US3393442A

US3393442A - Squirrel cage blower puller device

Info

Publication number: US3393442A
Application number: US622569A
Authority: US
Inventors: Brewer Robert Keener
Original assignee: Brewer Robert Keener
Current assignee: ROBERT KEENER BREWER
Priority date: 1967-03-13
Filing date: 1967-03-13
Publication date: 1968-07-23
Anticipated expiration: 1985-07-23

Description

July 23, 1968 R. K. BREWER 3,393,442

SQUIRREL CAGE BLOWER FULLER DEVICE Filed March 13, 1967 FIG. 1

INVENTOR ROBERT K. BREWER k\ F a 4 BY WW- ATTORNEY United States Patent 3,393,442 SQUIRREL CAGE BLOWER PULLER DEVICE Robert Keener Brewer, 1800 De Charles St., Tyler, Tex. 75701 Filed Mar. 13, 1967, Ser. No. 622,569 3 Claims. (Cl. 29-259) ABSTRACT OF THE DISCLOSURE A substantially rectangular body having a circular socket in an edge thereof for accommodating the hub of the blower and a smaller bore coaxial with the socket for receiving the end of the shaft. There is a locking slot extending into the socket for receiving the partially unthreaded set-screw of the hub and a puller screw threaded into the body coaxial with the socket and bore to urge against the end of the shaft when the body is locked in position on the blower hub.

The present invention relates to a device for removing from a shaft a squirrel cage blower, pulley and the like having a hub secured to the shaft by a set-screw, more particularly, to such a device having a rectangular body which is relatively thin so as to be able to fit in the small clearance between the edge of the blower and the air-conditioner casing to fit the device over the blower hub and shaft end.

When a window air-conditioner unit has been in operation for several years, it may become necessary to replace the fan motor or to disassemble the unit for repairs. After such a unit has been in use for two to three years the motor shaft upon which the squirrel cage blower is mounted becomes rusty. As a result, the hub of the blower becomes extremely tightly secured to the shaft and considerable force is necessary to remove the blower from the shaft. In some instances it becomes necessary to cut off the motor shaft to remove the motor itself and then press the shaft out of the squirrel cage blower. This procedure, however, takes a considerable amount of time. In addition, the removal of the blower from the shaft is further complicated by the small clearance provided between the edge of the squirrel cage blower and the unit casing. In some instances this space is only about 1 /2 inches and it is extremely difficult even for a person to insert his hand in this space when he is considering removing the blower from the shaft.

It is therefore the principal object of the present invention to provide a novel and improved device for removing the squirrel cage blower from the motor shaft in a window air-conditioner unit.

It is another object of the present invention to provide a readily operable and effective device which can be easily used in limited and confined spaces for removing from a shaft squirrel cage blowers, pulleys and the like having a hub secured to the shaft by a set-screw.

The objects of the present invention are achieved and the disadvantages of the prior art are eliminated by the device according to the present invention which in one aspect may comprise a substantially rectangular block-like body having a pair of opposed faces with the thickness between the opposed faces being somewhat less that the diamter of the hub upon which the device is to be used. A bore or socket is provided on one edge of the body and has a diameter slightly greater than the diameter of the hub so as to receive the hub therein. The bore or socket opens to both of the opposed faces. A locking groove is formed in one of the opposed faces of body and extends into the bore. A second locking groove may be provided on the other opposed face. A set-screw is threaded into the body to engage the periph- 3,393,442 Patented July 23, 1968 eral surface of a hub received within the bore so as to grip the hub within the device. A second bore is provided in the body opening into the first bore and coaxial with the first bore for receiving the end of the shaft which may protrude outwardly of the hub. A puller screw is threaded into the body coaxial with the first and second bores and extending into the second bore when threaded into the body a portion of its length so as to engage the end of a shaft received therein. The puller screw may have a square head so that a wrench or the like can be used to turn the puller screw when the device is positioned over the hub.

To remove the blower from its shaft, the hub setscrew is unthreaded to a protruding position and the device is placed over the shaft end to receive the hub and shaft in the first and second bores respectively. The device is then slightly rotated so that the protruding hub set-screw is positioned Within the locking groove. The puller screw is then threaded into the body to engage the end of the shaft and to push the shaft inwardly away from the hub while the hub, by means of the set-screw, is retained in the device.

Other objects and advantages of the present invention will be apparent upon reference to the accompanying description when taken in conjunction with the following drawings wherein;

FIGURE 1 is a side elevational view of a portion of the interior of a window air-conditioner unit with the squirrel cage blower being partially cut away to illustrate the device of the subject invention in position on the hub;

FIGURE 2 is an overall perspective view of the device of the present invention together with a portion of the shaft and the hub which is received within the device;

FIGURE 3 is an end view of the socket end of the device of FIGURE 2; and

FIGURE 4 is a sectional view taken along the line 4-4 of FIGURE 3.

Proceeding next to the drawnigs wherein like reference symbols indicate the same parts throughout the various views a specific embodiment of the present invention will be described in detail.

While the device of the present invention is capable of a wide range of uses it is particularly adapted for removing the squirrel cage blower from a window airconditioner unit. In FIGURE 1 a portion of such a unit is illustrated and there is shown a squirrel cage blower 1 having a hub 2 and mounted on a motor shaft 3 journaled in a wall 4. Closely spaced from the open end of blower 1 is a housing 5 for cooling coils 6. The space between the blower and the housing is generally of the order of about 1 /2 inches. The blower hub 2 is secured to the shaft by means of set-screw 7. Positioned on the hub 2 is the device of the present invention indicated generally at 8 and shown in greater detail in FIGURE 2.

