together and come into contact substantially simultaneously along a straight line.
This filling of the valley is illustrated in Fig. 4a and also in Fig. 5 in which line "f" represents the common line of engagement between the sides of the ridges. Once the valleys have been filled the cushion becomes in effect ~````
a solid block and upon further compressive loading the elastomer expands only along its outer peripheral surfaces.
Prior to explaining the load-travel characteristics ;
of the pad, reference is made to the prior art pad 29 shown in Figs. 7 and 7a, in which the ridges 30 are straight and oE constant cross-sectional area. As this pad is compressed,-contact between the opposing sides 32 of the ridges will occur first at the midpoint of the ridges.
As compression of the pad continue~, the engagement between the sides of ~he ridges will progre!ss from the initial contact at midpoint toward the ends of the ridges until tha valleys are ~illed and complete engagement exists.
Re~erring now to Fig. 6, in which loaa in thousands of pounds is plotted against the travel or com-pression in inches, curve A represents the approxi~ate load-travel characteristics of a block-type pad, such as one in which the cushion corresponds approximately in size and shape to that shown in Figs. 1 or 7 but without the corr~lga~ions. This curve indicates that even for small initial deflection or travel the load increases rapidly.
In other words, this pad will provide sti~f cushioning action under light loads. It will also offer maximum resistance to compression at increasing loads, as seen from cbr~
the steepness o~ the curve at the higher load levels.
Curve B represents the load-travel characteristics of the prior art pad of Fig. 7. Curve B indicates that the Fig. 7 pad has a softer overall cushioning action than the bloc~ pad. On curve B point "p" indicates the load and travel at which the opposing sides 32 of pad 29 initially engage midway between the ends of the ridges, and point "r" the load and travel at which sides 32 are fully engaged. It will be noted that the slope of the curve increases rapidly between points p and r, signifyin~ an accelerating load rate or resistance of the pad to com-pression.
Curve C represents the load-travel characteristics for the improved pad of Figs 1, 2 ~nd 3. An irlspection oE thiq curve reveals that it has a lesser slope than curve B from zero to about .45 inches displacement. This indicates a softer action for light to moderate loads than the prior art pad and shows that fclr a given load applied to the pad a greater deflection or compression thereof will occur. At point "s" on curve C, the sides of the ridges are not yet engaged but at "t" the engagement o~ the ridges and consequent filling of the valleys has been completed.
~t point t the pad acts virtually as a solid block and the curve from that point on progresses steeply upwards.
The load-travel characteristics as shown by curve C are particularly desirable for use in a suspension mechanism for vehicles such as trucks and off-highway equipment in which sot action is desirable for empty or light loads. Thus, the pad provides the advantage of soft light load cushioning along with reserve capacity for handling heavy loads. It will be understood that while the configuration of curve C
is typical for the improved pad, the load-travel character-cbr~
-~' .
.
.
~ OE~8~L3istics of a prescribed size of pad to meet specified service requirements are dependent on various factors such as, for example, the thickness and hardness o~ the elastomer cushion, and the number and spacing of the ridges. One or more of these factors may be varied to obtain the desired pad performance. A pad having its resilient cushion contoured in accordance with the invention so that the sides of the ridges will engage approximately simultaneously at a predetermined load will provide softer cushioning action at light loads than the prior art pad of Fig. 7 of comparable size.
The above-described pad wherein the ridges have a minimum cross-sectional area at its longitudinal midpoint is also described and is claimed in above-identiied parent application Serial No. 288,830. ~
In Fig. 8 , according to the present invention, -there i~ shown a pad in which the elastomeric cushion 40 has a ridge and valley configuration that is in a sense the reverse o the previous embodiments. The opposing sides of ridges 42 diverge outward:Ly from the midpoint of the ridges to the ends thereof. The load-travel characteristics Qf this pad are represented by curve D in Fig. 6. It will be seen that the most of curve D falls between that of curves A and B. ~hus, the modified pad provides softer action than a cushion of the solid block type but is stiffer than the prior art cushion for light and intèrmediate loads. This results from the engagement at the midpoint o~ the opposing sides of the ridges, which occurs earlier than the prior art pad or the pad of Fig. 1, during compression of the pad. As the load on this pad is increased, the engac3ement between the opposing sides of the ridges progressively increases toward the ends of the ' .
cbr/i~3 `
ridges but at a slower rate than for the pads having Fig.
1, Fig. 7 or Fig. 8 configurations. Curve D, therefore, in its upper portions crosses curves B and C, which results from the fact that higher loading is required to close the valleys near the end of the ridges. This pad, therefore, offers load-travel characteristics that are suitable for use in cushioning arrangements requiring softer action than the solid block-type cushioning pad provides.
