US2083427A

US2083427A - Burring tool

Info

Publication number: US2083427A
Application number: US86500A
Authority: US
Inventors: Brunner Albert
Original assignee: Wagner Electric Corp
Current assignee: Wagner Electric Corp
Priority date: 1936-06-22
Filing date: 1936-06-22
Publication date: 1937-06-08
Anticipated expiration: 1954-06-08

Description

A. BRUNNER 'BURRING TOOL June 8, 1937.

Filed June 22, 1936 18 I7 F|G.l.

IN V EN TOR. BRUNN ER ATTORNEY.

Patented June 8, 1937 UNITED srA'rEs 2,083,427 BURRDIG r001.

Albert Brunner, St. Louis, Mo., assignor to Wagner Electric Corporation, St. Louis, Mo., a corporation of Delaware Application .l'une 22, 1936, Serial No. 86,500

13 Claims.

My invention relates to tools and more particularly to portable tools for smoothing the rough or burred edge of a drilled or punched opening.

In the manufacture of certain types of cylinder and piston combinations it is necessary to provide the cylinder wall with a hole or aperture for the ingress and egress of fluid. This hole is generally formed by drilling from the ex terior of the cylinder to the interior and consequently the inner edge of the hole is left with a rough sharp edge commonly known as a burr. Since this edge is on the interior of the cylinder, the rough edge cannot be conveniently reached and removed by an ordinary punch. If the edge is not removed, it will injure the packing of the piston during the reciprocation of the pis ton past the opening, a condition which is undesirable. In accordance with my invention, I have devised a portable burring tool by means of which the sharp inner edges of the type of hole above referred to may be easily and quickly made smooth.

One of the objects of my invention is to produce a. burring tool which is especially adapted for smoothing the inner edge of a drilled hole in a cylinder Wall. I

Another object of my invention is to produce a burring tool that is simple, inexpensive, easily operable, and adapted for use with cylinders of different diameters and constructions.

Other objects of my invention will become apparent from the following description taken in connection with the accompanying drawing showing three embodiments thereof.

In the drawing Figure 1 is a view showing one form of my burring tool being employed for smoothing the inner edge of a drilled hole in a cylinder; Figure 2 is an enlarged cross-sectional view taken on the lines 22 of Figure '1 showing parts of the tool just prior to the tool being operated; Figure 2A is an enlarged crosssectional view showing how the burring operation is performed; Figure 3 is a View of a modified construction; and Figure 4 is a view of another modified construction for use on a different type of cylinder construction.

Referring to Figures 1, 2, and 2A, the burring tool shown comprises two cooperating levers l and 2 pivoted together at an intermediate point by means of a pivot pin 3. The rear ends of the levers are so formed as to provide handles 4. and 5 for actuation by the hand of an operator and the forward ends of the levers are formed so as to provide straight arms 6 and 1, arm 6 being provided with a projection 8 acting as a stop member to limit the extent of inward movement of the arms. The extreme end of arm I has formed therein a suitable opening into which is press fitted a punch member 9 provided with a conical portion [0 and an upstanding projection II, the portion between the conical portion and the projection being so formed as to provide an annular curvedsurface for performing the burring operation of the tool. This punch member is constructed of a suitable hardened material, as. for example, hardened tool steel, in order that it may properly perform its function over a considerable period of time. The extreme end of arm 6 is also provided with a suitable opening into which is press fitted an abutment member [2 which is preferably made from aluminum although other soft metals and materials which will not injure a smooth surface may be employed. The outer surface l3 of member I2 is curved as shown, the curvature being such that the point of contact of the abutment against asupport will aways be in alignment with the axis of the punch within the limits for which the tool is designed.

Inorder to normallymaintain arms 6 and 1 in closed position where arm engages projection 8, the handle portion 4 is provided with a projecting lug l4 and handle 5 is provided with a similar projecting lug i5 and positioned between, these lugs is an expansion spring [6 normally biasing handles 4 and 5 apart and, consequently, biasing arms 6 and I together. One end of the spring is adapted to fit over projection Hi and the other end over projection l5 in the manner shown.

The inner end of arm 1 adjacent the pivot point of the lever has formed thereon an upstanding projection l'! and threaded through this projection is a screw l8 forming an adjustable stop for engaging the end of a cylinder and predetermining the distance the punch member on arm I can be inserted into the end of the cylinder.

