US2801485A

US2801485A - Spring finger for magazines

Info

Publication number: US2801485A
Application number: US505885A
Authority: US
Inventors: Marsh Roger
Original assignee: WEAPONS Inc
Current assignee: WEAPONS Inc
Priority date: 1955-05-04
Filing date: 1955-05-04
Publication date: 1957-08-06
Anticipated expiration: 1974-08-06

Description

1957 R. MARSH SPRING FINGER FOR MAGAZINES 2 Sheets-Sheet 1 Filed lay 4, 1955 INVENTOR F1 Roger- Marsh %a ,a;awm

ATTORNEYS Aug. 6, 1957 MARSH 2,801,485

SPRING FINGER FOR MAGAZINES Filed llay 4, 1955 2 Sheets-Sheet 2 United States Patent SPRING FINGER FOR MAGAZINES Roger Marsh, Hudson, Ohio, assignor to Weapons, Inc., Hudson, Ohio, a corporation of Ohio Application May 4, 1955, Serial No. 505,885

3 Claims. (CI. 42-50) The present invention relates to means for preventing improper loading of magazines and more particularly to a spring finger or the like engageable with the base of an improperly loaded cartridge in a magazine to indicate such improper loading.

Heretofore serious malfunctions have occurred in firearms due to improper loading of cartridges in the magazine. Such malfunctions are apt to occur if the base or rim of a cartridge is not ahead of the rim of the cartridge immediately below it since the rim of the upper cartridge may catch on the rim of the lower cartridge during advancing of the upper cartridge toward the barrel.

According to the present invention a suitable projection, tumbler, spring finger or the like is provided in the rear wall of the magazine which does not interfere with normal loading of the magazine but engages or catches the rim of an improperly loaded round to indicate to the person loading the magazine that something is wrong and/or to prevent further loading until the otfending round is loaded properly. A stationary projection may provide satisfactory results, but it is preferable to employ a yieldable spring-pressed finger for this purpose. Such a yieldable finger may be employed on drum magazines, staggered-double-row box magazines, single-row magazines, and various other magazines.

An object of the invention is to provide a simple and inexpensive means to prevent improper loading of magazines.

Other objects, uses and advantages of the invention will become apparent to those skilled in the art from the following description and claims and from the drawings in which:

Figure 1 is a fragmentary longitudinal vertical sectional view on a large scale showing a single-row box magazine containing the spring finger of the present invention;

Figure 2 is a fragmentary end elevational view taken substantially on the line indicated at 2-2 of Fig. 1;

Figure 3 is a fragmentary longitudinal vertical sectional view of the magazine of Fig. 1 showing the position of the parts when the magazine contains a series of properly loaded cartridges;

Figure 4 is a vertical sectional view similar to Fig. 3 showing the position of the parts when one of the cartridges is loaded improperly with its rim behind the rim of a lower cartridge;

Figure 5 is a fragmentary longitudinal vertical sectional view of a modified box magazine similar to the magazine of Figs. 1 and 2 and on the same scale showing the position of the parts when the magazine contains a series of properly loaded cartridges;

Figure 6 is a fragmentary side elevational view on a large scale with parts broken away and shown in section showing another modified form of magazine according to the present invention;

Figure 7 is a fragmentary end elevational view of the magazine of Fig. 6;

Figure 8 is a fragmentary longitudinal vertical sec- 2,801,485 Patented Aug. 6, 1957 tional view on a large scale of a double-staggered-row box magazine according to the present invention, the parts being shown in their positions when the cartridges are properly loaded;

Figure 9 is a fragmentary end elevational view of the magazine of Fig. 8; and

Figure 10 is a fragmentary end elevational view with parts broken away and parts omitted showing the operation of the spring finger of the magazine of Figs. 8 and 9 when a cartridge is loaded improperly.

Referring more particularly to the drawings in which like parts are identified with the same numerals throughout the several views, Figs. 1 to 4 show a single-row box magazine A having parallel side walls 1 and 2 and sub stantially

parallel end walls

3 and 4 defining a sheet metal receptacle of substantially rectangular horizontal cross section for receiving a series of cartridges 5. The side walls I and 2 are provided at their upper ends with inturned stop flanges or lips 6 and 7 which serve as stop members to limit upward movement of the cartridges 5 and to hold the uppermost cartridge as shown in Figs. 1 to 3 in a discharge position for feeding to the chamber of the barrel. The front upper portion of the magazine is cut away in a conventional manner so that the top edge of the end wall 4 is just below the nose of the uppermost cartridge and said cartridge may be moved forwardly under the magazine lips 6 and 7 and out of the magazine. The box magazine A may be made of a standard size so as to fit conventional firearms and may be held in place on the firearm in a conventional manner.

