US2453222A

US2453222A - Rotary head for sanding machines

Info

Publication number: US2453222A
Application number: US789921A
Authority: US
Inventors: Jack C Hammontree
Original assignee: Individual
Current assignee: Individual
Priority date: 1947-12-05
Filing date: 1947-12-05
Publication date: 1948-11-09
Anticipated expiration: 1965-11-09

Description

Nov. 9, 1948.

J; C. HAMMONTREE ROTARY HEAD FOR SANDING MACHINES 2 Sheets-Sheet I Filed Dec. 5, 1947 FIG-3 INVENTOR. J. c. HAMMONTREE F/GZ Attorneus Nov. 9, 1948- J. c. HAMMONTREE ROTARY HEAD FOR SANDING MACHINES 2 Sheets-Sheet 2.

Filed Dec. 5, 1947 INVENTOR. J. C. HAMMON TREE FIG. /0

Attorneys Patented Nov. 9, 1948 UNITED STATES PATENT OFMCE 4 Claims.

My invention relates to a power operated rotary head for sanding machines.

An important object of the invention is to provide a head for sanding machines, wherein the sand paper sheet or disc can be changed or adjusted Without disassembling the parts of the head or removing any screws or the like.

A further object of the invention is to provide a sanding head wherein the sand paper is clamped between two members and held in place by spring tension, thus eliminating the need for attaching screws, and providing a full circular sanding surface.

A further object of the invention is to provide a sanding head adapted to be mounted upon the armature shafts of portable or stationary motors, and which is extremely simplified in construction, durable and inexpensive to manufacture.

Other objects and advantages of the invention will be apparent during the course of the following description.

In the accompanying drawings, forming a part of this application, and in which like numerals are employed to designate like parts throughout the same;

Figure 1 is a central vertical section through the sanding head embodying the invention, and

showing the same mounted upon the armature.

shaft of an electric motor, parts in elevation.

Figure 2 is a plan view of a sanding sheet or disc removed.

Figure 3 is a side elevation of a locking sleeve removed.

Figure 4 is an end elevation of the same.

Figure 5 is an end elevation of a sanding disc.

Figure 6 is a side elevation of the same.

Figure '7 is an elevation of a clamping disc.

Figure 8 is a side elevation of the same.

Figure 9 is a fragmentary side elevation of the clamping disc, taken at right angles to Figure 8.

Figure 10 is a fragmentary end elevation of the clamping disc.

In the drawings, where for the purpose of illustration is shown a preferred embodiment of the invention, the numeral l5 designates an electric motor, having an armature shaft l6, including a reduced end extension l1.

Detachably mounted upon the reduced extension l1, and rigidl secured thereon, by means of a set-screw I8, is a sanding disc I 9, including a spindle 20. The spindle is cylindrical and includes a reduced screw-threaded extension 2| forming a lateral annular shoulder 22, and having a central axial bore or opening 23 to receive the extension I1. The spindle 20 is disposed at the center of the disc H] which is circular, rigid and fiat. The disc I9 is rounded at its peripheral edge 24. The disc I9 is integral With the spindle 20, and disposed at right angles to the same. The top of the set-screw i8 does not project above the outside diameter of the extension 2!.

Mounted upon the screw-threaded extension is a locking sleeve 25. This locking sleeve is internally screw-threaded and cylindrical at its end adjacent to the shoulder 22 as at 26. The locking sleeve 25 includes diametrically oppositely disposed projections or pins 21, which project radially from the sleeve. The end 23 of the sleeve 25 remote from the shoulder 22 is hexagonal, as shown. The outer end of the sleeve 25 is adapted to engage the shoulder 22, when the sleeve is in a locked or clamping position. In such position, the set-screw I8 is disposed beyond the opposite end of the sleeve 25, as shown.

v with, and disposed at the center of the disc The sleeve 30 is cylindrical and tubular and. engages over the spindle 20 and cylindrical end 25 of sleeve 25, as shown. The sleeve 30 is slidable upon the spindle 20 and end 26. l

The sleeve 30 has an inner annular end 3i having diametricall oppositely arranged cylindrically curved radial recesses 32, adapted to form seats for the pins 21 of sleeve 25, when such sleeve is in the locking position. Adjacent to the recesses 32 and spaced angularly slightl therefrom, Figure l0, and formed in the end 3| and side wall of the sleeve 3!] are spiral slots 33. which terminate near the longitudinal center of the sleeve to, as shown. The pins 2! are adapted to slidably enter the spiral slots 33 when the sleeve 25 is in the unlocked position. The forward face of the clamping disc 29 is slightly concave, as shown at 34, so that onl a relativel narrow circumferential portion 35 of the disc 29 engages the inner flat surface of the sanding disc iii. The disc 29 is somewhat resilient due to its concavity.

