US2118377A - Well pumping device - Google Patents

Description

May 24, 1938. w. J. GOURLEY ET AL WELL PUMPING DEVICE 6 Sheets-Sheet 1 Filed Sept. 14, 1954 May 24, 1938.

w. J. GOURLEY ET AL WELL PUMPING DEVICE Filed Sept. 14, 1934 6 Sheets-Sheet 2 May 24, 1938. w. J. GOURLEY ET AL WELL PUMPING DEVICE Filed Sept. 14, 1954 6 Sheets-Sheet 5 W WM w h M May 24,

1938. w. J. GOURLEY ET AL WELL PUMPING DEVICE Filed Sept. 14, 1934 6 Sheets-Sheet 4 W l l f/lfam J. Qaur/ay Fred H Barney I y 1 w. -J. GIOURLEY ET AL 2,118,377

WELL PUMPING DEVI-CE Filed se t. 14, 1934 6 Sheets-Sheet 5 l W/M m J Gour/ey Q Fred 1% Ear/Icy May 24, 1938.

W. J. GOURLEY ET AL WELL PUMPING DEVICE Filed Sept. 14, 1934 6 Sheets-Sheet 6 Patented May 24, 1938 WELL PUMPING DEVICE William J. Gourley and Fred H. Barney, Fort Worth, Tex.

Application September 14, 1934, Serial No. 744,022

Claims. (01. 74-593) This invention relates to new and useful improvements in well pumping devices.

One object of the invention is to provide a pumping device having improved means for hooking off and on the power transmission elements.

Another object of the invention is to provide an improved guide mechanism co-acting with a hook-off device so as to properly support the working parts either when active or when dormant.

A further object of the invention is to provide a power transmission and hook-off mechanism involving operating devices making for safety, convenience and adjustability, as well as elliciency in operation.

Another object of the invention is to provide means for supporting the coupling elements when the same are disconnected, so that as said elements continue to reciprocate they will not drag on the ground or other support.

Still another object of the invention is to provide an improved pitman-operated power trans mission for pumping a plurality of wells.

A further object of the invention is to provide means for coupling and uncoupling the transmission elements arranged to be operated without the necessity of the operator picking up or grasping the elements.

A construction designed to carry out the invention will be hereinafter described, together with other features of the invention.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings, in which an example of the invention is shown, and wherein:

Figure 1 is a side elevation of a power transmission and hook-off mechanism,

Figure 2 is a plan view of the same,

Figure 3 is an enlarged side view partly in elevation and partly in section,

Figure 4 is a plan view, one of the guides being shown in section,

Figure 4A is a transverse vertical sectional view taken on the line 44 of Figure 3,

Figure 5 is a side view partly in section and partly in elevation showing another form of the invention,

Figure 6 is an enlarged view of the same partly in section and partly in elevation,

Figures 7 and 8 are longitudinally cross sectional views of the same,

Figure 9 is a detail of the hook-off,

Figure 10 is an enlarged transverse vertical sectional view taken on the line l0|0 of Figure 7,

Figure 11 is a plan view of still another form of the invention,

Figure 12 is a longitudinal vertical sectional view of the same,

Figure 13 is a transverse vertical sectional View taken on the line l3-l3 of Figure 11, and

Figure 14 is an elevation of the stirrup.

Figure 15 is a side elevation of an extension guide,

Figure 16 is a plan View of the same.

Figure 17 is a view of another form of the invention, partly in elevation and partly in longitudinal section,

Figure 18 is a vertical sectional view of the hook-off mechanism,

Figure 19 is a longitudinal cross-sectional view, and

Figure 20 is a transverse, vertical sectional view, through the carriage and frame. v

In the drawings the numeral 10 designates an elongated base which may be made of any suitable material, but when placed on the ground is preferably formed of concrete. A flat metal track I l is mounted on top of the base as is shown in Figures 1 and 2 and may have its ends terminating short of the ends of the base. Upright sills I2 extend on each side of the base in parallel relation at the central portion thereof. Guide members l3 are fastened on top of the sills and thus elevated above the track. These guide members are preferably made of metal channels disposed longitudinally of the sills with the open sides opposite. The ends of the channels are braced by bridle bars M.