A sheet-metal magazine platform or follower 8 of sub stantially uniform width and length and of a size to fit in the cartridgereceiving receptacle formed by the sheet metal walls 1 to 4 is mounted in said receptacle for vertical sliding movement and is biased upwardly by a resilient sheet-metal spring 9 of uniform width that engages the platform 8 and the bottom of the magazine A. As in conventional magazines, the magazine platform 8 engages the lowermost cartridge, supports the cartridges in the magazine, and holds the uppermost cartridge against the upper lips 6 and 7.

The magazine is loaded in a conventional manner by depressing the magazine platform and moving individual cartridges 5 horizontally over the upper edge of the end wall 4 and under the lips 6 and 7 toward the end Wall 3. Each cartridge 5 is of a conventional type and has a cartridge case with a circular rim 10 that projects radially beyond the generally cylindrical outer surface of the cartridge case body substantially as shown in Figs. 1 to 5. When the cartridges are properly loaded in the magazine as shown in Fig. 3, the rim 10 of each cartridge above the lowermost cartridge is just ahead of the rim 10 of the cartridge immediately below it and no difficulty is involved in moving each cartridge forwardly out of the magazine after it reaches the top of the magazine. However, when the rim 10 of one of the cartridges is behind the rim 10 of the next lower cartridge, the rim of the latter cartridge tends to resist forward movement of the rim of the former cartridge as shown in Fig. 4 and malfunctions of the firearm on which the magazine is mounted are apt to occur.

Such malfunctions may be avoided by proper loading of the magazine and by insuring that the rim of each cartridge in the magazine is forwardly of the rim of the cartridge immediately below it. The present invention provides a simple means to indicate incorrect loading of the magazine so that such improper loading may be avoided. One of the simplest ways to prevent improper loading is to provide a spring finger or the like in the rear wall of the magazine for engaging the bases of cartridges placed in the magazine. As shown in Figs. 1 to 4, the rear wall 3 is provided with a rectangular opening 11 halfway between the side walls 1 and 2 and a resilient sheet-metal spring finger 12 of substantially uniform width and length that projects through said opening for engaging the bases of the cartridges 5 as they are lowered in the magazine. The lower portion of the spring finger may be welded to or otherwise rigidly secured to the wall 3 and, if desired, may be reversely bent to provide a lug or projection 13 for engaging a magazine catch on the firearm.

As shown herein, the cantilever spring finger 12 has a straight fiat horizontal upper surface 14 below the upper marginal edge of the opening 11 and below the base of the uppermost cartridge in the magazine A for catching the rim of an improperly loaded round before it is lowered to permit loading of an additional round. If a cartridge 5 is loaded improperly as shown in Fig. 4 so that its rim 10 is behind the rim of the lower cartridge, the spring finger 12 will swing forwardly toward the wall 4 far enough so that its upper surface 14 will engage the circumferential surface of the rim of the improperly loaded cartridge when it is lowered from its uppermost position in engagement with the flanges 6 and 7 to prevent the loading of any more cartridges into the magazine. The engagement of the surface 14 with the rim of the offending cartridge will prevent the lowering of said cartridge far enough to permit loading another cartridge or will resist such lowering sufficiently to indicate to the person loading the magazine that something is wrong so that he can remove the top cartridge or reload it in the proper manner. When the cartridges are loaded properly in the magazine A as shown in Fig. 3, the spring finger 12 slides over the relatively fiat smooth bases of the cartridges as they are lowered and does not interfere with the manual loading.

It is preferable to provide suitable means to prevent catching by the spring finger 12 of the rim of the first cartridge inserted into the magazine. As herein shown, the sheet metal platform 8 has downwardly extending wall portions and 16 parallel to the

walls

3 and 4. The front of the platform 8 may be shaped to press the finger 12 rearwardly beyond the interior surface of the end wall 3 or far enough so that it will not catch the rim of the cartridge engaging said platform, or the platform may be shaped to hold said cartridge out of contact with the wall 3 in a position where it will not catch on the finger. As herein shown, the wall portion 16 of the magazine platform 8 is provided with a pair of parallel rectangular tongues or runners 17 which are spaced apart a distance greater than the width of the finger 12. Said tongues and the portion 1.5 of the platform 8 may slidably engage the

walls

3 and 4 as the platform is moved vertically. When the platform is raised above the top of the spring finger 12 as shown in Figs. 1 and 2, the finger engages the portion 16 between the tongues 17. Each of said tongues has a reversely bent upper end portion 18 projecting above the generally horizontal upper surface of the platform 8 and having a cartridge-engaging front face forwardly of the rear or outer surface of the wall portion 16 to prevent movement of the rear face of the cartridge behind said outer surface, whereby the finger 12 cannot catch the rim of the cartridge on the platform 8. A single tongue with a width equal to that of the platform 8 may be employed instead of the spaced tongues 17 to prevent such catching of the firstentered cartridge, but the spaced tongues are preferred.

Figure 5 shows a single-row box magazine A which is exactly the same as the magazine A except that the spring finger 12 and the lug 13 are replaced by a stationary lug or projection 12a having a width equal to that of the finger 12. The

elements

3a, 4a, 6a, 8a, 9a, 15a, 16a, 17a and 18a of the magazine A are substantially the same as the

elements

3, 4, 6, 8, 9, 15, 16, 17 and 18 of the magazine A. The tongues 17a of the magazine platform move on opposite sides of the projection 12a as the platform 8a is elevated by the spring 9a toward the stop member or magazine lip 6a. The resilient spring 9a normally holds the uppermost cartridge 5 in a substantially horizontal discharge position against the lip 6a. The projection 12:: has an upper surface 19 in the form of a ledge for catching the rim 10 of the last-entered cartridge 5 as it is lowered from said discharge posi tion whenever the rim of said cartridge is behind the rim 10 of the next lower cartridge. The surface 19 of the projection 12a is below said discharge position and, like the surface 14 of the finger 12, is preferably spaced therefrom a distance not substantially greater than the maximum diameter of the cartridge so that improper loading of a cartridge will be indicated before another cartridge can be loaded into the magazine. When a cartridge 5 is moved downwardly past the projection 1.2a, the total clearance may be not greater than the thickness of a rim 10 so that the uppermost cartridge cannot clear the projection when its rim is caught behind the rim of a lower cartridge. However, such projection may indicate improper loading even if such clearance is relatively large, particularly if conventional loading methods are empolyed wherein each cartridge is pressed rearwardly toward the wall 3a as it is lowered in the magazine. Manual pressure in loading will force a misloaded cartridge into engagement with the projection 12a to indicate the improper loading.

Figures 6 and 7 show a modified single-row sheet-metal box magazine A according to the present invention. Said magazine is similar to the magazine A and has parallel side walls 1b and 2b and substantially parallel end walls 3b and 4b defining a receptacle of rectangular horizontal cross section for receiving a series of rimmed cartridges 5b similar to the cartridges 5. The side walls 1!) and 2b are provided at their upper ends with horizontal inturned lips or stop

flanges

6b and 7b to limit upward movement of the cartridges 5b. The cartridges are pressed upwardly against the magazine lips by a magazine platform and a spring as in the magazines A and A. The rear end wall 3b is cut to provide a rectangular opening 11b and an integral rectangular resilient spring finger 12b which functions like the finger 12 of the magazine A to prevent improper loading of the magazine. If desired the entire magazine box may be heat-treated to provide the finger 12b with the desired resiliency.

Figures 8 to 10 show a double-staggered-row sheetmetal box magazine A of a type suitable for use on highpowered semi-automatic rifles and various other firearms. The amagazine A includes

parallel side walls

20 and 21 and substantially

parallel end walls

22 and 23 which define receptacles of rectangular cross section for receiving two rows of cartridges 24. The

side walls

20 and 21 are provided with inturned lips or stop

flanges

25 and 26, respectively, for limiting the upward movement of the artridges in the magazine. A laterally stepped generally rectangular, sheet-metal magazine platform or follower 27 is mounted for movement vertically in the magazine A and is biased upwardly by a resilient sheet metal spring 28. The platform 27 engages the first cartridge 24 that enters the magazine A and holds the last-entered cartridges 24 in a predetermined discharge position against one of the

stop members

25 and 26, for example as shown in Figs. 8 and 9. The top edge of the front end wall 23 is spaced below the stop members to permit forward movement of the uppermost cartridge 24 from its discharge position out of the magazine, but said end wall prevents forward movement of earlier-entered cartridges from their storage positions in the magazine.

The rear end wall 22 is provided with a rectangular opening 29 halfway between the

side walls

20 and 21 and below said discharge position and with a rigid yieldable finger 12c of substantially uniform width and length that projects through said opening. The finger 12c is mounted on a pivot pin 30 for swinging movements on the end wall 22 and is biased into engagement with the cartridges 24 by a resilient rectangular sheet-metal leaf spring 31 which is welded or othewise secured at its lower end to the wall 22. The opposite end portions of the assumes pin 300 project through alined circular openings in a pair of integral lugs 32 which are bent outwardly at opposite sides of the opening 29 as shown in Fig. 9. The upper end of the spring 31 is spaced from the wall 22 and engages a lower portion 33 of the member 12c as shown in Fig. 8 yieldably to resist movement of an upper portion 34 of said member away from the cartridges 24. The upper portion 34 has a hat horizontal upper surface 35 for catching the rim of an improperly loaded cartridge.

The stepped magazine platform 27 is shown herein as being formed of a single piece of sheet metal of uniform thickness and is provided with front and rear downwardly-turned

lateral flanges

36 and 37 at its opposite ends. The sheet metal of the platform 27 is bent longitudinally throughout its length to form a lower portion 38 extending between the

flanges

36 and 37 and extending the full width fthe platform and an upwardly projecting inturned supporting portoni 39 that terminates substantially midway between the side edges of the platform.

Like the magazine previously described, the magazine A may be provide with tongues to prevent catching of a cartrdige that engages the magazine platform. As herein shown, the flange 37 is provided with a pair of

rectangular tongues

40 and 41 which are spaced apart a distance greater than the width of the finger 12c and which move on opposite sides of the finger as the platform is moved past the upper surface 35 of said finger. The

tongues

40 and 41 project a short distance above the upper surface of the

portions

38 and 39, respectively, to limit rearward movement of the cartridges 24 on the magazine platform 27. The tongue 40 has a front face which projects forwardly of the outer finger-engaging surface of the flange 37 for engaging the lowermost or first-entered cartridge on the portion 38 and for holding the base of said cartridge forwardly of the upper surface 35 as the lower surface of said base moves past said upper surface whereby said first-entered cartridge does not catch on the finger 120.

Each of the high-powered cartridges 24 shown herein is of a standard type and includes a cartridge case 42 of circular cross section that increases in diameter towards its base and a bullet 43 coaxial with said case. The cartridge case 42 has a circular rim 44 that projects radially beyond the general body of the case substantially as shown in Fig. 8 and has a substantially flat bottom surface with a centrally located primer 45 substantially flush with said surface.

The double-staggered-row magazine A is loaded manually in a conventional manner by slipping each cartridge 24 horizontally under one of the

magazine lips

25 and 26, pushing the cartridge rearwardly as far as possible until its rim 44 engages the tongue 40 or the rim of another cartridge, and pushing the cartridge downwardly to permit entrance of another cartridge. To be loaded properly the rim 44 of each cartridge must lie behind the rim 44 of a later-entered cartridge directly above it and behind the rim 44 of a later-entered cartridge diagonally above it. If each cartridge 24 is positioned with its rim 44 ahead of the rim of the next adjacent cartridge diagonally above it as shown in Figs. 8 and 9, the rim of a cartridge will not catch on the rim of a lower cartridge as the former cartridge is moved horizontally out of the magazine from its discharge position in engagement with the magazine lip.

The magazine A is of a width to receive two rows of cartridges 24. The portion 39 of the magazine platform extends above the portion 38 a distance corresponding substantially to the radius of each cartridge 24 so as to support the two rows of cartridges in such a manner that each cartridge in a row is vertically aligned with the other cartridges in said row and engages two other cartridges as shown in Figs. 8 and 9.

The yieldable finger 120 is biased against the base of each cartridge as said cartridge passes the upper surface 35 and slides along such base without catching so long as the cartridges are properly loaded with the rim of each cartridge ahead of the rim of the next adjacent cartridge diagonally below it. The rim 44 of a cartridge engaging the upper portion 34 of the finger He holds said finger so that it cannot catch the rim of the next adjacent cartridge diagonally above it provided that the latter rim is forwardly of the former rim. However, if the magazine is loaded improperly and the rim 44 of the upper or last-entered cartridge 24 is behind the rim of the earlierentered cartridge, as shown in Fig. 10, the upper end of the finger projects inwardly beyond the inner surface of the rear end wall 22 a distance substantially greater than the axial thickness of a rim 44 and sufficiently so that the upper surface 35 of said finger engages the rim 44 of the last-entered cartridge to prevent lowering thereof and to indicate that the latter cartridge is loaded improperly.

As shown in Figs. 8 and 9, the magazine A is partially loaded and contains six cartridges, the uppermost or last-entered cartridge being yieldably held in a predeter mined discharge position in engagement with the stop member 25 and the earlier-entered cartridges being held in storage positions between the

end walls

22 and 23. The cartridge-rim-engaging surface 35 is below the uppermost cartridge in said discharge position and is preferably spaced therefrom a distance not substantially greater than the radius of each rim 44 so that an improperly loaded cartridge 24 will catch on the finger 120 before another cartridge is loaded into the magazine. As herein shown, the surface 35 is adjacent the axis of an intermediate cartridge directly below the uppermost cartridge and adjacent the upper surface of the rim of a cartridge diagonally below said intermediate cartridge.

A fairly solid yieldable finger 12c is employed in the double-row magazine A shown herein to insure that the finger will not twist during use, but it will be understood that a thin sheet-metal spring finger of the type shown in Figs. 1 to 4 or Figs. 6 and 7 or a stationary projection of the type shown in Fig. 5 may also be employed in said magazine.

Each of the magazines A, A, A and A may be made with the same relative sizes and shapes as shown in Figs. 1 to 9 which are drawn substantially to scale, but it will be understood that the magazines may also have various other shapes and sizes. The upper surface of each of the

detents

12, 12a, 12b and 120 which catches the rim of an improperly loaded cartridge is preferably spaced from the uppermost or discharge position of a cartridge a distance not substantially greater than the vertical distance between the axis of the last-entered cartridge and the axis of the next-to-last-entered cartridge, but it will be apparent that many of the advantages of each detent will be obtained if it is located further from the discharge and receiving end of the magazine and closer to the bottom of the magazine.

It is to be understood that, in accordance with the provisions of the patent statutes, variations and modifications of the specific devices disclosed herein may be made without departing from the spirit of the invention.

Having described my invention, I claim:

1. A magazine having front and rear end walls and parallel side walls connecting said end walls to define a receptacle for a series of cartridges, each having a body of generally circular cross section and a base with a rim that projects radially outwardly beyond said body, said magazine having a discharge end and a lip inturned from each of said side walls at said discharge end, a follower in said receptacle for engaging the first-entered cartridge mounted for movement toward and away from said discharge end, spring means biasing said follower in a direction toward said discharge end, said follower and spring means providing means for yieldably holding one of said cartridges in a predetermined discharge position against one of said lips and for holding a row of said cartridges in storage positions inwardly of said discharge position wherein the rim of each cartridge in a storage position is rearwardly of the rim of the next adjacent cartridge nearer said discharge position and in engagement with the body of said adjacent cartridge, said lips preventing movement of a cartridge in said discharge position in said firstmentioned direction out of the magazine, said side walls providing means for holding the cartridges in rows when the magazine is loaded, said end walls being spaced apart a distance slightly greater than the length of the cartridges to permit limited axial movement of the cartridges between said end walls, said magazine being constructed so that the annular front face of the rim of a cartridge in a storage position within said receptacle would not engage any portion of the magazine if that cartridge were moved a short distance axially from a position nearest the rear end wall to a position nearest the front end wall, the front and rear end walls being spaced apart a distance greater than the axial length of each cartridge plus the axial thickness of the rim thereof so that the magazine may be improperly loaded by placing the rim of a cartridge in a position rearwardly of the rim of the next adjacent cartridge closes to said discharge end, whereby the rim of one cartridge will catch the rim of the adjacent improperly-loaded cartridge when the latter cartridge is moved forwardly from the discharge position and will interfere with feeding of the cartridge from the magazine, said magazine being open forwardly of said discharge position so that each cartridge that arrives at a discharge position in engagement with the lip of a side wall may be fed forwardly in a direction generally perpendicular to the direction of movement of said follower and past the front end wall out of this magazine and so that cartridges may be moved into the magazine in the opposite manner to load the magazine, the outer edge of the front end wall being spaced at short distance inwardly from the nose of a cartridge in said discharge position so as not to interfere with axial movement of said last-named cartridge into or out of said discharge position, said last named distance being measured from said cartridge in a direction inwardly from said discharge position toward the storage position, the front end wall preventing axial movement of the next adjacent cartridge out of the magazine, an inwardly projecting finger carried by the rear end wall and having a cartridge-baseengaging portion spaced inwardly of said discharge position and normally projecting inwardly from said rear wall a distance greater than the axial thickness of the rim of each cartridge to provide means for catching the rim of the last-entered cartridge as that cartridge is moved from said discharge position to a storage position whenever that cartridge is improperly loaded with its rim rearwardly of the next adjacent cartridge inwardly of that cartridge, said finger permitting each properly-loaded cartridge to move from said discharge position to a storage position and in the opposite direction, said finger having a cartridge-engaging face inclined away from said discharge end so that the finger will not catch the rims of cartridges moving from storage positions toward said discharge end.

2. A magazine as defined in claim 1 comprising a double-staggered-row box magazine having side walls spaced apart a distance substantially greater than the diameter of said cartridges and less than twice said diameter so that the cartridges may be loaded into the magazine in two parallel rows, said follower engaging the earliest-entered cartridge in each row and holding the cartridges in staggered relation so that when the magazine is fully loaded each cartridge in a row is aligned with the other cartridges in a row and engages adjacent cartridges in both rows, said finger being located for engagement with cartridges in both rows to provide means for indicating improper loading of a cartridge in either row.

3. A magazine having front and rear end walls and parallel side walls connecting said end walls to define a receptacle for a series of cartridges, each having a body of generally circular cross section and a base with a rim that projects radially outwardly beyond said body, said magazine having an upper discharge end and a lip inturned from the top of each of said side walls, a follower in said receptacle for engaging the lowermost firstentered cartridge mounted for upward and downward movement toward and away from said discharge end, spring means biasing said follower upwardly toward said discharge end, said follower and spring means providing means for yieldably holding one of said cartridges in a predetermined uppermost discharge position against one of said lips and for holding a row of said cartridges in storage positions below said discharge position wherein the rim of each cartridge is forwardly of the rim of the next adjacent lower cartridge and in engagement with the body of said adjacent cartridge, said lips preventing upward movement of a cartridge out of the magazine, said side walls providing means for holding the cartridges in rows when the magazine is loaded, said front and rear end walls being spaced apart a distance only slightly greater than the axial length of each cartridge plus the axial thickness of the rim thereof so as to limit axial movement of the cartridges while permitting improper loading of the cartridges whereby the rim of the uppermost cartridge is rearwardly of the rim of the next adjacent lower cartridge and will catch the rim of the latter cartridge to interfere with feeding of said cartridge, the top front portion of the magazine being open and the top edge of the front end wall being spaced below said lips a distance slightly greater than the diameter of the cartridges so as not to interfere with feeding of the uppermost cartridge forwardly out of the magazine, said front end wall preventing forward movement of the next adjacent lower cartridge out of the magazine, an inwardly projecting finger carried by the rear end wall and having a cartridge-base-engaging portion spaced below said lips a distance slightly greater than the diameter of said cartridges so as to be located normally contiguous to the base of the cartridge just below a cartridge in said discharge position, said last-named portion projecting for wardly from said rear wall a distance greater than the axial thickness of the rim of each cartridge to provide means for catching the rim of the uppermost cartridge as the latter is moved downwardly from said discharge position to a storage position whenever that cartridge is improperly loaded with its rim rearwardly of the next adjacent lower cartridge, said finger permitting each properly-loaded cartridge to move downwardly and upwardly toward and away from said discharge position, and means carried by said follower for positioning the lowermost cartridge and said finger so that the finger does not catch the lowermost cartridge as it is lowered to a storage position within the magazine.

References Cited in the file of this patent UNITED STATES PATENTS 768,842 Bruce Aug. 30, 1904 807,790 Taylor Dec. 19, 1905 875,209 Prinke Dec. 31, 1907 1,056,057 Randall Mar. 1.8, 1913 1,331,155 Johnson Feb. 17, 1920