I have shown my tool as being used for burring or smoothing the inner edge of what is known as a compensating port in a master cylinder construction used in hydraulic brake systems but it is to be understood that this is solely for the purpose of illustration as the tool may be as readily employed for burring the edges of openings in other types of cylinders or articles. -In the cylinder construction shown cylinder I9 is formed with a compensating port 20 which is employed for placing the interior of the cylinder in communication with the reservoir positioned directly above the cylinder and enclosed by wall 2!, only a portion of which is shown. This compensating port is produced by a drilling operation from the reservoir or exterior side of the cylinder and, as a result thereof, the inner end of the compensating port or opening 20 is left with a rough sharp edge commonly referred to as a burr and shown exaggerated at 22 in Figure 2. When the piston and piston packing cup, which operate in cylinder I9 are positioned in the cylinder, their normal retracted position is suchthat they are positioned tothe rear of compensating port 28. It is'thus seen that if the sharp rough edge 22 is not removed after the drilling operation is performed, it will cause the packing to be cut during reciprocationiofi...

openingili. This point is determined by proper adjustment of set, screw i8 which abuts against the end of the cylinder when arms 6 and 1 are inserted in the bore thereof. The position of punch .9 with respect tohole 2|] when the arms are initially inserted in the cylinder is best shown ,in Figure 2. To now perform the burring operation'or the smoothing of the sharp edge 22, handles 4 and 5 of thetool are forced together by the hand ofthe operator, thereby causing projection H to enter opening 20 and abutment I2 to engagethe opposite wall of the cylinder and at a point in-alignment with the axis of punch member 9. Pressure onthe handles'will now cause the annular curved surface between projection-l I" and the conical portion ID; tobe Referring to Figure 3, I have shown a slightly modified-=constructionin which the punch is forced into engagement with the *rough sharp edge 22 by means of spring pressure instead of byha-nd pressure. Leversiiii and24 are so formed as to cross over each other andare pivoted together at this point by means of pivot pin 25. The levers are'forme'd

withhandle portions

26 and 21 and with forwardly extending

arms

28 and 29. Arm 28' carries punchmember 9' atqits,

outer end andarm 29 carries the abutment-member I2 at its outer end; Arm 28 is also provided with a projection carrying the adjustable screw l8. Theinner surface of arm 28 is pro vided with a socket 30 and the'inner surface of "arm 25! is provided'with a similar socket 3|, these sockets being adapted to receive the ends ofan expansicn coil spring '32, biasing arms 28 and--29 apart. In order to limit the extent of separationcf the arms, arm 29 has pivoted thereon amember 33 provided with a slot 34 which receives a stop pin 35 carried by arm 28. Slot'34 is of such length that it permits the arms to be moved together sufficiently that they maybe inserted in the cylinder.

In performing the burring operation with'this tool,

handles

26 and 21 are forced together by the hand of the operator, thus moving

arms

28 and 29"toward each other sufficiently that the arms may be inserted in the cylinder and to a point determined by the adjustable screw I8. With punch 9' now positioned directly below porthole 20, the hand ofthe operator is permitted to quickly-release the handles, whereby spring 32 will rapidly expand and force the annular curved ing off the burred edge.

surface of punch member 9 into engagement with the sharp edge with sufficient force to break for use with a type of cylinder construction which "i'sinserted into a reservoir that completely surrounds the entire cylinder including its open end.

Levers

36 and 31 are formed to cross over thereon a small projection 46'. The inner surface of arm carries the projecting portion 41 and adjustable screw 48. V

In the operation of this tool, arm 42 is posi tioned in the bore of cylinder 49 and arm 44 is positioned on the exterior of the cylinder and projection 46 on abutment member is placed in opening 50, this operation being quickly performed by the proper positioning of set screw 48 which is adapted to abut the inner end of slot 5| formed in the end of the cylinder. The actual I burring operation is now. performed by the

operator forcing handles

39 and 40 together by his hand, thus causing

arms

42 and 44 to be moved toward each other forcing the annular curved surface of punch member 43 into engagement with the rough edge o-fth'e drilled hole and smooth- The tool is removed by releasing-the pressure on the handles whereby spring 4| will separate

arms

42 and 44 suff ciently that the projection 46 can be removed from hole 50 and the arms withdrawn.

It is to be noted that the tools shown in Figures 1 and 3 can be used with the type of cylinder shown in Figure-4 if such is desired. The adjustable stop screw employed on all the tools for engagement with the end of the cylinder is not a necessary feature but it has been found to be very useful in speeding up the work when a large number of the same kind of cylinders are being operated upon since the set screw may be given an initial setting and the operator will know that when'it is in engagement with the end of the cylinder, the punch member is beneath the hole to be burred. As a substitute for the adjustable stop, the arm carrying the punch may be provided with marks as shown at 5| in Figure 1. When the proper mark for the cylinder being worked upon is even with the end of the cylinder, the

claim as new and desire to secure by'Letters Patent of the United States is:

1. In a tool for smoothing the rough inner edge of an opening in the wall of a cylinder or like article, a pair of relatively movable members, an element non-rotatably carried'by one member and having an annular surface adapted to engage the rough edge of the opening, and hand-operated means for moving the members relatively to each other whereby one of the members will abut a wall of the cylinder and the annular surface of the element on the other member will be forced into engagement with the rough edge of the opening to thereby smooth said edge by direct pressing action.