Fig. 9 illustrates the application of a group of pads 10 em~odying the invention to a railway vehicle.
The pads are disposed in the usual draft gear pocket formed by the car frame 50. Front and rear followers 52 and 54, respectively, are in engagement with stops 56 and 58 on the car frame. A yoke 60 surrounds the pads and followers ancl transmits draft and buffing loads to the pads. A car coupler (not shown) is connected to the forward end 62 of the yoke. It will be observed that end pads ~
of the group have a resilient cushion 14 only on one side of plate 12. This avoids ab~asion of the cushion by the followers, as would occur if the end pad were to have cushion 14 on both sides of the plate.
A group of pads such as shown in Fig. 9 may, of course, be vertically arranged ~or use in suspension systems for trucks and off-highway vehicles.
cbr/ ~~
surfaces and a single elastomeric cushion bonded to and covering each of the surfaces, the cushions extending from the plate in opposite directions. Each of the cushions has alternate ridges and valleys formed therein and extending across the pad, the valleys in a direction crosswise thereof being generally concavely shaped relative to the plane o~ the plate and extending to at least adjacent the top of the ridges. Each ridge between adjacent valleys has a flat top and a maximum cross-sectional area at its longitudinal midpoint and a pair oopposing longitudinally extending sides which are generally convexly shaped in a lengthwise direction relative to the `
longitudinal axis of the ridge. The flat tops of the ridges o each cushion is in substantiall~ the same plane parallel to the plane o the plat~. The ridges and valleys are so contoured that upon compression of the cushions of the pad the opposing sides of adjacent ridges will flow towards each other in such a manner as to cause the valleys therebetween to fill commencing at the bottom thereof and progressing in the direction away rom the plate member.
The eatures and advantages of the invention will become apparen~ rom the detailed description taken in conjunction with the accompanying drawings.
Brief Description of the Drawings Fig. 1 is a plan view of a cushioning pad.
Fig. la is a vertical section taken along line la-la o Flg. 1.
Fig. lb is a vertical section taken along line lb-lb of Fig. 1.
Fig. 2 is a s;de elevational view of the pad shown in Fig. 1.
Fig. 3 is an end view of the pad o~ Fig. 1.
~, cbr/~u~:~
~ 8~1~3 Fig. 4 is a side elevational view of pads of the type shown in Fig. 1 compressed a predetermined amount.
Fig. 4a is a side elevational view of the pads of Fig. 4 compressed an additional amount.
Fig. 5 is a plan view of the pad shown in Fig. 1 but illustrating the flow of the ridges into the valleys during the compression of the pad.
Fig. 6 is a graph showing typical load-travel curves for various cushioning pads.
Fig. 7 is a plan view of a cushioning pad of the prior art type. `
Fig. 7a is a side elevational view of the pad shown in Fig. 7.
Fi~. 8 is a plan view of a cushioning pad according to the present invention.
E'ig. 9 is a plan view of a group of pads embodying the invention applied to a railway vehicle.
Description of the Preferred Embodiments :
Cushioning pad 10 comprises a flat metallic plate 12 having a resilient cushion 1~ of an elastomer such as rubber or similar material bonded to each side thereof. Cushion 14 in its free or uncompressed condition has a corrugated surface configuration comprising alternate ridges 16 and valleys 18 extending across the pad. In Fig. 1 three ridges and two valleys are shown for purposes of illustration, it being understood, however, that a greater number of ridges and valleys may be provided depending on the pad size and capacity required. It will `
be apparent that two ridses with a valley therebetween are the minimum number that is practicable. Cushion 14 at its peripheral edges slopes gradually upwardly from the surface of the plate, as at 20, to the edge of flat tops . ' .- ~
cbr/~'~
16a of rid~es 16. The thickness of the elastomer at each ridge 16 is preferably of the same dimension, each flat top surface 16a lying in a plane parallel to the plane o~ plate 12. The thickness of the elastomer at bottom of valley 18 may vary depending on the load-deflection characteristics required but, for manufacturing purposes and pad durability, should not be less than a~out 10~ of the thickness of the ridges. In order to accurately align a group of pads in face-to-face engagement the pad is provided with a dowel 21 and a complementary recess 22.
Dowel 21 is preferably in the shape of the frustum of a cone. The fit between the dowel and a dowel recess in an adjacent pad is precise so that accurate alignment of a group of pads is obtained. --The opposing sides oE ridges 16 are concavely contoured in a lengthwise direction as at 16b (see Fig. 1).