The device 8 comprises a block-like body 9 which may be rectangular in cross-section and has opposed fiat faces 10 and 11. The thickness of the body which is the distance between opposed faces 10 and 11 is preferably less than the diameter of hub 2.

There is a bore or socket 12 formed in edge 13 of the body with a diameter slightly greater than that of the hub 2 so as to closely receive the hub therein. As indicated at 14 the socket 12 will open to both of the opposed faces 10 and 11.

A locking groove 15 is formed in one or both of the opposed faces 10 and 11 and opens to the socket 12.

There is a second bore within the body 9 and indicated at 16 in FIGURE 4. The bore 16 is for the purpose of accommodating the end of shaft 3 protruding outwardly beyond hub 2. The bore 16 is coaxial with the bore or socket 12. There is a coaxial bore 17 threaded into the body 9 for receiving a puller screw 18 having preferably a square head 19. The puller screw is of sufiicient length so that when at least partially threaded into its bore 17 it engages the end of motor shaft 3.

There is a lateral bore 20 in the body 9 for accommodating a set-screw 21 which engages the outer periphery of the hub when the hub is positioned in socket 12 to grip the hub within the device.

As many be seen in FIGURE 3 a second locking groove 22 may be provided on face 10.

In using the puller device of the present invention, the blower set-screw 7 is first loosened by an Allen wrench and then backed off so that set-screw protrudes about A; of an inch above the surface of hub 2. In some instances it may be desirable to remove the hub set-screw completely and insert an Allen cap screw with an unthreaded shank portion and then threading the threaded portion of the cap screw into the hub. This would result in a portion of the cap screw protruding outwardly of the hub periphery.

The puller device 8 which is less than 1 inch thick can then be readily inserted between the blower and the casing and positioned over the hub 2 and shaft 3 as shown in FIGURE 1. The device is then rotated slightly so that the protruding set-screw 7 is received in one of the locking grooves or 22.

The shaft 3 is then suitably gripped so as to prevent its rotation and a wrench such as indicated at 23 in FIGURE 1 is placed over the square head 19 of the puller screw 18. By means of the wrench, the puller screw is threaded into the body to engage the end of shaft 3. Continued threading of puller screw will push the shaft inwardly with respect to the hub 2 while the hub remains stationary and is prevented from axial movement by means of the device 8. Because of the tremendous force exerted by the puller screw against the shaft the hub is unloosened from the shaft. Once the blower has been loosened from the shaft, the motor and shaft can be backed up and the blower then rolled out of the unit or as shown in FIGURE 1 can be lifted laterally upwardly from the unit. It is thus apparent that both the motor shaft and the squirrel cage blower are undamaged and can be reused.

It is understood that the socket or bore for accommodating the hub can be made of different diameters in order to accommodate different sized hubs. Generally speaking, there are four conventional sizes of squirrel cage blowers used in such air-conditioner units and accordingly a separate wrench must be provided for each of these blowers. However, the body of the device of the present invention could be readily modified to accommodate inserts with each insert having a socket or bore for fitting a particular size blower hub.

It is estimated that in about 75-85 percent of the time the squirrel cage blower set-screw can be used as the lock for the puller device of the present invention. In those cases where the set-screw cannot be used, a cap screw can be inserted in its place as described above.

Thus it can be seen that the present invention discloses a wrench type device which can be effectively employed to remove blowers, pulleys and other similar structures having a hub mounted on a shaft. The present device is particularly useful in those installations where accessibility to the hub mounted on the shaft is particularly difiicult or limited. The present device is extremely simple in structure and function and effectively utilizes the set-screw of the hub for locking the hub within the device while an axial force is exerted against the shaft upon which the hub is mounted by means of the puller screw in the device. The use of the subject device in removing squirrel cage blowers not only saves a considerable amount of time, but also enables the blower and motor shaft to be used again since neither is damaged during the removal process.

It will be understood that this invention is susceptible to modification in order to adapt it to different usages and conditions, and accordingly, it is desired to comprehend such modifications within this invention as may fall within the scope of the appended claims.

What is claimed is:

1. A device for removing from a shaft a squirrel cage blower, pulley and the like having a hub secured to the shaft by a set-screw, and comprising a block-like body having a pair of opposed faces, there being a bore in an edge of said body having a diameter slightly greater than the diameter of said hub so as to recevie the hub therein, means on said body comprising a locking groove extending radially from said bore for lockingly engaging said hub set-screw against axial movement of said hub when said hub is received Within said body first bore, there being a second bore in said body opening into said first bore, and coaxial therewith for receiving the shaft end, means on said body for gripping the hub when said hub is with in said first bore, a puller screw threaded into said body coaxial with said first and second bores and extending into said body coaxial wit-h said first and second bores and extending into said second bore when partially threaded into said body so as to engage the end of the shaft received therein, the device being placed over the shaft end to receive the hub and shaft in the first and second bores respectively after the hub set-screw is unthreaded to a protruding position and the device being rotated to receive the hub set-screw within said set-screw locking means whereupon the puller screw is threaded into the body block to loosen the shaft from the hub.

2. A device as claimed in claim 1 wherein the thickness between said opposed body faces is less than the diameter of the hub, said first bore opening to both of said opposed faces and said locking groove being in one of said opposed faces and extending into said first bore.

3. A device as claimed 1 with said hub locking means comprising a set-screw threaded within said body and engageable with the peripheral surface of said hub when the hub is received within said first bore.

References Cited UNITED STATES PATENTS 1,318,l37 10/1919 Dunlap 29263 1,355,028 10/1920 Blessing et al 29263 1,857,211 5/1932 Odlum et al 29-257 1,956,924 5/1934 Kulp et al. 29259 MYRON C. KRUSE, Primary Examiner.