A carriage I5 is arranged to travel longitudinally between the channels 13. This carriage includes a cross shaft I6 carried by a collar l1 which is connected to the end of a pitman I 8. A yoke l9 carries ears 20 on itsinner ends which are journaled on the shaft l6. vAn oppositely directed yoke 2| has ears 22 at its inner end journaled on the shaft on each side of the collar I? and between said collar and the ears 2!]. Flanged guide rollers 23 are journaled on the ends of the shaft l6 and ride in the channels l3. As is shown in Figure 4'-A the wheels travel on the inner bot-- tom flanges of the channels l3, but are confined against upper displacement by the inner top flanges of said channels.

The pitman 18 may be attached'to the arm of a crank shaft or any other prime mover whereby a reciprocating movement is imparted to said pitman and the carriage I5 is caused to travel back and forth in the channels. By connecting rod lines to the yokes l9 and 2i, it is obvious that two such lines may be operated by the carriage 15,

Each yoke is adapted to be connected with a hook-off bar 24 mounted to slide through a knock-off post 25. These posts are spaced a suitable distance from the ends of the base H) as is shown in Figures 1 to 3 inclusive. Each bar 24 has a plurality of hook-shaped notches 25, one of which is at the inner end of the bar. Each yoke has its outer end reduced and provided with a cross pin 2'! which may be engaged in the end notch 26 or one of the other notches if desired. It will be seen that the reciprocat- 'ing motion of the carriage l5 will be transmitted to the bars 24 by means of the yokes l9 and 2| and said bars thus caused to slide through the 'posts 25.

It is pointed out that should one of the bars 24 be disconnected from its yoke, said yoke being fastened to the shaft It, would immediately fall thus permitting its outer end to drag on the track I. In order to support the outer end, each yoke is provided with a depending roller 28 which will travel on the track II when the yoke is disconnected. Each yoke also has a handle 29 on one side at its outer end so that it may be safely handled by the operator.

Each bar 24 is provided with a head 30 at its outer end whereby it may be clamped to a rod line. When one of the bars 24 is moved inwardly or toward the channels 13, it will exert a pull on the connecting rod coupled thereto which will operate the pump (not shown), whereby the pump rod will be elevated. When the said bar 24 is moved outwardly, the weight of the pump rod will tension the rod line and thus exert a pull on the said bar 24. with a supporting bar 3| fastened on the top of the post and overhanging the bar 24 on the side next to the base 10. A stirrup 32 straddles the bar 24 and has its shank 33 extending upwardly through a hole in the bar 3!. A collar 34 fastened on the shank rests upon the bar and suspends the stirrup. The stirrup has a transverse roller 35 at its lower end.

When it is desired to disconnect one of the bars 24 from its yoke the operator grasps the upper end of the shank 33 and elevates the stirrup until the roller 35 engages the lower edge of the reciprocating bar 24. When one of the notches 26 passes over the roller the latter will be pulled into said notch. This is done on the outward stroke of the bar and consequently, when the roller 35 engages in the notch 25, further outward movement of the bar is arrested but the yoke [9 or 2! will continue its outward movement, whereby the pin 21 will be carried out of its notch 26, thus permitting the outer end of the yoke to drop and disengage from the bar. The yoke will come to rest on its roller 28 while the pull of the rod line will carry the roller 35 into contact with a post 25. From the foregoing it will be seen that the bar 24 may be disconnected with a high factor of safety and without necessitating the workman endangering any member of his body.

So long as a yoke is disconnected it will be reciprocated by the pitman I8, andits outer end 7 will be supported by its roller 28 which will travel on the track l0. When it is desired to couple the yoke and bar, the operator waits until the pin 21 is under the arrested bar 24, at which point he grasps the handle 29 and swings the yoke up- Each post 25 is provided Wardly until its pin 21 engages the bottom edge of said bar. When the yoke moves inwardly toward the channels l3 the pin will be carried into the end notch 26. When this coupling is effected the bar 24 will be moved inwardly and this will automatically release the stirrup 32, whereby the roller 35 will drop out of its notch. Manifestly, the parts may be coupled in a safe and easy manner.

In Figures 5 to inclusive we have shown another form of the invention. This form includes a longitudinal frame 45 made up of sills 4i and top rails 42 connected and secured to uprights or posts 43, 44, 45, 46 and 4? respectively. The tops of the posts 43, 44 and 45 are connected by cross bars 48. The sills 4| may be made of angle bars, each having one leg turned outwardly at the base and the other directed upwardly as is shown in Figure 10. The top rails 42 are preferably formed of angles each having one leg directed downwardly and the other extending inwardly at the top of the angle. 7

Each post 43 to 41 inclusive, is preferably made of a channel bar having its bottom resting on the out-turned leg of the sill and its flat side fastened to the flat outer sides of the sill 4i or rail 42. Guide angles 49 are carried by the posts 43, 44 and 45, below and longitudinally of the top rails. The legs of the angles are disposed so as to co-act with the rails and form guide channels for wheels 55 journaled on the cross shaft 5| of a carriage 52 including a collar 53 secured to a pitman 54. The actuation of the pitman imparts a reciprocating movement to the carriage.

A yoke 55 has ears 56 at its inner end journaled on the carriage, while a second yoke 51 has ears 58 journaled on the carriage outside of the cars 56. The yokes extend in opposite directions from the carriage within the frame, the yoke 51 being larger and longer and underlying the pitman 54. It is desirable to limit the vertical play of the wheels 53 and to accomplish this, those portions of the top rails 42 overlying the guide angles 49 are made vertically adjustable to compensate for wear and irregularities in the frame.

Cross members 59 secured between the posts 43, 44 and 45 have inclined bottoms for receiving wedges 6|] riding on the top rails 42. These wedges are slid by screws 6| threaded through lugs 62 fastened on said rails. The rails (Figure 6) have vertical slots 53 receiving bolts 64 carried by the posts 43, 44 and 45. By loosening the bolts and adjusting the wedges the rails 42 may be adjusted with relation to the wheels 55.

Each yoke has a cross pin 65 (Figure 9) at its outer end provided with inclined spaced bosses 56. These bosses act to displace the hooks 57 on the bottom of a coupling or knock-off bar 58, into engagement with the pin when the yoke is swung upwardly to couple it to said bar. Below the bosses 66, each yoke has a depending roller 69 located to travel on a track 13 (Figures 5, 6 and 9). In order to hold the yoke and bar in engagement a latch pin H is passed through cars 72 on the upper edges of the yoke. By withdrawing the pin the yoke may be swung downwardly when the track is lowered.

For raising and lowering the track it a pair of rock shafts 13 are journaled in the sills 4i) and links 14 fastened on these shafts pivotally support the track. A lever 75 secured to the shaft adjacent each post 41 is used to swing said shaft and thus raise and lower the track. When the track is raised the links and lever are thrown past the perpendicular and the outer end of the I hated in the operation of this device.

track engages a stop 15 carried by the posts 41 (Figures 5 and 6). Suitable latches 15' mounted on the top rail 42 are swung around the levers to hold them in their upright positions. When the lever is swung down to lower one of the tracks it engages in a keeper 11, carried by one of the sills. It will be seen that the outer end of each yoke 55 and 51 is supported on a track at all times.

The end posts 41 not only serve as guides for the bars 68, but also as knock-off posts. The posts at each end of the frame are connected by a cap plate 18 and a cross bar 19 between which the bar 68 at that end slides. The cross bars 19 carry the stops 16 and wear blocks 80 on which the bars 68 slide. The bars 68 are maintained in alinement by upright guides 8| (Figures 6 and 7) fastened between the bars 19 and the plates 18. When the carriage 52 is reciprocated the bars 68 will be slid between the guides 8!.

When it is desired to disconnect one of the bars 68 from its yoke or to engage the pin 65 with another hook 61, to take up slack or relieve tension in the rod line to which the bar is connected, it

is necessary to arrest the bar during its outward stroke. A stirrup 82 similar to that shown in Figure 14 is provided for each coupling bar 68. Each stirrup includes a cross roller 83 journaled between the legs of the stirrup and adapted to engage in the hooks 61 and bear against the vertical edges of the guides 8|. The legs of the stirrup slide vertically through the stop 16 and a keeper 84 carried by the cap plates 18. The top of the stirrup has a single shank 85 serving as a handle.

It is desirable to operate the stirrup in-conjunction with the track 16 and therefore a lever 86 is rested intermediate its ends on the rock shaft 13 adjacent each stirrup so that the lower ends of the stirrup legs rest on the outer end of the lever. The inner end of each lever is loosely mounted on a pin 81 carried by the overhanging track 10. When the lever 15 is swung to lower the track the lever 86 will be swung from the position shown in Figure 6 to the position shown in Figure 9, whereby the stirrup will be elevated. When the track is raised the stirrup will be lowered.