A circular sandpaper sheet 36, or the like, having a scalloped marginal edge, forming triangular teeth 31, is mounted upon the forward face of the sanding disc 19. The triangular teeth i! are folded around the rounded edge 24 and arranged between the inner face of the disc 19 and the narrow annular portion 35 of the clamping disc 29. The teeth 31 are provided to prevent wrinkling of the sandpaper sheet 36. edge 24 prevents possible cutting of the sandpaper The roundedsheet. The entire forward or working face of the sanding disc I9 is covered by the sandpaper sheet 36, as shown.

In use, the sanding head is applied to the armature shaft of the motor, as shown in Figure l. The set-screw i8 is tightened, and the head will rotate with the armature shaft. With a sandpaper sheet 36 in place, as in Figure 1, the locking sleeve is screwed to the left, Figure 1, until the shoulder 22 is engaged. The ins 121 are 'now engaged in the recesses 32 of the sleeve 30, and'the clamping disc 29 is locked in tight clamping engagement against the sanding disc l9, to secure the sheet 36 in place. The disc-29 is slightly resilient, as stated, and exerts a yielding force upon the scalloped edge of the sandpaper sheet.

When it becomes necessary to change the sandpaper sheet, it is unnecessary to disassemble the sanding head. A wrench or the like is applied to the hexagonal end 28 of locking sleeve 25, and the sleeve is unscrewed sufficiently for the ;.pins 2] to disengage from within the recesses 32 When this occurs the .sleeve 2st) ,is turned slightly upon its longitudinal axis, :until the pins 21 engagein the spiral slots 33, at the sleeve end 31. The sleeve 33 is now turned further, and due to the action of 1c pins 21 in thespiral slots 33, theisandng disc 29 may be readilyshifted axially to a position like that shown bydotted lines in Figure 1. Abundant space is thus provided to change the sandpaper sheet 36. The sleeve 36 is thenturned in the opposit-e direction, and the disc 29 will advance toward the clamping ,position. The pins '2 will leave thespiral slots .33, andare again engaged in the recesses 32. The locking sleeve is now tightened against the shoulder 22, and the new sandpaper sheet 36 is securely-clamped in .place.

It is to be understood that the form of the invention, herewith shown and describ.ed,is'to :be taken as a preferred example of the same, and that various changes in the shape, size and :arrangement of parts maybe resorted to. without departing from the spirit of the invention -or {the scope of the subjoined claims.

Having thus-described the invention, I claim:

l. A rotary head forsandi-ng machines including a motor having an armature shaft, such head comprising a sanding disc :mountednpon the armature shaft for rotation therewith, thesanding disc including a spindle having ascrew-threaded extension, clamping disc .slidably :monnted upon the spindle and adapted to engage the sanding disc and including asleeve havinglan end recess and spiral slot, and alocking sleevemountedupon the screw-threaded extension and including a part to alternately enga ein the end .recess and spiral slot.

2. A rotary head for sanding. machines. includsion and including projections to alternately en- .gage in the recesses and the spiral slots.

' 3. A rotary head for sanding machines includmounted upon the armature shaft for rotation therewith, said sanding disc including a cylindrical spindle having a screw-threaded extension provided withan opening to receive the armature shaft therein, the screw-threaded extension forming a shoulder, a clamping disc carried by the spindle and slidably mounted thereon and adapted to he clamped against the sanding disc and to move away from the same, the clamping disc being resilient and having a concave face adjacent to the sanding disc, the clamping disc including a cylindrical sleeve to engage over the spindle and having end recesses and spiral slots in itssides and extending through its end and an internally screwethreaded locking sleeve mounted upon the screw-threaded extension and including lateral pins to alternately engage in the recesses and spiral slots, the locking sleeve engaging against the shoulder when in the locking position.

4. A rotary head for sanding machines including a motor having an armature shaft, the head comprising a substant ally circular and flat sandingdisc mounted upon the armature shaft for rotation therewith, said sanding disc includinga spindle having a screw-threaded extension, ,a clamping disc mounted upon the spindle and slidable thereon and adapted to he vclamped against the sand ng disc the clampinr disc including a sleeve to engage over the spindle and having end recesses and spiral slots in its side wall, a locking sleeve mounted upon the screwthreaded extension and including pins to engage in the spiral slots and recesses, and a circular sanding .sheet having a scallopededge, the sanding sheet covering the forward face of the sanding disc and the scalloped edge being clamped between the sanding disc and clamping disc.

JACK C. HAMMONTREE,

,No references cited.