This configuration results in the cross-sectional area of each ridge being a minimum midway between its ends and a maximum at each end, as seen in Figs. la and lb. It will be noted in Figs. la and lb that valleys 18 in transverse section are also concavely shaped, and ~or purposes o~
illustration are o~ approximately the same area as ridges 16~ The outer sides o~ end ridges 16 are shown as being linear.
As the pad is subjected to a compressive load, the opposing sides 16b Qf the ridges will bulge or flow toward each other, thereby decreasing the size of valley 18. As the compression of the pad continues, sides 16b attain the position shown in Fig. 4 in which the valleys 18 have become filled to a considerable extent. In Fig.
5, dot-dash line "x" represents the leading edge of the side surface 16b when the pad is compressed about the same :
cbr/~ .J
~, 8~L~3 amount as in Fig. 4. It will be observed that line x is less concave than the edge "e" of the ridge in its unloaded condition. As the pad is compressed further, the opposing sides of the ridges move closer together and come into contact substantially simultaneously along a straight line.
This filling of the valley is illustrated in Fig. 4a and also in Fig. 5 in which line "f" represents the common line of engagement between the sides of the ridges. Once the valleys have been filled the cushion becomes in effect ~````
a solid block and upon further compressive loading the elastomer expands only along its outer peripheral surfaces.
Prior to explaining the load-travel characteristics ;
of the pad, reference is made to the prior art pad 29 shown in Figs. 7 and 7a, in which the ridges 30 are straight and oE constant cross-sectional area. As this pad is compressed,-contact between the opposing sides 32 of the ridges will occur first at the midpoint of the ridges.
As compression of the pad continue~, the engagement between the sides of ~he ridges will progre!ss from the initial contact at midpoint toward the ends of the ridges until tha valleys are ~illed and complete engagement exists.
Re~erring now to Fig. 6, in which loaa in thousands of pounds is plotted against the travel or com-pression in inches, curve A represents the approxi~ate load-travel characteristics of a block-type pad, such as one in which the cushion corresponds approximately in size and shape to that shown in Figs. 1 or 7 but without the corr~lga~ions. This curve indicates that even for small initial deflection or travel the load increases rapidly.
In other words, this pad will provide sti~f cushioning action under light loads. It will also offer maximum resistance to compression at increasing loads, as seen from cbr~
the steepness o~ the curve at the higher load levels.
Curve B represents the load-travel characteristics of the prior art pad of Fig. 7. Curve B indicates that the Fig. 7 pad has a softer overall cushioning action than the bloc~ pad. On curve B point "p" indicates the load and travel at which the opposing sides 32 of pad 29 initially engage midway between the ends of the ridges, and point "r" the load and travel at which sides 32 are fully engaged. It will be noted that the slope of the curve increases rapidly between points p and r, signifyin~ an accelerating load rate or resistance of the pad to com-pression.
Curve C represents the load-travel characteristics for the improved pad of Figs 1, 2 ~nd 3. An irlspection oE thiq curve reveals that it has a lesser slope than curve B from zero to about .45 inches displacement. This indicates a softer action for light to moderate loads than the prior art pad and shows that fclr a given load applied to the pad a greater deflection or compression thereof will occur. At point "s" on curve C, the sides of the ridges are not yet engaged but at "t" the engagement o~ the ridges and consequent filling of the valleys has been completed.
~t point t the pad acts virtually as a solid block and the curve from that point on progresses steeply upwards.
The load-travel characteristics as shown by curve C are particularly desirable for use in a suspension mechanism for vehicles such as trucks and off-highway equipment in which sot action is desirable for empty or light loads. Thus, the pad provides the advantage of soft light load cushioning along with reserve capacity for handling heavy loads. It will be understood that while the configuration of curve C
is typical for the improved pad, the load-travel character-cbr~
-~' .
.
.
~ OE~8~L3istics of a prescribed size of pad to meet specified service requirements are dependent on various factors such as, for example, the thickness and hardness o~ the elastomer cushion, and the number and spacing of the ridges. One or more of these factors may be varied to obtain the desired pad performance. A pad having its resilient cushion contoured in accordance with the invention so that the sides of the ridges will engage approximately simultaneously at a predetermined load will provide softer cushioning action at light loads than the prior art pad of Fig. 7 of comparable size.