By removing the pin 1| and swinging the lever 15 to the lower track 10, at the end of the frame 4!], during the outward stroke of the coupling bar 68, the track 10 will be lowered and the stirrup 82 will be elevated. When the roller 83 rides into one of the hooks 61, further outward movement of the bar will be stopped, whereby the yoke 55 or 51 will continue to move outwardly which will result in the pin 65 dropping out of its hook 61. This uncoupling operation will be accomplished simply by swinging the lever 15 and without handling either bar 68 or the yoke. Coupling is accomplished by raising the track during the inward stroke of a yoke.

This type of apparatus is particularly advantageous where it is desired to operate opposing rod lines and maintain a straight-line motion.

The yokes 55 and 51 will be reciprocated by the carriage 52 and the rollers 69, traveling on the tracks 19, will support said yokes in the line of travel. The knock-oil bars 68 will be caused to travel in straight lines because of their guides BI and the attachment to the yokes. The hooks 61 provide adjustments, whereby slack in the rod lines may be taken up.

It is obvious that considerable friction is elimi- The wedges 60 take up wear in the guides. thereby limiting the vertical play of the wheels 56. The pins 1| prevent unintentional disconnection of the bars 68 from the yokes.

Safety and convenience are paramount in the operation of the knock-off features. When it is desired to disconnect one of thebars 68, the pin 1| is first withdrawn and then during the outward stroke of said bar, the latter being under the tension of the rod line, the operator merely has to swing the lever 15 from the position shown in Figure 6 to the position shown in Figure 9. This causes the track 18 to be lowered and the stirrup 82 to be elevated, whereby the roller 83 is brought into the path of the hook 61. Just as soon as the roller rides into one of the hooks the outward travel of the bar 68 will be arrested, but the yoke 55 or 51 continuing its outward stroke will carry its pin 65 out of the notch 51, thus permitting the outer end of the yoke to drop until its roller 69 engages the track 10. The bar 68 will be held in its arrested position while the yoke continues to reciprocate, its roller traveling on the track and thereby preventing dragging.

When it is desired to couple one of the bars 68 with its yoke 55 or 51 the operator merely has to swing the lever 15, during the inward stroke of the yoke, from its position in Figure 9 to its position shown in Figure 6. This operation will lower the stirrup 82 and raise the track 1!), whereby the pin 65 will engage in one of the hooks 61 and impart inward movement to the bar 58. This will release the roller 83, whereby the stirrup will drop. The coupling operation is finished by inserting the pin 1! in the ears 12.

Figures 11 to 14 inclusive show another form of the invention, which is particularly adapted to be used in connection with a pumping power rather than a crank and pitrnan. Opposed guide channels 90 are set in a concrete base Bl at a height such as to aline with the pull rod and the rod line. The base is channeled between the guides to receive a carriage 92 formed of top and bottom plates 93 having horizontal guide wheels 94 journaled between their ends and rolling in the guides 90.

A flat pull bar 95 has a collar 96 at its inner end pivoted on a pin 91 fastened in the center of the carriage between the wheels 9@. This permits the bar, which is turned on its edge to swing from side to side, while the carriage is traveling between the guides. A knock-off or coupling bar 98 normally alined with the bar 95 has its inner end rigidly fastened in the carriage between the plates 93, by welding or otherwise. This bar has hooks or notches 99 in the under edge. The guides 90 extend from the base 9| and their outer ends aresupported by posts Mil. This provides a long travel for the carriage.

Near the outer ends of the guides and relatively between the same a knock-off post it! is mounted. This post is slotted to permit the bar 98 to slide therethrough. A stirrup Hi2 straddles the bar 98 and has a roller I03 journaled therein for engag ing in the hooks 99. The legs of the stirrup slide through guide arms i235 secured to each side of the post and also adjacent to upright abutments 505 against which the roller rests when in one of the hooks 99. The shank HEM of the stirrup is slidably confined in a guide bar in? mounted on top of the post lfll. A bell crank lever I58 pivoted in a bracket N15 has its short leg pivoted to the shank to raise and lower the stirrup. A counterbalancing weight 5 it is mounted on the long leg of the lever for supporting the stirrup in itselevated position when the said leg is swung past the perpendicular. The operation of this device will, it is believed, be clear from the descriptions of the other forms.

While any coupler may be employed to connect the outer end of the pull bar 35 with the pull rod, that shown in Figures 11 and 12 is satisfactory. A coupler link III is provided with ears H2 pivoted on a bolt II3 passing through the end of the bar. A stop loop H4 made integral with the ears underlies the bar and engages the lower edge thereof when the link swings downward, thus limiting such swing. A handle II5 has its lower hooked end and secured to the ears, whereby the link may be swung upwardly. A hook I I6 on the end of the pull rod (not shown) is engaged by the link to effect the coupling.

It may be desirable to extend the channels I3 or 95, or the guide members 42 and 49 beyond the knock-off post and to support the outer end of the knock-off bar. between these extended guides to provide either a hold down or a hold up support for the rod lines. In Figures 15 and 16 such an extension is shown. As a matter of convenience, the channels of the forms shown in Figures l1, l2 and 13 have been extended and these extensions are numbered 98, however it is to be understood that this extension may be applied to any of the other forms. The bar 98 is elongated and extends for some distance beyond the post IOI between the channels. The outer end of the bar is carried on an axle I25 which has flanged wheels I2I journaled on its end and supported by the channels 95. A connecting clevis I22 is pivoted on the axle and has the usual rod connection I23 which may be clamped to the rod line. It will be seen that the rod 98 will be maintained in a straight line, but the clevis will permit the rod line to incline either upwardly or downwardly. The outer ends of the channels 95 may be supported on a prop I24. This extension may be advantageously used where the guides are mounted on top of a hill or in a. valley.

The plurality of hook-notches in the sliding bars of each of the structures not only provide for easy and rapid coupling and uncoupling, but further minimize the loss of time and lessen the work in making repairs when the rod lines break.

When. a pull rod line breaks, especially a long line' with a heavy load, the ends of the break will separate from five to ten feet. In making the repair, it usually requires a setof rope blocks or some light weight piece of equipment for pulling the ends together. When the ends are ready to be connected after the break, it is necessary to pull the line back toward the power, as it was necessary to disconnect the pull rod line at or near the power, usually at the knock-off post, so as to obtain slack in the rod line in order to make the connection.

It is obvious that by merely changing the connection of the carriage in the various notches of the sliding bars, it is possible to gain sufiicient slack in the line to repair the same after a break. The notches provide for a longitudinal movement of the rod line with disconnection from the car riage. After the break is repaired, the carriage may be connected in the desired notch and the well pumping operation resumed without delay.

In Figs. 17 to 20 inclusive, I have shown another form of the invention similar to that shown in Figs. 5 and 6. This form has a longitudinal frame, I35, made up of sills I3I and top rails I32, connected and secured touprights I33, I34, I35, and I36 respectively. The tops of the posts I33 and I34 are connected by cross bars I31. The sills I3I may be made of angle bars, each having one leg turned outwardly at the base, and the other directed upwardly, as in Figs. 5 to 10. The top rails I32 are preferably formed of angles, each having one leg directed upwardly and the other extending inwardly at the bottom of the angle.

Each post I33 to I36 inclusive, is preferably made of a channel bar having its bottom resting on the out-turned leg of the sill and its flat side fastened to the flat outer sides of the sill I3I and the rail I32. Guide rails I38 and I39 are carried by the posts I33 and I34 and have their treads directed toward each other, as is shown in Fig. 20.

The guide rails are so arranged as to form guide channels for flanged wheels I40 traveling therebetween, and journaled on a cross shaft I4I of a carriage I42, including a collar I43 secured to a pitman I44. The actuation of the pitman imparts a reciprocating movement to the carriage.

A yoke I45 is pivoted on the cross shaft I4I, while a second yoke I46 is also pivoted on the carriage I42, and these yokes extend in opposite directions on opposite sides of the carriage within the frame. The yoke I45 is larger and longer, and underlies the pitman I44. This yoke I45 is provided with extensions I41 on each side of the yoke I46, and these extensions carry rollers I48. Counter-balances I49 are fastened on the extremities of the extensions and tend to swing the opposite end of the yoke upwardly, whereby said end is elevated. The rollers I48 travel on the lower guide rails I38 and thus support the yoke in this position.

The yoke I45 is provided with extensions I50 within the yoke I45, having counter-balances I5I on their extremities. These counter-balances tend to swing the opposite end of the yoke upwardly and this upward movement is limited by stop fingers I52 carried by the extensions I50, and engaging on the side bars of the yoke I45 to limit the swing of the yoke I43. By this arrangement, the outer ends of the yokes are held in their elevated positions when the device is uncoupled.

As the coupling or knock-off means at each end of the frame is substantially the same, a description of one will explain both. For each yoke a sliding coupling, or knock-01f bar, I53, is provided. This bar has hook notches I54 in its upper edge similar to the bars'in the other forms, the diiference'being that the notches are in the upper edge instead of the lower edge. These notches are adapted to engage the end of the yoke, as is shown in the drawings, and thereby effect a coupling. The posts I35 are connected by a cap plate I55 and a cross bar I55. The bar I53 slides between upright guides I5! fastened between the bar I56 and the cap I55. A wear block of wood or other material I58 is placed between the guides and carried by the bar I55. The coupling bar I53 slides upon this block and-by applying grease to the surface thereof a long wear will be obtained.

So long as the slide bar I53 is under tension, the yoke will remain in engagement with one of the notches I54, but if the outward movement of the bar I53 is arrested, the continued outward movement of the yoke will cause the yoke toride out of the notch, and when this occurs, the end of the yoke will swing upwardly as has been previously described, thus taking it out of the path of the notches. For arresting the slide bar, an inverted stirrup I59 is provided. This stirrup straddles the bar I53 and carries a rounded cross bar I50 adapted'to engage in the notches I54.

The ends of this rounded bar travel in vertical guides I 6! carried by the cap I and the cross bar I56.

When the stirrup is down, the bar I will engage in the notches I54. For elevating this stirrup, a rock shaft I62 is mounted in brackets I63 on the sills I 3I. This shaft is actuated by a lever I64 at one side of the frame. Arms I65 carried by the shaft are pivotally connected with the lower ends of the stirrup. These arms may be counter-balanced if desired. By swinging the lever, I64, it is obvious that the shaft I62 will be rocked and the stirrup raised and lowered. Each yoke may have a handle III] on its outer end for swinging it downwardly to-efiect a coupling. It is believed the operation will be clearly understood from the previous explanations given in connection with the other forms of the invention.

What we claim and desire to secure by Letters Patent is:

1. In a well pumping device, a guide, a reciprocating carriage mounted in said guide and arranged to travel longitudinally thereof, oppositely extending yokes pivoted to said carriage, and knock-on bar having notches for engaging with the outer ends of said yokes.

2. In a well pumping device, a guide, a reciprocating carriage mounted in Said guide and arranged to travel longitudinally thereof, oppositely extending yokes pivoted to said carriage, knock-off bars having notches for engaging with the outer ends of said yokes, knock-01f posts for guiding the bar, and knock-off stirrups co-acting with the posts for engaging the notches in the bars.

3. In a well pumping device, elongated guides, a carriage reciprocating in said guides, oppositely extending yokes having their inner ends pivoted to said carriage, supporting rollers on the outer ends of the yokes, a track below said rollers, and hook-off bars connected with said yokes.

4. In a well pumping device, a guide, a reciprocating carriage mounted in said guide, and arranged to travel longitudinally thereof, a counter-balanced yoke pivoted to and extending longitudinally of said carriage and arranged so that its outer ends Will swing upwardly when released, a sliding coupling bar having notches in its upper edge for engaging with the swinging end of the yoke, a guide for the coupling bar, and a stirrup having means for engaging in one of the notches of the bar and co-acting with the guide to arrest said bar.

5. In a well pumping device, a stationary support, a horizontally opposed parallel pair of elongated guides rigidly mounted on said support and each including upper and lower longitudinal members spaced apart, a carriage reciprocating between the guides and having a supporting roller at each side engaging peripherally in the adjacent guide between the upper and lowermembers thereof, whereby the carriage is retained against lateral movement and is given 'sulficient play to move freely, and also whereby minimum contacts between the carriage wheels and their supports are provided, an upright knock-off post, a bar slidable through the post and having notches in one of its edges, means pivoted to the carriage and engaging a notch in the bar, a knock-off stirrup co-aoting with the post for engaging in a notch of the bar to permit said means to become disengaged therefrom.

TILIZIIAM J. FRED H. BARNEY.

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