2. In a burring tool for smoothing the rough edge of a drilled opening in a member, a pair of arms pivoted together, a member provided with an annular curved surface and non-rotatably carried by the free end of oneof the arms, and means for moving the arms in opposite directions to cause one arm to engage an abutment surface and the curved surface of the member on the other arm to be forced against the edge of the opening to thereby smooth said edge by direct pressing action.

3. In a tool for smoothing the rough edge of an opening, a pair of cooperating arms pivoted together, an element non-rotatably carried by one of said arms adjacent its free end and having an annular curved surface, an element carried by the other arm for abutting against a support, and manually-operated means for moving the arms in opposite directions whereby the curved surface of the element can be forced into engagement with the rough edge of the opening and the other element can be forced intoengagement with a support to thereby cause the curved surface to smooth the edge by direct pressing action.

4. In a tool for smoothing the rough inner edge of a drilled opening in the wall of a cylinder or like article, a pair of levers pivoted together and forming a pair of handles and a pair of arms, and a burring element carried by one of the arms for engagement with the rough edge of the opening When the handles are operated by the hand of an operator to cause the other arm to engage a portion of the cylinder wall.

5. In a tool for smoothing the rough inner edge of a drilled opening in the wall of a cylinder, a pair of levers pivoted together and formin a pair of handles and a pair of arms, said arms adapted to be moved in opposite directions by the actuation of the handles by the hand of an operator, an element having an annular curved surface and carried by one of the arms for engaging the rough edge, and an abutment element carried by the other arm for engaging a portion of the cylinder.

6. In a tool for smoothing the rough inner edge of a drilled opening in the wall of a cylinder, a pair of levers pivoted together and forming a pair of handles and a pair of arms, said arms adapted to be moved in opposite directions by the actuation of the handles by the hand of an operator, an element carried by one of the arms and having a surface for engaging and smoothing the rough edge, an abutment element carried by the other arm for engaging a portion of the cylinder, and a spring for biasing the handles apart.

7. In a tool for smoothing the rough inner edge of a drilled opening in the wall of a cylinder, a pair of levers pivoted together and forming a pair of handles and a pair of arms, said arms adapted to be moved in opposite directions by the actuation of the handles by the hand of an operator, an element having a surface for engaging and smoothing the rough edge and carried by one of the arms, an abutment element for engaging a portion of the cylinder and carried by the other arm, a spring for biasing the handles apart, and a stop carried by one of the arms and cooperating with the other arm for maintaining the arms in predetermined spaced relation.

8. In a tool for smoothing the rough edge of an opening through a member, a pair of levers pivoted together in crossed relation and comprising a pair of arms and a pair of handles, a member on the end of one of the arms and provided with a surface for engaging and smoothing the rough edge, a spring for forcing the arms apart, and means for limiting the extent of separation of the arms when the handles are freed by the operator.

9. 'In a tool for smoothing the rough edge of an opening through a member, a pair of levers pivoted together in crossed relation and compris ing a pair of arms and a pair of handles, a mem ber on the end of one of the arms and provided with a surface for engaging and smoothing the rough edge of the opening, and a coil spring for normally maintaining the arms in spaced relation.

10. In a tool for smoothing the rough edge of an opening through a member, a pair of levers pivoted together in crossed relation and comprising a pair of arms and a pair of handles, a member on the inner surface of the end of one of the arms and provided with an annular curved surface for engagement with the rough edge of the opening, a'projection on the inner surface of the other arm and adapted to project into the end of the opening opposite the one provided with the rough edge, and a coil spring for normally maintaining the arms in spaced relation.

11. In a tool for smoothing the rough inner edge of a drilled opening in the wall of a cylinder or like article, a pair of levers pivoted together and forming a pair of handles and a pair of arms, a burring element carried by one of the arms for engagement with the rough edge of the opening when the handles are operated by the hand of an operator to cause the other arm to engage a portion of the cylinder wall, and means carried by one of the arms and adapted to cooperate with the end of the cylinder for indicating the distance that the arm carrying the burring element should be inserted in the cylinder to be in an operative position.

12. In a tool for smoothing the rough inner edge of a drilled opening in the wall of a cylinder or like article, a pair of levers pivoted together and forming a pair of handles and a pair of arms, a burring element carried by one of the arms for engagement with the rough edge of the opening when the handles are operated by the hand of an operator to cause the other arm to engage a portion of the cylinder wall, and an adjustable stop carried by one of the arms and adapted to engage the end of the cylinder for predetermining the distance that the arm carrying the burring element may be inserted in the cylinder.

13. In a tool for smoothing the rough inner edge of a drilled opening in the Wall of a cylinder, a pair of levers pivoted together and forming a pair of handles and a pair of arms, said arms adapted to be moved in opposite directions by the actuation of the handles by the hand of an operator, an element carried by one of the arms and having a surface for engaging and smoothing the rough edge, an abutment element carried by the other arm for engaging a portion of the cylinder, and an adjustable stop carried by one of the arms for engagement with an end surface of the cylinder.

ALBERT BRUNNER.