The above-described pad wherein the ridges have a minimum cross-sectional area at its longitudinal midpoint is also described and is claimed in above-identiied parent application Serial No. 288,830. ~
In Fig. 8 , according to the present invention, -there i~ shown a pad in which the elastomeric cushion 40 has a ridge and valley configuration that is in a sense the reverse o the previous embodiments. The opposing sides of ridges 42 diverge outward:Ly from the midpoint of the ridges to the ends thereof. The load-travel characteristics Qf this pad are represented by curve D in Fig. 6. It will be seen that the most of curve D falls between that of curves A and B. ~hus, the modified pad provides softer action than a cushion of the solid block type but is stiffer than the prior art cushion for light and intèrmediate loads. This results from the engagement at the midpoint o~ the opposing sides of the ridges, which occurs earlier than the prior art pad or the pad of Fig. 1, during compression of the pad. As the load on this pad is increased, the engac3ement between the opposing sides of the ridges progressively increases toward the ends of the ' .
cbr/i~3 `
ridges but at a slower rate than for the pads having Fig.
1, Fig. 7 or Fig. 8 configurations. Curve D, therefore, in its upper portions crosses curves B and C, which results from the fact that higher loading is required to close the valleys near the end of the ridges. This pad, therefore, offers load-travel characteristics that are suitable for use in cushioning arrangements requiring softer action than the solid block-type cushioning pad provides.
Fig. 9 illustrates the application of a group of pads 10 em~odying the invention to a railway vehicle.
The pads are disposed in the usual draft gear pocket formed by the car frame 50. Front and rear followers 52 and 54, respectively, are in engagement with stops 56 and 58 on the car frame. A yoke 60 surrounds the pads and followers ancl transmits draft and buffing loads to the pads. A car coupler (not shown) is connected to the forward end 62 of the yoke. It will be observed that end pads ~
of the group have a resilient cushion 14 only on one side of plate 12. This avoids ab~asion of the cushion by the followers, as would occur if the end pad were to have cushion 14 on both sides of the plate.
A group of pads such as shown in Fig. 9 may, of course, be vertically arranged ~or use in suspension systems for trucks and off-highway vehicles.
cbr/ ~~
Claims (2)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A compression-type cushioning pad, comprising:
(a) a rigid planar plate having a pair of parallel surfaces; and (b) a single elastomeric cushion bonded to and covering each of the surfaces, the cushions extending from the plate in opposite directions, each of the cushions having alternate ridges and valleys formed therein and extending across the pad, the valleys in a direction cross-wise thereof being generally concavely shaped relative to the plane of the plate and extending to at least adjacent the top of the ridges, each ridge between adjacent valleys having a flat top and a maximum cross-sectional area at its longitudinal midpoint and a pair of opposing longi-tudinally extending sides which are generally convexly shaped in a lengthwise direction relative to the longi-tudinal axis of the ridge, the flat tops of the ridges of each cushion being in substantially the same plane parallel to the plane of the plate, the ridges and valleys being so contoured that upon compression of the cushions of the pad the opposing sides of adjacent ridges will flow toward each other in such a manner as to cause the valleys there-between to fill commencing at the bottom thereof and progressing in a direction away from the plate member.
(a) a rigid planar plate having a pair of parallel surfaces; and (b) a single elastomeric cushion bonded to and covering each of the surfaces, the cushions extending from the plate in opposite directions, each of the cushions having alternate ridges and valleys formed therein and extending across the pad, the valleys in a direction cross-wise thereof being generally concavely shaped relative to the plane of the plate and extending to at least adjacent the top of the ridges, each ridge between adjacent valleys having a flat top and a maximum cross-sectional area at its longitudinal midpoint and a pair of opposing longi-tudinally extending sides which are generally convexly shaped in a lengthwise direction relative to the longi-tudinal axis of the ridge, the flat tops of the ridges of each cushion being in substantially the same plane parallel to the plane of the plate, the ridges and valleys being so contoured that upon compression of the cushions of the pad the opposing sides of adjacent ridges will flow toward each other in such a manner as to cause the valleys there-between to fill commencing at the bottom thereof and progressing in a direction away from the plate member.
2. The cushioning pad as set forth in claim l in which each of the opposing longitudinal sides of at least each ridge between adjacent valleys consists of two straight sides which intersect at a point midway between opposing ends of said ridge.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA347,294A CA1088113A (en) | 1976-11-12 | 1980-03-07 | Cushioning device |
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/741,388 US4111406A (en) | 1976-11-12 | 1976-11-12 | Cushioning device |
| US741,388 | 1976-11-12 | ||
| CA288,830A CA1086335A (en) | 1976-11-12 | 1977-10-17 | Cushioning device |
| CA347,294A CA1088113A (en) | 1976-11-12 | 1980-03-07 | Cushioning device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1088113A true CA1088113A (en) | 1980-10-21 |
Family
ID=27165323
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA347,294A Expired CA1088113A (en) | 1976-11-12 | 1980-03-07 | Cushioning device |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1088113A (en) |
-
1980
- 1980-03-07 CA CA347,294A patent/CA1088113A/en not_active Expired
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |